I have a 1994 XC125/Z Yamaha Riva Scooter. It will not start without Ether when it is cold. Once it warms up, it starts immediately. Once started, it runs fine, idles smoothly, operates well at both high and low speeds; has lots of power; and accelerates smoothly. I have rebuilt the carburetor, cleaned all the ports etc with carburetor cleaner, checked the adjustment of the float, exa,omed the condition of the gaskets, checked all hoses, etc. I believe the carb to be clean and free of varnish etc. Where do you think I should look for the problem? What solution(s) can you suggest?

SOURCE: Strange thigs about YAMAHA TW 125

Hi
I have been working on my carb today,the pipe from the bottom of the carb should just run down by the bottom of the swinging arm,there should be another pipe from the pipe on the left side of the carb just above the fuel intake which also runs down to the swinging arm and connect to nothing.
Cheers

SOURCE: took apart carb cleaned and now there is no mid or high range

did u install new gaskets, the engine might be sucking air from outside the carbs. u can use a propane torch (not light) spray a little around outside of the carbs, see if engine sounds different, if it does... leaky gasket.. u might check there is no unplugged vaccum hose.

SOURCE: 2001 yamaha ttr 250, starts, idles ok, bogs at acceleration

I have the same bike and same problem. Check the intake hose that connects the carb to the motor it may have a crack mine did and lost power when the bike warmed up. They don't make a replacement hose for it so I am using a rubber plumbers coupling with hose clamps. Might work? The hose is inch and a half diameter and about three inches long try that maybe. Good luck If it makes a chirping sound when the bike gets warm it's probably that hose sucking in air and screwingup your mixture.

SOURCE: Carburator problems- jets varnished up, runs on full choke only

Disassemble the carb and soak the entire carb in denatured alcohol. A bit of vibration will help to break up the varnish. The alcohol will eat the varnish in 15 minutes or so. Now finish with spray carb cleaner and an air hose. Concentrate on the pilot jet. Spray into every fuel circuit ( hole ) you can find.

SOURCE: Yamaha 2001 ttr 250. Bogs above half speed, under load

I have the same problems with my 1999 TTR 250, were you able to find out anything?

Walt
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