yamaha qt50 stalling/ no decelerating

Hi, I just fixed up my 1980 Yamaha qt50: new air filter, new spark plug, rebuilt carbutetor. I got it running, but it stalls after I've been riding it for a few minutes. I can get it to top speed, but then it won't decelerate when I let off the throttle. The stalling doesn't seem to be related to the lack of deceleration.

Re: yamaha qt50 stalling/ no decelerating

Clean your cockpit screen , watch it ,, it's so little, and ajust the throttle screw.

Re: yamaha qt50 stalling/ no decelerating

Peter Frank /

I need help quick, I'm trying to crash my school's lame Homecoming Parade.

1. What and where is the cockpit screen?

2. I adjusted the throttle screw, which slowed my idle, fixing the deceleration problem.

3. It won't start up again after it's been running enough to get really warmed up. It will start again after it's cooled down ~1hour. I replaced the ignition coil, but the problem persists.

4. It's still stalling after I've been riding for about 20 minutes, never fails. I've been pushing this moped all over town.

Re: yamaha qt50 stalling/ no decelerating

No help for the wicked!

Re: yamaha qt50 stalling/ no decelerating

condenser. Replace it if it has one.

Re: yamaha qt50 stalling/ no decelerating

Peter Frank /

I think I've figured out my problem. The carb seems to be flooding, which is getting the spark plug wet causing it to stall and then it will only restart when the engine has cooled down and the plug has dried. My float must not be floating, so I'll take it apart and clean it.

If anyone has any good ideas on how to keep the float from sticking besides just using carb cleaner, I'm all ears.

Thanks

Re: yamaha qt50 stalling/ no decelerating

to test the float do this

take the float out of the carb

fill a bucket of water (or ur sink) with water

Drop the float in

Push the float to the bottome of the water

See if it floats back up

some floats get holes in them, and will take the gas in, and not allow it to float

nick

Re: yamaha qt50 stalling/ no decelerating

Ben Elsewhere /

I agree that it is probably a bad float. Hook yourself up with a carb rebuild kit. it's super easy to go about rebuilding a carb, and it shouid include a new float, and all the other goodies you need.

Re: yamaha qt50 stalling/ no decelerating

Peter Frank /

Well my float is floating just fine, I put it under water and there were no air bubbles and it floats just fine. The carb is super clean and the float valve moves freely. Now I'm really confused, I was sure this was the problem.

Re: yamaha qt50 stalling/ no decelerating

That doesn't mean the floa arm isn't/wasn't sticking for some reason.

Re: yamaha qt50 stalling/ no decelerating

hey. i have the same bike, i have had the same problem. i did all you did. here was my solution. my throttle cable needed cleaning and relubing it stuck try using liquid wrench dry lubewith PFTE (Home Depot $7). however when i tried it with the newly lubed cable it still stuck...$%*&!!! The throttle is indirectly linked with the automatic oil mixer on top of the case. this will get gummed with crap... clean it and lube it's cable too This may solve your woes. SMooTHE SAIling KId!

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