Ride 2 miles, engine dies...?

[montmil]

Since purchasing my R65 in late April, I have spent many hours rehabilitating the bike with little opportunities to ride.

Today, after getting the vapor instrument cluster wired up (that post will follow shortly), I launched for a short ride before our grandson arrived.

Two miles from the house, the engine died just as if the ignition was cut off. No stumble, no one-cylinder running, nada, nuttin', just quiet. This is the second time I've taken the bike out - still no current tags or inspection - and the second time the engine has quit within two miles. Too strange.

After waiting a couple minutes, the engine re-fires as if nothing is wrong so I scoot home and park it. Later, it again starts right up.

I'm thinking it's a fuel flow problem. I have experienced fuel flow issues with simple aircraft where the fuel vent is clogged - dirt daubbers in one fatal incident - and the fuel tank eventually reaches a vacuum point where it actually draws the fuel in the other direction, essentially starving the engine of petrol.

I'm unsure about the R65 fuel tank and any venting system. What about the Bing carbs? There must be some sort of ambient air venting to permit the fuel to continue flowing. My fuel cap has a second cork gasket added by a PO. The gaskets thickness prevents the cap from "centering up" when closed.

I have flushed out the tank and changed in-line fuel filters. I question the tank vent possibility because I do not see fuel filling the transparent filter body when I turn on the tap.

Here's another observation... Both Bings have had some sort of sealant placed on the very top of the carbs; on the circular 'whatever' at the high point of the carburetor body. How come this?

I've attempted to provide all odd-ball issues that I have found regarding the fuel issue. Any suggestions would be much appreciated. Doing a lengthy trip in two-miles relays is not my idea of fun.

Thanks mucho,   Monte

[DgM]

Oh oh, similar to my bike...ordering new coil, perhaps not the problem?  Did the tach stick in position or fall back to zero?  Talking to a local r65 owner, said the ignition module on his fouls up, the engine dies when warm, starts up after a few minutes.  Odd behavior.  To determine tank problems, can you ride (carefully) with cap loose to see if air can easily vent tank and pinpoint vent issue?

[montmil]

Oh oh, similar to my bike...ordering new coil, perhaps not the problem?  Did the tach stick in position or fall back to zero?  Talking to a local r65 owner, said the ignition module on his fouls up, the engine dies when warm, starts up after a few minutes.  Odd behavior.  To determine tank problems, can you ride (carefully) with cap loose to see if air can easily vent tank and pinpoint vent issue?

Recently installed a new Dyna coil to replace the OE Crack-O-Matic. First "2-mile and stall ride" was with no instruments but a Motoradd Elektrik GEN light bypass resistor installed. Second "2-miler" was with the new TrailTech Vapor digital gauge so when the engine died, revs went right to zero as the tach is tied into the coil/spark system.

Will try the loose fuel cap idea as this is my concern. What I failed to mention in the first post is that the tank cap may be the issue, because... Somewhere in the past, a PO had drilled out the tank key slot. I guess to remove the fuel cap. The fix involved filling the boogered up lock with epoxy. It's a smooth job but this and the double cork gaskets under the cap lead me to your suggestion... no tank venting = short time fuel flow.

Will give your suggestion a try but will simply circle the block for two miles+. That way, I won't have to push too far to get home.

Any other ideas, folks?  Thanks IA.   Monte

[montmil]

 To determine tank problems, can you ride (carefully) with cap loose to see if air can easily vent tank and pinpoint vent issue?

Well, d'oh!  Took a half turn off the sealed cap and rode off. Did a few miles around the block -the neighbors quit waving after the third pass- and the engine kept on keepin' on. Stopped once to take a look at the fuel filter and it had pushaline in it.  Here's a couple pics of the guilt one...

Ladies and gents, we have a winner! Thanks, DgM, I'll fax you a beer.


Note the drilled out key lock and the nice epoxy seal-up job.


And here's the twin cork gaskets installed, I'm guessing, to control tank slosh overflow during rides. Nice.

Going to call the guys, Mark and Marco at A&S tomorrow morning and try to score a decent used cap. BTW, both guys are named Mark, they just call one Marco to avoid two voices going, "Huh? I didn't do nothin'."

[Rob Valdez 79 R65]

My bike never had a cork gasket.  The old one that finally dried and broke into 4 pieces was rubber/plastic, and the new one that I installed was rubber/plastic as well.


Nasty looking cap there.  What does the inside of the tank look like?

[nhmaf]

So, did the PO also plug up the overfill drain tube with epoxy ?

Some people just shouldn't be allowed near machinery.

[montmil]

So, did the PO also plug up the overfill drain tube with epoxy? Some people just shouldn't be allowed near machinery.

Fortunately, no. He wasn't that bright. I agree with your sentiment 100%

RobValdez– Nasty looking cap there.  What does the inside of the tank look like?

Very tidy, thank you, Rob. I cleaned it out not long ago while replacing a fuel filter as I was chasing the stalling issue. So some good did come from this fuel cap issue. "If it ain't one thing..."   [smiley=wall.gif]

Thanks, guys!     Monte

[drewboid]

Glad you found your problem.
As to your question about the sealant on top of the carbs - this cures an air leak between the disk and the carb body, a typical problem. When the air leaks in the diaphragm will not raise the slide all the way. A similar problem occurs with a hole in the diaphragm. The bike runs out of power at cruise speeds. The last 1/3 of throttle movement does nothing.
ps - it took me a week to run down this problem on my R75/6.

[montmil]

Glad you found your problem. As to your question about the sealant on top of the carbs - this cures an air leak between the disk and the carb body, a typical problem.

Owe you an adult beverage, too. Check your fax machine!  [smiley=beerchug.gif]

[DgM]

That's one nasty looking gas cap.  Proof epoxy can lead to apoplexy...

[montmil]

Called up Marco at Re-Psycle BMW, in the Ohio heartland of the USofA, and scored a like-new fuel cap for the R65s current piece of junk.
http://re-psycle.com/
Ol' Marco said it's a virgin and he sure wouldn't pull a fella's leg... not at half price anyway. Still kinda pricey but at least the engine will keep on keepin' on.

Give these guys a shot when you need a part but don't feel like selling an organ... at least, an organ of your own.    [smiley=dizzy2.gif]