Fuel petcock

[Anonymous]

When the fuel petcock is in the ON position and the bike is let idle for a few minutes, it begins to starve for fuel, but this problem seems to be absent when it runs at higher RPM's. Is this something normal or is the diaphram beginning to pack it in?
Thanks,
-Morgan

[Anonymous]

Re: Fuel petcock

When the fuel petcock is in the ON position and the bike is let idle for a few minutes, it begins to starve for fuel, but this problem seems to be absent when it runs at higher RPM's. Is this something normal or is the diaphram beginning to pack it in?
Thanks,
-Morgan

Im curious to know how you know its starving for fuel??

[Anonymous]

re: how I know

Pretty simple actually, the engine died. Actually, I came to the conclusion when after it slowed and stalled out I noticed that the fuel filter was empty (brand new filter so it wasn't just plugged). From that I concluded that it couldn't be the carbs. I had just cleaned the petcock screen, and it does run fine on prime, so it's not just rust in the tank blocking the screen. I actually wired the vacuum line to eliminate the possibility that it might be sucking air since it is an old fairly stiff hose. So, it leaves me thinking it's the petcock itself.

-Morgan

[Anonymous]

im seem to be having the same problem
even flushed the tank out on two occassions but seems fine on prime
postion 8O lets us know if ya find any more out.

[Jay B]

Seems to me that either you've got a hole you missed in the vacuum line or the diaphram spring is going bad.

[Anonymous]

I agree, sounds like a vacuum problem. That's what it was on my 1100 when I cleaned the tank and petcock.
GY

[Anonymous]

update

Well, I fiddled about with the lines a bit more, found nothing, and continued to have the same problem, only this time the number one cylinder wasn't firing. There was a good spark and plenty of fuel in the bowl (when it was run on prime). So off came the carbs to clean the jets. They turned out to be fine, but when I got the carbs off I noticed that the (upper) connecting nipple between #1 and #2 was very loose. If it was drawing air I imagine that it could potentially cause both problems. I won't find out for sure until I can get back up to my parents where the bike is stored, which won't be until Feburary (Maybe not even then, since the bike is under a tarp on the back deck and lord only knows what the weather will be like).

Morgan