Older craftsman GT 5000 with 22HP B/S that’s back firing and won’t rev.up

[suppraman]

Starts back firing and won’t rev-up, puffing black exhaust . I’ve cleaned carb. Disconnected coil diodes , gaped coils, checked valves.ect. The weird thing is when I move the ignition key to the off position it runs fine. But there’s no PTO ,not charging the battery ect. So what could it be ??? What’s getting turned off??

 

[ILENGINE]

I suspect that the float valve is not sealing allowing overfilling of the carb. When you turn off the key it is killing the fuel solenoid on the carb preventing extra fuel from being drawn into the main jet of the carb. or the main jets fell out when you took the carb apart.

item 117 or 117a in this diagram https://www.partstree.com/models/44...-engine/carburetor-kit-carburetor-overhaul-3/

 

[suppraman]

I suspect that the float valve is not sealing allowing overfilling of the carb. When you turn off the key it is killing the fuel solenoid on the carb preventing extra fuel from being drawn into the main jet of the carb. or the main jets fell out when you took the carb apart.

item 117 or 117a in this diagram https://www.partstree.com/models/44...-engine/carburetor-kit-carburetor-overhaul-3/

The carbs coming off tomorrow .thanks for your advice.

 

[Auto Doc's]

Hi suppraman,

I concur with the float and needle/seat being suspect.