My shop is in an over-sized two-car garage attached to my home. My work is a calling, in the theological sense of the word. Ethical and moral questions arise every day – they are hard, sharp, unambiguous and unavoidable.

The Wretched Truth of How I Fix Things – An Epistolary Example

Posted: April 10th, 2014 | Author: Administrator | Filed under: Motorcycle Repair | No Comments »

Josh,

I kinda back-burnered your bike for a week or so to deal with a couple of minor crises but got back on it today – even took it out for a short test-spin.  The chassis is tight and handles very well but the motor would only run cleanly on the main jet – half to full throttle at medium or higher revs.

It’s hugely rich at/off-idle.  To  get it to fire and run, I have the throttle stop screws full-in and the pilot air screws full-out – both should lean the mixture excessively.  I have stripped both carbs and they are clean as a whistle.

In the course of double-checking my work – ignition timing, valve clearances – I did a compression test and the numbers are very good – 165 psi on both.  When the rings are fully-seated you should see 175 psi.

I’m really having a hard time getting my head around your word that it idled nicely and pulled cleanly before it blew up.  I removed and reinstalled the carbs [Mikuni VM32s] without opening them up.  All the jetting and adjustments were exactly as they came to me.

Please note well – I am not saying it did not run well – just that I am at a loss as to understand why it is not now.

What it is running like is an over-carbureted engine.  Tomorrow I am going to bolt on a stock set from a good-running CB350 and see what happens.  My guess is that it will run the way a freshly-built CB350 engine should.

If not, there is one last ugly possibility – and that is that the cam chain sprocket on the crankshaft is damaged and the cam chain has jumped a tooth.  When I was installing the cams and setting their timing relative to the crank, I had to make several tries to get the cam chain correctly engaged with this sprocket – something one does by feel as it is buried deep in the cases.  I renewed the cam chain tensioner rollers – both of which were badly chewed up and worn.

So, in your own interest – hope that I am right about the carbs.

Cheers,
Chris
Existential Motorcycles
Alexander, NC

______________________________

Joshua,

It runs smooth and strong with the stock carbs and idles like a purring puppy.

I can supply you with a cleaned and rebuilt set of carbs for $100.  I have also emailed Speedmoto that sells VM32 Mikunis allegedly correctly jetted for this bike to ask what jet sizes they use/recommend for this bike.

Give me a couple of days to put together a good set of carbs for you – install and tune them – road test and final tuning.

Cheers,
Chris
Existential Motorcycles
Alexander, NC
_______________________________________________________
Hey Chris, thanks for the update. I’m having some trouble getting my head around it too but if it’s not right it’s not right. I guess if things go smoothly with the stock carbs on then I’ll switch back, do you have anything around the shop you’d be willing to get rid of or should I start looking around for a clean set?

Joshua

______________________________________________________

Joshua,

I knew that bragging on myself about my carb building was tempting the fates – and I was right.  It fired, idled and revved beautifully in the shop – but out on the road with the engine under load it was shit – one cyl. running way rich and the other way lean – or so the plugs were telling me.

This is an object lesson on how one can become fixated on/committed to a diagnosis and forget that there are other possible explanations for the problem at hand.  In this case I have spent most of the last two days taking the carbs out, double-checking my work, making jetting changes/adjustments, reinstalling the carbs, syncing them, taking short test-hops – probably at least ten iterations of this scene – based on the assumption that I was chasing a carburetion problem.

Late this afternoon – as despair was setting in – my brain actually started working again and it occurred to me that problems in the ignition system could cause very similar symptoms.  Turns out – I think – that the underlying problem has been electrical all along – a weak condenser that worked just fine at no load on a cold/warm engine but which began to fail intermittently under load with the engine at working temp.  Because that plug is not firing cleanly on every powerstroke, it soots up and looks just like an overly-rich mixture.   I replaced it and things improved substantially but not perfectly – the spark is still yellow-ish and kinda weak.  Tomorrow morning I am going to test the coils by swapping them out with a pair on another CB350 in my shop that is running well.  If I am actually barking up the right tree this time, I may/should have your bike ready to collect on Sat.  I’ll email you by this time tomorrow with the results.

Thanks for your patience – and welcome to the funky world of vintage motorcycles.

Cheers,
Chris
Existential Motorcycles
Alexander, NC

__________________________________________________________

Joshua,

Well, everything I have done to the ignition system has improved things – to the point where I could probably pass your bike back to you – it runs acceptably now – but I know it is still not right – and now I know the reason why.  In a kinda twisted way, the fact that it is running as well as it is, is a testament to my engine tuning skills.  I put a degree wheel on the left end of the crank – which serves as the alternator mount – and the valve timing is off – the intakes are opening too early and the exhausts closing too late.  You will recall that I earlier considered this as a possibility – but had been happy to let it go – because it would mean taking the engine out again – when I discovered other insufficiencies that could have plausibly been causing the symptoms – and was further seduced into this way of thinking when I kept uncovering genuine defects – fixing them – and improving things.

Lesson: there is always something not quite right with 30+ year-old machines – and usually many things.  The Mikunis were over-jetted, the condenser was breaking down under heat and engine load, the coils were weak.

So out comes the engine tomorrow.

The good news for you is that a.) I am not charging a farthing for all my time chasing phantoms, and b.) that when this saga is finally concluded, you will have one of the best-sorted out vintage bikes on the road. And I ordered the correct jets for the Mikunis and will try them out once the engine is back in.

Thanks for your patience/understanding.

Cheers,
Chris
Existential Motorcycles
Alexander, NC


Float Needles and Blown Fuses

Posted: August 30th, 2013 | Author: Administrator | Filed under: Fuel & Air, Ignition, Timing, & Electrical, Motorcycle Repair | Tags: , | No Comments »

It doesn’t take much at all to cause a float needle to improperly seat and allow fuel to keep flowing. The smallest bit of debris can keep the needle from seating properly and cutting off the fuel flow. Below is an email exchange with a customer regarding such float problems. Also, there are some useful tidbits about diagnosing electrical problems. Enjoy!

Hi Chris, we talked , in past, over phone…I managed to get all plugs in the 83 Venture @ .035 with new OEM(paper element) air filter….I am getting a backfire on deceleration on one cylinder, and idle is just not a consistant solid RPM…vaies, maybe 300 RPM’s at idle…..In your expert opinion, is this a valve adjustment problem and/or carb out of sync? Or, is air filter not breathing as free as it should? Have a great and safe 4th weekend…this is an irratating issue…I drove down to Pickens today and the bike runs smooth enough on the highway….then decelerate and pop goes the weasel….many thanks……need to bring it to an expert….
Respectfully,
W


W,

The symptoms you describe are typical of a cylinder running lean at low rpms. This can be caused by either a carb with clogged up idle/pilot jets or by an air leak. If you can tell which cyl. is the culprit, removal and a thorough cleaning should do the trick. The other possibility is that the rubber intake manifold between the carb and the intake port is cracked and leaking air. Less likely but possible is that the little rubber o-ring sealing the pilot air screw is leaking.

Cheers,
Chris


Hi Chris, I left you a ph message, but here are the symptoms…..1983 Yamaha Venture…one carb is dumping gas and it goes down to ground through short hose….It runs smooth, and strong, but I am wanting to take a trip north (487 mi) to 85 miles SW of Indianapolis camping in KY on way there and back….you can see the gas flow in the carb in question(when air filter is removed), but not other 3 carbs are showing gas flow…Do you think, by adding Sea Foam, to gas line, recently, I could have screwed up the works? Also, I overfilled the tank last saturday, then didn’t drive until yesterday, and noticed gas smell but really had to hunt down leak…..possible vapor lock from heat and expansion yesterday? Anyway, I need to get this fixed….
Many Thanks, Respectfully,
W


Wayne,

My guess is that the problem is that the Sea Foam did its job and dislodged accumulated crud – one little speck of which had lodged in the float needle seat and is preventing it from shutting off the fuel flow to that carb. The overfilling is probably just a coincidence.

An important caveat: I have not worked on a Venture before but a friend of mine has one and there is a lot of stuff to remove before one can put that carb on the bench to work on it. If you have a good shop manual – great – if not, I will need to purchase one – about $30 for a Clymer or Haynes. I can figure out just about anything – given time – and I adjust my hours to reflect what I think it should have taken someone familiar with the bike. But you may prefer to take it to a Yamaha dealer or another mechanic who has experience with this bike. I think, if I were in your shoes, that’s what I would do.

Let me know what you decide.

Cheers,
Chris


Chris,
I traced another caveat: my headlight went out…I took the HL housing apart and cleaned connectors……put it together…still no light….went to fuse box and the head lamp, 10 amp fuse, had burned a hole in plastic fuse housing…I Jerry rigged one annode side of glass fuse with a fashioned connector (what I had available to improvise) and snapped the good side back in…works, but no high beam, so I believe I need a new lamp and a permanent fix for the fuse box defiency…I like working on bikes, but my expertise is limited…Been riding for 42 yrs, and, at 60, still learning new tricks…..my tool kit is my own variety of tools, including cold touch soldering iron, flares, flashlight, night light sticks, electrical & duct tape, fuses, extra plugs, plug gapper, tool to get plugs out and in, Teflon tie sticks, first aid kit, rainsuit, 3 sets of gloves including gaunlet, and misc items for most common fixes…I have running lights, mini-red strobe lights which are motion activated, deer horn alerts(I know they work lol), highway pegs, and a small instrument cluster containing, clock, compass, and thermometer…..these add-ons are for better visability & safety and function…..bike is stock…no mods….Have a great weekend……
Respectfully,
W


Wayne,

The blown fuse means that something in that circuit is drawing more than 10 amps – typically due to either a short or a bad ground. The most likely culprit is inside the light switch module on the handlebar. Less likely is that the headlight itself shorted internally. The fuse exists to protect the electrical components – and from the bike going up in flames – worst case. Juryrigging/bypassing the fuse will – sooner or later – result in much more expensive problems than you have now. If you have a multi-meter you should be able to located the fault and correct it.

Good luck in getting it sorted out.

Cheers,
Chris


What Can a Spark Plug Tell You?

Posted: August 30th, 2013 | Author: Administrator | Filed under: Engine, Fuel & Air, Motorcycle Repair | No Comments »

Knowing how to read a spark plug can give you very helpful insight into what is actually happening inside of your engine. Below is a correspondence I had with a customer explaining what I could deduce from the state of his plugs.

R,

I did a quick and dirty compression test on the cold engine – 140 psi on the left cyl and 150 on the right. These values will increase to around 160 psi when measured correctly on a hot engine – and that’s very good. So your engine is fundamentally sound and I can procede with the work.

Significantly, the two spark plugs looked very different and yeild clues as to the poor performance. The insulator tip can be read to give a good idea of what’s happening in the combustion chamber. The left plug was black with an oily sheen while the right was nearly white and dry. I suspect that one of the valve guide seals on the left cyl is allowing oil from the cams down the valve stem into the cyl and that the right cyl is running way too lean. I’ll take another plug reading after I have cleaned/rebuilt/adjusted the carbs. If the oil fouling on the left cyl is not too bad, it may be better/cheaper to just replace that plug once in a while rather than pull the head to install new seals. Plugs are cheap and easy to replace. Valve guide seals are not.

Cheers,
Chris


The Wretched Truth About Restorations

Posted: December 13th, 2012 | Author: Administrator | Filed under: Editorial, Engine, Forks & Steering, Frame & Body, Fuel & Air, Ignition, Timing, & Electrical, Motorcycle Repair, Wheels, Tires, & Brakes | Tags: , | 4 Comments »

Greetings Chris,

I have researched available motorcycle restoration shops on the East Coast and have found your shop one of the best suited for my project. I would like to determine if your willing and able to restore a vintage Yamaha 80 enduro shown in the pictures attached? If so, to what level of restoration are you capable of achieving? And how long would this take? Further, what ballpark pricing can you provide?

Regards,
R

_____________________

R,

Thanks for your note of inquiry – and the very flattering words about my shop and work.

First, I need to know that you know the First Law of Restorations; you will end up spending waaaaay more than the finished product will fetch on the open market – two to three times more is the rule of thumb – and the multiple is higher with smaller displacement bikes.

So let’s see if I can scare you off right now. Mechanical restoration/rebuilding will run $3k – half parts and half my time. Cosmetic restoration will be another $3k – about half for first-rate factory correct paint and decals and half for re-chroming which, when properly done, means stripping the old chrome from the part, filling the deeper rust pits and other defects with a conductive metal filler, a heavy layer of copper plate to fill the smaller pits, a layer of nickle to keep the copper from showing through the final layer of chrome. This process is sometimes called “triple chrome.” Better add another $1k to cover things like tires, seat re-upholstery, and this, that, and the other thing. That’s $7k – and no matter how realistically I think I am estimating time and money, everything takes longer and costs more than I had expected – even when I know this and take it into account. That may be the Second Law of Restorations; everything will take longer and cost more than even your worst-case estimate. A final bill of $8k could happen. And all this for a bike that will be worth no more than $3k when done – probably closer to $2k.

I have been doing this stuff long enough to have learned a few things; nobody ever complains about getting a bill less than they expected. Dealing with a panicky customer as the running estimate is regularly revised upward is no fun. I’d rather scare you to death right now.

I’ve just come in from the shop – 11pm – after an afternoon favor checking out a problem on my sweetie’s son’s bike turned into eight hours of pro-bono work – time for a bit of supper.

Cheers,
Chris
Existential Motorcycles TEL: 828-6839289 Web: http://www.existentialmotorcycles.com
Alexander, NC 28701

______________________

Greetings Chris,

Thanks for your carefully thought out email below. Your thoughts and details provided are worth close observation and consideration. With the economy in its current state and no prospects for any improvement in the foreseable years ahead, I must fully think through what makes sense for me moving forward. I will let you know if I decide to proceed in the coming months.

Happy Holidays and warm regards,
R

________________

R,

Thanks for taking my bucket of cold water over your head so well.

Now I can ethically add that there are many excellent non-monetary reasons/rewards for/from restoring a bike – all better reasons, in my way of reckoning, than money.

And it could be done in two stages; mechanics/functional restoration one year and the pretty bits the next.

But it will be expensive and time-consuming.

Under no circumstances should you compromise your financial health to take on a proper restoration. It sucks all the fun out of it – and the damned bike becomes the cause of it all. And I become the dealer man for whom you are stealing the children’s lunch money to feed your habit. Pure poison. If/when you do this, have the cash on hand and set aside.

I do take extensive notes as I work and lots of digi-pix. On long-term projects I send these as updates every day or so – kinda helps the customer come along for the ride – and adds considerable value to the results – builder’s notes and documentary pix impress the hell out of buyers. But most of all, it’s fun for everybody. I enjoy telling stories of the day’s work and it helps me to review my work and confess my sins. Yes, I break the code of the Mechanics’ Guild and freely admit that I make mistakes and, sometimes, really fuck things up. I’ve made just about every damned-fool mistake you can think of and broken every tool and part. But a funny thing happened – as the years rolled by I made fewer and smaller mistakes. I still make mistakes – sometimes even dumb ones – but for quite a while now (knock polished alloy) they have been non-catatrophic and recoverable errors. And every one still a lesson of some sort.

Cheers,
Chris

Existential Motorcycles TEL: 828-6839289 Web: http://www.existentialmotorcycles.com
Alexander, NC 28701


So you think you want a custom cafe racer?

Posted: November 19th, 2012 | Author: Administrator | Filed under: Engine, Forks & Steering, Frame & Body, Fuel & Air, Ignition, Timing, & Electrical, Motorcycle Repair, Random Things of Interest, Wheels, Tires, & Brakes | Tags: | No Comments »

Greetings,

The following in the first installment of correspondence between me, a would-be cafe-racer builder, and one of his customers. The customer was so appalled at what was delivered to him that he forced the builder to bring the bike to me and pay me to put things right.

Caveat emptor!

Chris


John and Casey,

This is the first in a short series of illustrated reports on my findings and work on your bike.

It will be difficult reading for both of you – and it is difficult work and writing for me. I began work on your bike last evening and had to quit after 1 ½ hrs. as what I was finding was making me increasingly angry.

In short, this bike was built/assembled by a dangerously incompetent person who should never be allowed to work on a vintage motorcycle again – unless they are willing to apprentice for a couple of years with someone who knows what they are doing.

Report – Initial Inspection:

Compression test: L = 190 psi and R = 175 psi. on a cold engine.

Since the spec on a new engine is 175 psi., these numbers suggest a substantial build-up of carbon on the piston crown and head. I will put a bore scope down the spark plug hole today and have a look. Also I’ll do a leak-down test. For the price of this bike – $7k – it should have a freshly-built engine, not just a freshly-painted engine.

The electronic ignition module is located in the worst possible place on the bike – directly in front of the leading edge of the rear tire with no intervening fender or other shield to protect it from the grit/crud/spray hurled at it by the spinning rear wheel. I will relocate it or shield it.

The front brake is dragging badly – and it’s a simple drum brake – the adjustment of the cable/actuating mechanism is just too tight. Again, no excuse for this. A simple pre-delivery inspection would have caught this. No bike should leave a shop with compromised brakes.

All three Phillips head screws for the cover on the centrifugal oil filter had seized and the heads stripped out. The rust pattern in the stripped screw heads shows that no attempt was made to remove the stripped screws and replaced with good ones so that the new owner could access/clean the filter. Which suggests that the person who built this bike did not clean the filter either.

Working carefully, I was able to remove all three screws in about 30 minutes. The pix below show what I found and how I fixed it. They also show the inside of the centrifugal filter and what I found in there – the usual black sludge but with lots of small bits of metal embedded in it – steel as it sticks to the head of a magnet. This probably comes from the transmission gears and suggests that it has been treated badly at some point in its past.

First I drilled out the heads of the stripped screws a bit and then hammered a 3/8” drive torx bit into the hole. Anoint with penetrant, heat with MAPP gas, and attach impact driver to the torx bit. One good whack with a 3 lb. Short sledge and voila. Well, almost. The threads of the top/left screw were stuck so badly that I just twisted the head off the screw shank. Fortunately, I was able then to carefully lift the cover off and then get a grip in the bit of shank protruding from the case.

And finally, two of the four bolts holding the footpegs to the frame were badly cross-threaded and one on the right side had jammed half way in and been left like that, here’s the pic.

Not only does the shoddy/dangerous workmanship offend me, I am dumbfounded by the fact that the person who assembled this bike did not think or care that anyone would notice.

I am posting this series of correspondence on my website – minus your names – as a bit of a caution to folks buying a custom-built bike and to those who think that capitalizing on the cafe-racer fashion is an easy quick buck.

John, I am roughing up you and your biz – and it’s got to hurt. But it’s the truth. If you can’t stand it, refund C’s money in full and get out of the biz. Otherwise, do the harder/right thing and take it and learn from it.

Sincerely,

Chris Finlayson
Existential Motorcycles
Alexander, NC


John and Casey,

This is the first in a short series of illustrated reports on my findings and work on your bike.

It will be difficult reading for both of you – and it is difficult work and writing for me. I began work on your bike last evening and had to quit after 1 ½ hrs. as what I was finding was making me increasingly angry.

In short, this bike was built/assembled by a dangerously incompetent person who should never be allowed to work on a vintage motorcycle again – unless they are willing to apprentice for a couple of years with someone who knows what they are doing.

Report – Initial Inspection:

Compression test: L = 190 psi and R = 175 psi. on a cold engine.

Since the spec on a new engine is 175 psi., these numbers suggest a substantial build-up of carbon on the piston crown and head. I will put a bore scope down the spark plug hole today and have a look. Also I’ll do a leak-down test. For the price of this bike – $7k – it should have a freshly-built engine, not just a freshly-painted engine.

The electronic ignition module is located in the worst possible place on the bike – directly in front of the leading edge of the rear tire with no intervening fender or other shield to protect it from the grit/crud/spray hurled at it by the spinning rear wheel. I will relocate it or shield it.

The front brake is dragging badly – and it’s a simple drum brake – the adjustment of the cable/actuating mechanism is just too tight. Again, no excuse for this. A simple pre-delivery inspection would have caught this. No bike should leave a shop with compromised brakes.

All three Phillips head screws for the cover on the centrifugal oil filter had seized and the heads stripped out. The rust pattern in the stripped screw heads shows that no attempt was made to remove the stripped screws and replaced with good ones so that the new owner could access/clean the filter. Which suggests that the person who built this bike did not clean the filter either.

Working carefully, I was able to remove all three screws in about 30 minutes. The pix below show what I found and how I fixed it. They also show the inside of the centrifugal filter and what I found in there – the usual black sludge but with lots of small bits of metal embedded in it – steel as it sticks to the head of a magnet. This probably comes from the transmission gears and suggests that it has been treated badly at some point in its past.

First I drilled out the heads of the stripped screws a bit and then hammered a 3/8” drive torx bit into the hole. Anoint with penetrant, heat with MAPP gas, and attach impact driver to the torx bit. One good whack with a 3 lb. Short sledge and voila. Well, almost. The threads of the top/left screw were stuck so badly that I just twisted the head off the screw shank. Fortunately, I was able then to carefully lift the cover off and then get a grip in the bit of shank protruding from the case.

And finally, two of the four bolts holding the footpegs to the frame were badly cross-threaded and one on the right side had jammed half way in and been left like that, here’s the pic.

Not only does the shoddy/dangerous workmanship offend me, I am dumbfounded by the fact that the person who assembled this bike did not think or care that anyone would notice.

I am posting this series of correspondence on my website – minus your names – as a bit of a caution to folks buying a custom-built bike and to those who think that capitalizing on the cafe-racer fashion is an easy quick buck.

John, I am roughing up you and your biz – and it’s got to hurt. But it’s the truth. If you can’t stand it, refund C’s money in full and get out of the biz. Otherwise, do the harder/right thing and take it and learn from it.

Sincerely,

Chris Finlayson
Existential Motorcycles
Alexander, NC


John and Casey,

This is the first in a short series of illustrated reports on my findings and work on your bike.

It will be difficult reading for both of you – and it is difficult work and writing for me. I began work on your bike last evening and had to quit after 1 ½ hrs. as what I was finding was making me increasingly angry.

In short, this bike was built/assembled by a dangerously incompetent person who should never be allowed to work on a vintage motorcycle again – unless they are willing to apprentice for a couple of years with someone who knows what they are doing.

Report – Initial Inspection:

Compression test: L = 190 psi and R = 175 psi. on a cold engine.

Since the spec on a new engine is 175 psi., these numbers suggest a substantial build-up of carbon on the piston crown and head. I will put a bore scope down the spark plug hole today and have a look. Also I’ll do a leak-down test. For the price of this bike – $7k – it should have a freshly-built engine, not just a freshly-painted engine.

The electronic ignition module is located in the worst possible place on the bike – directly in front of the leading edge of the rear tire with no intervening fender or other shield to protect it from the grit/crud/spray hurled at it by the spinning rear wheel. I will relocate it or shield it.

The front brake is dragging badly – and it’s a simple drum brake – the adjustment of the cable/actuating mechanism is just too tight. Again, no excuse for this. A simple pre-delivery inspection would have caught this. No bike should leave a shop with compromised brakes.

All three Phillips head screws for the cover on the centrifugal oil filter had seized and the heads stripped out. The rust pattern in the stripped screw heads shows that no attempt was made to remove the stripped screws and replaced with good ones so that the new owner could access/clean the filter. Which suggests that the person who built this bike did not clean the filter either.

Working carefully, I was able to remove all three screws in about 30 minutes. The pix below show what I found and how I fixed it. They also show the inside of the centrifugal filter and what I found in there – the usual black sludge but with lots of small bits of metal embedded in it – steel as it sticks to the head of a magnet. This probably comes from the transmission gears and suggests that it has been treated badly at some point in its past.

First I drilled out the heads of the stripped screws a bit and then hammered a 3/8” drive torx bit into the hole. Anoint with penetrant, heat with MAPP gas, and attach impact driver to the torx bit. One good whack with a 3 lb. Short sledge and voila. Well, almost. The threads of the top/left screw were stuck so badly that I just twisted the head off the screw shank. Fortunately, I was able then to carefully lift the cover off and then get a grip in the bit of shank protruding from the case.

And finally, two of the four bolts holding the footpegs to the frame were badly cross-threaded and one on the right side had jammed half way in and been left like that, here’s the pic.

Not only does the shoddy/dangerous workmanship offend me, I am dumbfounded by the fact that the person who assembled this bike did not think or care that anyone would notice.

I am posting this series of correspondence on my website – minus your names – as a bit of a caution to folks buying a custom-built bike and to those who think that capitalizing on the cafe-racer fashion is an easy quick buck.

John, I am roughing up you and your biz – and it’s got to hurt. But it’s the truth. If you can’t stand it, refund C’s money in full and get out of the biz. Otherwise, do the harder/right thing and take it and learn from it.

Sincerely,

Chris Finlayson
Existential Motorcycles
Alexander, NC
Bad location for sensitive electronics


Too cool for words

Posted: July 1st, 2012 | Author: Administrator | Filed under: Pix, Random Things of Interest | No Comments »

http://www.jockeyjournal.com/forum/attachment.php?attachmentid=41623&d=1241114018


Value, Price and Values; “What’s it worth?” Nothing – nothing compared with a good meal, warm clothes, a lover’s touch, a stranger’s smile. Nothing at all.

Posted: May 14th, 2012 | Author: Administrator | Filed under: Engine, Motorcycle Repair | 1 Comment »

To: chris@existentialmotorcycles.com
Sent: Sunday, May 13, 2012 7:40 PM
Subject: Suzuki 1974

Hi Chris I saw your Craiglist add, I have a 5900 mile tc100, I have attached a short movie showing the bike. I replaced the carb and the coil. it will start, but has a oil leak in the middle seal, I would love to keep the bike, but I dont believe I have any of the tools it would take to completely dismantle the motor. I have a new Gasket for it. If you were looking to purchase it how much is one worth. I have some new parts for it and the original owners Manuel, and a service manual. I got it without certificate of ownership so there is no known title for it.

Thanks for your time, To clear my mind how much to fix it?

A

_____________________________________________________________________________________

A,
Thanks for your note of inquiry.  My computer w/Windows Media Player did not recognize your attachment – but I can tell you a few things that might be useful in setting a range of values for your bike.
Two-strokes gave four-strokes a run for their money for 20 years – ’60s-’80s – and another twenty years for dirt bikes.  But the 2-stroke is now officially a dead-end technology – like steam power for automobiles – and while orphan technologies will always have a happily-demented following – http://www.stanleysteamers.com/ – they don’t get much respect from the general collector market – and that’s what set’s the benchmark values for 20+ year old motorcycles.
Then there is the American Fallacy Factor.  The American Fallacy is this:  if X is good, then 2X is better.  Full-stop, no-doubt-about-it.  Tiddlers get no respect from the market.  Since your bike is roughly 1/10th X ….
So, if your bike is all-but-be-damned show-room new and is functionally flawless, it would do well to fetch $1k.  And the decline in value for decline in cosmetic/mechanical condition below this standard is not a linear function.  I don’t know the correct word/phrase but relatively small declines in condition precipitate large declines in market value.  On the other hand, the price of rebuild/restoration parts does not decline with the value of the bike that needs them.  Thus, a less-pricey-to-purchase bike – which will need lots of parts – can end up being more expensive to repair/restore – which further depresses their value.    If your bike is complete – all original parts present and accounted for – it looks okay (no dents/rips/rust) and it runs okay sort-of, it’s maybe a $300 bike.  Same but not a runner, $100.  A motorcycle-shaped collection of rusty parts – $0. I have said, “Some of the most expensive bikes I’ve owned, I got for free.This bizz can get complicated – and that’s what makes it entertaining and instructive.

To fix it means splitting the cases, extracting the crank, renewing the seals, and putting it all back together again.  Since the time is the same whether I install the old pistons and rings or new items, it makes sense to refresh the top end with new piston and rings – 6k mi. can be a lot on a vintage small-bore 2-stroke.  But that’s another $200 in parts/machine shop.  My time would be 4-8hrs – @ $60/hr. – depending on how many stripped/seized fasteners and otherwise buggered parts I run into in the process.
There are many excellent reasons for restoring a funky old bike, but rational economic self-interest is not among them.
Cheers,
Chris
Existential Motorcycles        TEL: 828-6839289         Web: http://www.existentialmotorcycles.com
Alexander, NC 28701

An engine’s tale

Posted: May 8th, 2012 | Author: Administrator | Filed under: Engine, Motorcycle Repair | Tags: | No Comments »

J & N,

If resurrecting moribund old Honda engines is holy, then I’m on my way to sainthood. Did you know this one was seized? Not badly, as it turned out, and only on one side.

The attached pix will show you what I found as I went along.

See that one spark plug hole has been stripped, drilled out for an insert, and that has been buggered so that no plug was in the hole – for quite a while judging by what I found inside.

The heads of the screws holding the alternator cover in place were long gone. At the point of the picture, I had cut a slot in the heads of two with a small cold chisel sized to fit the blade of one of my impact driver bits. That moved them. If it hadn’t, there was one more possible move before drilling them out.

Now, with a 14mm socket on the end of the crank, I am sure that the engine is stuck.

The head came off relatively easily as I have been anointing all the fasteners with PB Blaster for the past few days.

I cleaned the debris out of the stuck cyl/piston and covered it in a pool of PBB to soak overnight. This afternoon I placed a 1″ hardwood dowel atop the piston and gave it a short stroke with 2lb. brass hammer. Tapping alternately the top of one piston and then the other eventually began to move the piston and soon I had it free enough to pull the cyls. up off the pistons.

This was likely a newly-built engine on its first overbore – the bores are roughly 64.25 mm. and have no taper or ovaling. The pistons are straight and square too. But the machinist who did the boring did not leave sufficient piston/cyl. clearance – the pistons are larger than nominal spec – and the engine had a light seizure – or two. The next thing that happened was that whoever responded to the seizure got that plug cross-threaded and stripped – or perhaps the heat of seizure stuck the steel plug hard in the alloy head.

The man with the wrench is already pissed off. His brand-new engine has just puked and now he’s gone and made things even worse. Out comes the hand-held power drill and a heli-coil insert. And you can guess the rest. The poor beaten bastard just dropped his tools and walked away leaving that cyl. open to the atmosphere.

Every engine – every machine – tells me stories about it’s history. My work is kind of archaeology – digging into the past, interpreting the traces/evidence of those who have gone there before.

I’ve 3.5 hrs. in so far inc. researching best available prices for pistons/rings/pins, tensioner, cam chain, etc. The only set of NOS Honda pistons I could find in the US was fouth-over (last overbore) and with rings sourced from elsewhere would have been more $ than the set I have ordered from the place in the Netherlands I have used before with satisfaction. They also had the best combo price for the tensioner body/small roller and the big roller. But their cam chain was twice what I can get a good one for here. The parts were 219 Euros which is around $290. With shipping it’s about $320.

Cheers,
Chris

Existential Motorcycles TEL: 828-6839289 Web: http://www.existentialmotorcycles.com
Alexander, NC 28701


Cleaning/lining a gas tank

Posted: April 1st, 2012 | Author: Administrator | Filed under: Fuel & Air, Motorcycle Repair | 4 Comments »

If it’s not leaking, just clean and de-rust it and put a filter in the fuel line to the carbs. The risks of a less-than-perfect lining job are greater than the benefits – on a non-leaking tank. If the liner starts to come off, it’s pretty much curtains for the tank.

The right way to clean a tank is to first mechanically remove as much rust/crud from the inside as possible. Get a length of light chain – the stuff sold in hardware stores in bulk for hanging lights and so forth is ideal. The length is not important – 3-6ft. is fine. Some folks use a large handful of nuts/bolts – which works – but it can be hard to get them all out again. The chain is easy.

Put the chain in the tank with a quart/liter or so of kerosene. Lay a plastic shopping bag over the filler hole and then close the cap. This keeps the kero from finding its way out the vent in the cap. Now shake the tank turning it this way and that. So it until your arms get tired and then set it aside. Repeat this a number of times until the rust and crud has been scoured away and the metal is clean and bright. Extract the chain and drain off the kero/crud solution. Rinse with fresh kero until it comes out clear. Pour in a quart or so of Evap-o-rust or similar de-rusting solution. They are all based on phosphoric acid which chemically converts iron oxide – rust – to a moderately inert ferric phosphate. I use Milkstone Remover – a dilute solution of phosphoric acid sold through Tractor Supply for cleaning dairy lines. I mix it 1:5 with water – making six gallons – in one of those large blue plastic storage totes from Kmart/Target/etc. Now I can fill a tank with de-rusting solution and let it sit for a day or so. This stuff is highly reusable – and you can just toss smaller rusty bits in the tote. At this weak concentration, the acid is completely safe – you can put your bare hand in it. If you have a cut or nick, it will sting just a little bit.

Here’s a bit from Wikipedia on the chemistry:

“Phosphoric acid may be used as a “rust converter”, by direct application to rusted iron, steel tools, or surfaces. The phosphoric acid converts reddish-brown iron(III) oxide, Fe2O3 (rust) to black ferric phosphate, FePO4.

“Rust converter” is sometimes a greenish liquid suitable for dipping (in the same sort of acid bath as is used for pickling metal), but it is more often formulated as a gel, commonly called naval jelly. It is sometimes sold under other names, such as “rust remover” or “rust killer”. As a thick gel, it may be applied to slopi ng, vertical, or even overhead surfaces.

After treatment, the black ferric-phosphate coating can be scrubbed off, leaving a fresh metal surface. Multiple applications of phosphoric acid may be required to remove all rust. The black phosphate coating can also be left in place, where it will provide moderate further corrosion resistance (such protection is also provided by the superficially similar Parkerizing and blued electrochemical conversion coating processes).”

If the tank is still solid and leak-free, just use it as is but fill it with Stabil-treated gas if it’s going to sit unused for more than a couple of weeks.

If, however, you want or need to line the tank, your work has just begun.

Rinse the tank well with water – several times – to remove all traces of acid. Now dry the inside with compressed air or a hair dryer on low heat. You can speed up things by shaking/blowing most of the rinse water out and putting the tank in a slow oven – about 120-150 degrees F – for a couple of hours. Shake the tank – if you can hear any liquid inside, it’s not done yet.

Now let the tank cool, if you have used the oven method of drying, and then pour a quart of acetone in. Replace the cap and shake well turning the tank over and round about. This does two things; it picks up and eliminates any remaining traces of water and leaves the surface squeaky clean for max adhesion of the line.

The coating should be applied immediately. The acetone washed metal will flash-rust very quickly. Use a liner that is explicitly resistant to the ethanol that is present in most gasoline these days. Good liner is expensive – Caswell’s and POR-15 are said to be very good. I use Red-Kote, and industrial tank liner available through some auto parts stores for around $60/gal. I thin it with MEK – nasty nasty stuff put the only thing that will thin this stuff – and give the tank a thinned wash coat first to ensure that it penetrates every tiny nook/cranny/pore. It needs to air-dry for a couple of days before applying the second un-thinned coating – which needs to dry several days before contact with gasoline. The nice thing about having way more liner than you need is that you can pour lots into the tank to ensure that the coating reaches/covers everything – but you must take pains to ensure that all of the excess drains out so that what remains dries completely before contact with fuel.

If you are using a coating, you must either first remove the petcock and plug those holes or use a crummy old petcock as the sacrificial plug. Also make sure you put a layer or two of plastic between the filler cap and the hole before closing the cap. Otherwise, the liner can plug the vent hole in the cap and your tank will not flow gas to the carbs.


Tuning pilot air screws

Posted: March 13th, 2012 | Author: Administrator | Filed under: Fuel & Air, Motorcycle Repair | No Comments »

NOTE: the following is for twin cyl. engines – and singles too.  Fours will not idle on one cyl. so an external tachometer is needed to fine-tune them.  But, in general, just setting the screws to the spec listed in the service manual will be just fine.

Setting the pilot air screws is fairly simple.  Raise the idle speed sufficiently that it will idle on one cyl. when you pull the plug cap off the other.  Turn the idle speed down as far as you can without the engine dying.  Turn the screw in/out until you have found the spot of highest idle.  As the idle rises, turn the idle adjuster to keep the idle as low as possible.  You can hear changes in idle speed better at the slowest possible idle.  Initially, make the changes a 1/2 turn at a time and pause for ten sec. or more to let the change take effect – there is a lag.  Once you have found the highest idle, repeat but make the changes 1/4 turn.  Repeat with 1/8 turn changes.  When done, make sure the idle is as low as it will go.
Now repeat for the other cyl.
Replace both plug caps and turn the idle down to 1.2k rpm or so.
That’s it.

If you want to go all techie, you can buy an external tachometer with an inductive pickup – but the old guys did it by ear.