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.

Just Another Day at the Office

Posted: November 2nd, 2011 | Author: Administrator | Filed under: Fuel & Air, Motorcycle Repair | No Comments »

Steve,

Of course Robt. and I had a collegial discussion on the way home regarding your bike – theorizing, hypothesizing, and devising tests of those hypothesis. So nothing would do when we unloaded your bike but to get it up on the lift and put our chat to work.

First thing, I put my meter on the battery – expecting it to be very low as per the clicking solenoid. Not so! A full and robust 13v. Still, it’s amps that spin the starter, not volts so I hauled over my big shop battery – retired from daily duty in my truck – and jumper-cabled it to your system. Same thing – click click – no joy. Finally, I cabled the shop battery directly to the starter motor. There a perceptible vibration an electric motor makes when it’s drawing all the juice but cannot turn – and your motor made it.

Now my working hypothesis is that the starter motor has seized. Time to remove it and bench test it. This required removing the left side engine alternator cover. I did not put a drain pan under the engine as there is no oil in the alternator/rotor bay. Pulled the array of 8mm bolts, gave the cover a tap with the dead-blow hammer to break the seal …

… and out poured gasoline – gushing gasoline. I removed the sparkplug and the cyl. was full to the top with gasoline. There was nothing wrong with the battery or the starter – liquid is incompressible and the cyl. was full. This is something called a “hydro-lock” and it usually results in a bent connecting rod. I put the bike in gear, shifted up to top, and turned the engine over with the rear wheel – which launched great jets of gasoline toward the ceiling. The crankcase and the air filter box were also filled with gasoline.

I have a good collection of retired cotton bed sheets that I use for dust covers when I remember them and it took a half-dozen or more of them to mop up the shallow lakes of gasoline on the lift table and floor. One spark …

I let everything drain for a while and then filled the crankcase, and turned the engine over with the spark plug removed to pump fresh oil through the system before it had to sustain the forces of combustion. I did a compression test and got 155 on a cold engine – a very good number. Fitted a new D8EA and turned it over with the choke off and the throttle wide open – the field-expedient treatment for a flooded carbureted engine. First a cough and then a few more – and whoo hee! We have self-sustaining combustion. And the engine sounds smooth and happy – not a hint of the dreaded bent con-rod.

So, why did your engine fill will gasoline? I tested the petcock – the vacuum-operated petcock with the manual over-ride in the “Prime” position. The petcock is working as designed so, after filling it, you must have left it overnight with the petcock on Prime – which I specifically instructed you was to be used only if/when the tank had run dry and the carb sucked air as it sputtered to a stop. In that case, the carb needs to be Primed – filled with fuel prior to staring the engine. Otherwise it stays in the On or Reserve positions.

But we have a second question to answer as well; if the float/float-needle/needle seat are all on the job, the flow of fuel from the tank should have been shut off by the float needle fitting into its seat. But it wasn’t. I think the clue is in the fact that you filled the tank up from nearly empty – and I bet that I find another layer of sediment in the carb float bowl. But wait! There is one other possibility – and the more likely, now that I think of it – is that the damage I showed you on one of the posts for the float pivot pin was worse than I assessed and somehow caused the float to stick open. I will investigate this tomorrow.

This is an example of the tension between saving the customer money by reusing less than perfect parts or giving them back a bike that breaks down again. Mostly my judgement is pretty good and less than perfect parts can and do give long and faithful service. Sometimes I’m wrong – in retrospect, that is. The easy thing would be to simply use new parts all the time – effectively charging my customers to cover my ass. But I do believe in using/reusing as much of our way-too-much stuff as we can.

So, all of that may or may not have something to do with the problems you were experiencing pre-fill-up. I will keep your bike for a couple of days and take it on a few short hops – perhaps as far as Weaverville. If it is trouble-free, the plan is for Robt. to take it home to his place in Marshall and have you drive your car to meet him there for some schooling.

You’re into me for a couple of hours/$110 and half of the normal pick-up fee – $25 -I’m eating half on the possible hanging float but you left the petcock in the Prime position.

A good used carb body may be required – but a whole good used carb bought to get it. Figure $100 +/-. plus another hour or so of my time.

And that’s the news from Existential Motorcycles this evening.

Cheers,

Chris

Existential Motorcycles
Alexander, NC 28701

TEL: 828-683-9289



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