# Tecumseh HS40-55265C carb governor adj - check my future work pls



## tlshawks (Feb 9, 2018)

Howdy again, new project.

I have the subject line engine on an Ariens 1971 922002. I acquired it yesterday, and noticed that aside from a known idle issue, it seems to be set with an extremely high peak RPM and would die immediately when I had it revving with the auger and wheels engaged. 

So, today, I rebuilt the carb, new fuel line, etc. I left the governor setup as is knowing I would probably get to that last in the process. The fixes started out rough. Wouldn't idle for crap, wouldn't also hit near the peak RPM...it quite simply was missing and tough to find a sweet spot in any way. I checked my idle mixture and main mixture turns, then noticed the governor was looking, simply put in a typewriter key, as an "(". That's exaggerated obviously, but in the image you'll understand what I mean.

As one can see in the images attached, it's a 2 part governor arm but there is no high speed screw to turn, only an idle "crack screw". The arm has a single hole at the top of the top arm that the throttle arm attaches to, 3 holes midway down that the I assume it's a tension spring attaches to, then a set screw and the bottom that when loosened, the top arm can be adjusted that then attaches to the governor gear assembly inside the block.

From videos on Youtube, the general way the adjustments can work is if you lean the top arm right of center with the bottom arm, this advances RPM's (which was how it was originally). Lean it left of center, it retards high RPM.

So...I straightened it out, and my low speed RPM's dialed in near perfect, no more dying when loaded. High speed is still way way too high. I've seen and heard enough video of HS40's to know just from the sound, way too high.

So, my questions are, considering I ran out of daylight and reasonable temps (hands are froze)...

1) I take it if I adjust it to more of an ")" - top arm pivoted to the left to a varying degree of trial and error - this should in some fashion tame the high RPM's.

2) will this also affect idle speed?

3) Since I don't have a tach (yet), I have to eyeball all this, also going by sound. The Tecumseh service manual seems to indicate that WOT is more or less with the throttle shutter at what I'd term not straight on wide open when looking at it. It should only open roughly 70 degrees. When looking down the carb throat, it's not straight up and down "thin", but maybe if one could look at it standing above it it would be at somewhat like 1 and 7 o'clock across the opening.

The pics are from the left side, center, and right side of how it looks right now, AFTER I lined up the top and bottom pieces of the gov arm and it started running much better.



I've got a tach coming but it ain't gonna be here until this weekend most likely. Otherwise, I just want to know if I'm thinking all this through correct. I've rebuilt probably 50 small engine carbs in my lifetime, but I've never had to mess with a governor before. I'm suspecting it got out of whack because the PO tried to squeeze more RPM's out of the machine to take on deeper snow while the carb really only needed a rebuild - and now that I rebuilt it, it more or less at first made things worse.


Thanks for any help/hints!


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## paulm12 (May 22, 2015)

I can't directly answer your question, but here is the governor arm setup on my HS40 off of a 1980 Toro that I just worked on. It appears similar. 
.


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## tlshawks (Feb 9, 2018)

That does help, really does. Yours is how I understand it has to be. Slightly pivoted to the left on the gov arm. Yours has a high speed RPM adjustment screw and a gas primer but otherwise looks very similar.


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## Slamman60 (Feb 17, 2020)

How's your Ariens running? I just acquired a model 922002 as well and am having trouble getting it to idle with the choke off. Mine had bad fuel so I replaced fuel lines, cleaned tank, and cleaned out the carb. First time messing with small engines and owning a thrower. You mentioned watching videos and reading manuals on our model. Any chance you could send those my way?


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## rod330 (Oct 9, 2015)

There are lots of great reference links in the sticky section above. Here's where to start for your HS40; governor section begins on page 26.

http://www.barrettsmallengine.com/manual/tecumsehlheadmanual.pdf


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## rod330 (Oct 9, 2015)

Skip to the 5:30 mark on this video:






Skip to 3:00 mark on this video:


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