Ht 75

[mlk]

I have a Stihl HT 75 with non-adjustable carburetor - no high or low mix screws. It runs best with the idle screw 1-1/2 turns clockwise from seated, but still has some hesitation when it accelerates. I was thinking of replacing the carb with one with individually adjustable high and low mix screws. I've never used an HT 75 other than mine, but I was wondering if the long shaft may create enough inertia to be responsible for the hesitation. Is it unrealistic to expect a pole saw to accelerate like a regular chainsaw? Anyway, would the Stihl 4137 120 0606 be the correct carb to switch to?

 

[sedanman]

The ht-75 uses the 4137 series powerhead, the carb you mentioned works well in this powerhead. You are correct about the shaft adding to the lead on the engine. No your polesaw will not accellerate like a chainsaw. You may have to trim your shroud a little to use that carb.

 

[stihltech]

HT75

There is a lot less motor turning a whole lot more than a chainsaw. The shaft will only take so much torque also.

I know I stand up for the fixed jet carbs, but if this one gives you any trouble, replace it with the adjustable. It REALLY hates to sit with old fuel or the slightest amount of moisture in it.
The passages are very small and plug easily.

 

[NevadaWalrus]

Stihltech, most of the newest Stihl products have gone back to a semi adjustable carb. Haven't checked but wouldn't a carb from a current unit work good, be somewhat adjustable and do so without voiding emission regs?

 

[stihltech]

75 carb

Yes, the newest models have an adjustable carb. I would definitly get one for this machine.