5 start champ!

Yea, my bike is a 5 start champ. As in, it takes about 5 starts before she'll stay running. Start-stall, start-stall, start-stall... finally starts and stays running. Seems to be related to the temperature too. If it's warmer out, and the bike is cold, doesn't require as many starts. If the bike is warm, it will usually start right up.

And after the bike warms up a bit, it will race with the choke on. But, it stalls with the choke off at that point too. I can get it to idle ok, without choke, after I've been on it awhile. But sometimes it will still stall at idle w/o choke.

When I first got the bike, I took the carbs off and cleaned them very well. Has quite a bit of gummed up crap in there, and I did a carb rebuild kit on it too.

Ideas on where to start with this problem? Or maybe multiple problems?

 

This may or may not help your problem, but could be related....

My bikes been apart for years and finally got it together to running stage.

I've gone thru my carbs, started the bike, wouldn't idle unless choke was on, figured it was cold or out of tune. It would start without too much problem, idle depended on me watching the choke.

I made up some vacuum gauges to sync the carbs, and a makeshift fuel tank to supply fuel. Things were going pretty good and then the bike started to race. Hit the kill switch and started up again, idle was fine, start with the sync once again and motor would race once more.

Anyway I found out that if I held the bottom of the shaft that I was trying to sync the motor wouldn't race. I concluded the butterfly shaft seals were causing my grief.

Tore carbs off tonight and found the following.... (see pic)
dry, brittle, cracked shaft seals, allowing air to bypass the butterfly valve.

I'm not finnished with the seal replacement, I also need to find some orings for the fuel couplings. I will let you know if it fixed my problem.

 

Nick,

The fuel crossover o-rings are still available from Yamaha.
Part #: 3j3-14147-00-00

Nachoman