175 johnson pops back through carbs!!!

[ciscokid]

After running like a top for two days in catfish tournament ,I changed impeller,just like i have every two years for the past twenty years on this engine.we rebuilt the engine about three years ago and never had a problem with it untill now.I changed impeller and put it in my test tank,fired it up ran for mabe one minute,and BAMM!! stalled out.I restarted it and exact same thing.Any Ideas???

 

[dew2]

Carb may be too lean?open it 1/4 turn and try it.

 

[racerone]

Something ( debris ) stuck in a reed valve ????---------------Flywheel key sheared ????

 

[ciscokid]

Thanks guys,Ill check it out and let you know what happens!!

 

[haffiman37]

Check your thermostats, they may be stuck open.
New impeller and open thermostats will let the engine run at too low temperature.
The 'popping' is a sign of lean conditions. It might be temperature related, it might be carb related, it might be compression related, it might even be ignition related.