Simplicity 922EXD Backfires and Loses Power Under Load

[bk10s]

My Father-In-Law's single stage snowblower (Engine 12D105-0010-F8) starts on one pull and runs great with very slight choke. Normally, my brother-in-law runs the machine. Last weekend I used it. When engaging the auger the machine will backfire and lose power momentarily. Same thing happens when you start blowing snow. Think this is a carb issue, or something more serious?

 

[Rivets]

If it came into the shop with these symptoms, I would be looking at a lean run condition. I suspect that the float bowl is not filling with the normal amount of fuel. I would be cleaning and rebuilding the carb, replacing the float, float needle and float seat, plus bowl gasket.

 

[bk10s]

Thanks Rivets. I will start with the carb, as you suggest, and report back.

 

[bertsmobile1]

Don't do snow blowers here but to add to what Rivets already said
Those symptoms can also indicate water in fuel or a leaking head gasket.
Water will be obvious when you clean the carb
To check for blown gasket, run the engine for 5 minutes then shut down.
Count to 10 then pull the dipstick.
If smoke rises out of the tube then the casket is on it's way out.

 

[bk10s]

Great News - I think it was a combination of dirty carb and old/bad gas. Cleaned things out and it runs like a champ! Thanks to Rivets and bertsmobile1!!