I Have the G1 running! Sort of

[dcolliau]

Ok gang how bout some input. New jug, cylinder, piston, rings, crank case seals. 1986 Yamaha G1
It will run when choked or by dribbling fuel in the carb. We had the carb off and my nephew said it was clear. I unhooked the muffler same thing. I am thinking fuel pump. It has more fuel coming out than before the rebuild but I wouldn't call it a lot. I have searched but I have not found any info on fuel flow.
Let me know what ya think.
Thanks,
Don

[sho305]

Are the reeds working right? Any leaks in the intake area or cylinder/etc. The pump usually gushes in spurts, it should fill the carb bowl in a short time, way more than it could ever burn....if you have the hose off where it comes into the carb, and that is on the starter not running. You could spin the starter with the carb bowl off and it should be enough to fill the bowl in what, maybe 20 sec or whatever. Way more than it would ever need even full throttle. There would have to be nearly nothing coming out of the hose at the carb for it not to run. Even then it would run until the bowl were empty....so I think the problem is elsewhere, or fuel restriction is in the carb, long as you are filling the bowl on carb.

[JohnFl]

Originally Posted by dcolliau

Ok gang how bout some input. New jug, cylinder, piston, rings, crank case seals. 1986 Yamaha G1
It will run when choked or by dribbling fuel in the carb. We had the carb off and my nephew said it was clear. I unhooked the muffler same thing. I am thinking fuel pump. It has more fuel coming out than before the rebuild but I wouldn't call it a lot. I have searched but I have not found any info on fuel flow.
Let me know what ya think.
Thanks,
Don

I'm having the same problem with mine. I have an electric pump on it and I know it's pumping enough but it doesn't like to run smooth unless I give it about 1/2 choke. Then it runs nice. Carb is nice and clean, I use welding torch tip cleaners to be sure the passages are all spiffy. I cleaned the plug, it looked good anyway. Put in fresh fuel, made sure the vacuum hole to the old fuel pump was plugged. Brand new used reeds and cage.
The electric pump is a low pressure pulse pump and it's not overpowering the float needle.
What's the float level supposed to be set at? Mine is level, parallel with the body with the carb inverted. Just seems to be lean.

Any other places I could have a vacuum leak maybe?

Ideas???

JohnF
Phoenix

[sho305]

I would look for a vacuum leak first, or spray the intake area while running, etc. Any leak between the carb and spark plug could do it, sometimes before the carb as that makes them lean too but they usually still run poorly.

[dcolliau]

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http://www.buggiesgonewild.com/gas-y...tml#post804128