Small Engines (Lawn Mowers, etc.): Carb for snowblower, internal passages, adjustment screws

Question
Ok, got an old airens snowbloewer, about 5 horse tecumse.

It starts and runs well cold, but after it warms up, the engine races up and down.  We have fiddled with the mix screws, but it didn't help much.  What else could we look at?  I am hoping to not buy a new carb

Jeff


Answer
If it only runs properly with full or partial choke and the mixture screws make no difference, there is a blockage inside the carb.  You will need to thoroughly clean it using a piece of tag wire to push through all of the internal passages and follow up with aerosol carb cleaner.  The mixture adjustment screws should have an initial setting of 1 1/2 turns out from lightly seated.  Hope this helps.