Hi guys

I have a problem with a new YS 91.

When i open the throttle above half it seems that the fuel that is coming from the tank is stopping and when i forward the throttle even more it sucks the fuel from the carb and get it back to the tank...odd!!??.

Also some full is leaking from the throttle drum where the throttle arm is located.

What is wrong with that engine!?


Thanks,

Adi

Its one of three things most likely:

1: You may have your lines reversed. A YS doesnt actually pump the fuel, but pressurizes the fuel tank and uses positive pressure to push the fuel to the carb.
2: The pump diaphram might be bad. This also could be a function of a bad diaphram within the pump. Has the engine sat around for a period of time?
3: Lastly, and most likely, check and make sure sure that your check valve on your tank vent line to your pump fitting on the engine is going the right way. If its not, youll just be pressurizing the line, and the engine will draw what fuel it can from the tank, creating a vaccuum, then when you pull the throttle back, the vaccum draws the fuel back into the tank. This is the most common problem I see when someone starts running YS motors. Its a very easy mistake to get that check valve backwards.

Go Tank with the YS info!!!

What Tank said

Thanks guys

I will check that

Adi

Thanks guys

I will check that

Adi