Small Engines (Lawn Mowers, etc.): snowblower, precise calibration, orfice

Question
Hey,i have a Tecumseh snow-blower. It starts and runs but surges. It has a small pin hole in the float. So i was curious to what causes the engine to surge off and on, if it was the pin hole or maybe if it needs a new governor spring? Hope you have some suggestions, thanks

Answer
99.9% of surging is caused by a dirty or mis-adjusted carb.  It is very rare for a governor spring to cause surging.

Tecumseh carbs are calibrated very precisely from the factory, especially the fixed jet carbs which is the majority of Tecumseh carbs.  Emmision standards is the primary reason for the precise calibration.  It takes very little debris to partially block a carb orfice/passage which causes the carb to malfuction.

I would replace the float and while you have the carb disassembled blow compressed air, from an air compressor, through all the orfices.  Reinstall carb and test.  I have had to clean some carbs 2-3 times before to get them running properly.

The link below covers Tecumseh engine repair:

www.cpdonline.com/692509.pdf

You can also find Tecumseh carb manuals online.

Clean the carb with compressed air and let me know if it runs any better.
Eric