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J.R., Small Engine Technician
Category: Small Engine
Satisfied Customers: 7445
Experience:  Owner of outdoor power equipment business, repairing all makes and models.
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Need cardurator needle valve adjustments for Tecumseh HM100

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Need cardurator needle valve adjustments for Tecumseh HM100 10 HP year 2004 mounted on a Coleman Powermate 5000 generator please.
The initial adjustments are 1 1/2 turn open from lightly seated. Your engine may may a fixed high speed jet. If it has just a bolt head on the bottom of the bowl it has a fixed high speed main on it.
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Customer: replied 8 years ago.
My carb has an adjustable needle on the side next to the idle set screw, and an adjustable needle on the bottom of the float bowl. I had to replace the flow needle seat, float needle, and the float. Now it starts and then shuts right off. I need the adjustment for both needles please. I am a 30 year outboard marine tech and imagine....... I can't get this thing right.

The initial adjustments on the carb are as follows. The main jet in the bottom of the carb bowl should be set to 1 1/2 turn open from lightly seated. The idle needle on the side of the carb should be 1 turn open from lightly seated. This should get you started and running provided you have no other problems. The final adjustments are performed after the engine has reached operating temperature. Run the engine at full throttle and turn the main needle in until engine runs erratic and note position then turn out until engine runs erratic and note position. Turn the screw back in midway between the two points.

Return the engine to idle and repeat this process with the idle jet. If the engine hesitates when going from idle to full speed when accelerating quickly then adjust the main jet with engine under a load 1/8 a turn at a time until it accelerates smoothly.

Customer: replied 8 years ago.

That's exactly what I needed to know, sounds like the tech manual answer and I'm sure it will work if the carb doesn't have other problems.


Thank you very much my friend.

See attached link for an entire service manual for your engine.