Sears snow thrower with Chinese engine, surging then dies

fespo

Minister of Fire
Dec 14, 2005
720
South West burbs of Chicago
Im completely frustrated with this engine, I have tried everything I can think of. The snow blower is not mine and only used 1 TIME. They left gas in over the summer and messed everything up. A new carb was installed, opened up the jet, tried moving governor linkage around, new fuel line, clean in tank filter, new plug, only fresh gas, remove cap for vapor lock, Engine will start and run about 10 seconds then seconds then start surging with choke on then dies if you shut of choke . All gasket are in great shape, there is nothing I can see that is missing or broke. TIA Fespo
 

EatenByLimestone

Minister of Fire
Jul 12, 2006
7,263
Schenectady, NY
Try opening the choke.
 

coaly

Fisher Moderator
Staff member
Dec 22, 2007
3,723
NE PA
Float level too low, running lean when it dies? Does it run longer with half choke on? Or can you keep it running giving it some choke to give it more fuel?
With bowl off, carefully raise float until it stops. (closed needle and seat) The float is normally about level when closed.
 
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semipro

Minister of Fire
Jan 12, 2009
3,705
SW Virginia
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semipro

Minister of Fire
Jan 12, 2009
3,705
SW Virginia
Does this engine have a fuel pump of is it gravity fed?
 

EatenByLimestone

Minister of Fire
Jul 12, 2006
7,263
Schenectady, NY
I suspect that by "shut off" above @fespo means "disengaging" the choke, that is, opening the butterfly.
Probably, but it doesn't hurt to make sure.
 

semipro

Minister of Fire
Jan 12, 2009
3,705
SW Virginia
Nov 27, 2008
185
Upstate South Carolina
First thing I would do is a close inspection of the impulse line. It goes from the crankcase to the carb. If it has air leak or is not in good condition the engine well act exactly like you are describing.
 

nola mike

Minister of Fire
Sep 13, 2010
815
Richmond/Montross, Virginia
You said you moved the governor linkage around. If the spring isn't right or the linkage is off, it can flap back and forth and cause those symptoms as well. It's obvious if you look at the linkage when it's running though, as the throttle will be opening and closing, and eventually can close completely, killing the engine. But still sounds like a fuel delivery problem. I've also had DOA cheap replacement carbs.
 

fbelec

Minister of Fire
Nov 23, 2005
2,667
Massachusetts
make sure the mixture screw is at 1.5 turns out from bottomed out (all the way screwed in) then go from there. also when it dies quickly clamp the fuel line so that you can recheck the float level when it died out. if the fuel is filling the fuel bowl slow it might look ok when checked after a while but if it filling the bowl slow it might not be getting enough fuel to run.