Qdude wrote:
I thought that I had problems with the mixture leaning out at high revs. Someone suggested that I had a fuel flow problem instead. They were right.
You have an old bike. . .
I remembered something from a bike I had years ago. Maybe you have gotten the problem fixed by now.
Sometimes the vent inside of the gas cap gets blocked from contamination. If that happens, fuel gets vacuum locked inside of the tank, preventing it from flowing correctly.
The bike was a Suzuki TS-185 in otherwise pristine condition. It had been at the shop for a stalling condition. It would run for about 10 minutes, and then shut off. The mechanic thought it was the coil, and then when that didn't fix the problem, he thought it was the CDI box or magneto trigger, which the owner didn't want to buy, so there the bike sat, with a repair bill still outstanding and an unresolved repair issue.
Of course, I got the bike for cheap from the owner, who didn't want to spend anything on it, and for the cost of the outstanding mechanic's lien. Somewhere along the line the lacquer on the magneto trigger was damaged before I got it, so I had to fix that and because that wasn't the problem, the bike would still shut off.
While dealing with this issue, I was cruising down the road at about 35 mph when it shut off, like someone had turned off the key. I popped the gas cap and the bike roared back to activity. Cheap fix.
When he found out I got the bike fixed, the shop owner called me a dog, and accused me of being a thief, but I just smiled, because I figured he was already wrong about other things, what was one more?
I used a piece of broken guitar string to poke out the rust in the vent hole. Being an occasional musician provides a great source of different gauge wires. It can provide hours of entertainment.