# Tecumseh 10 hp Carburetor problems.



## backyard mech. (Sep 22, 2015)

Well with the first snowstorm of the season here, I got to try out my snowblower for the first time under working conditions. Well I'm having trouble with it running rough and also at times the idle just takes off running high? And it also seems to run better with the choke off? I still managed to clear the driveway, but not without a lot of swearing!! I bought this used unit about 3 months ago and have already rebuilt the carburetor, replaced the fuel lines...and done some other work like starter and stuff. Any ideas?


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## skutflut (Oct 16, 2015)

backyard mech. said:


> Well with the first snowstorm of the season here, I got to try out my snowblower for the first time under working conditions. Well I'm having trouble with it running rough and also at times the idle just takes off running high? And it also seems to run better with the choke off? I still managed to clear the driveway, but not without a lot of swearing!! I bought this used unit about 3 months ago and have already rebuilt the carburetor, replaced the fuel lines...and done some other work like starter and stuff. Any ideas?


Choke should be off when the engine is hot.


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## backyard mech. (Sep 22, 2015)

Ok, but this happened even right at starting it up cold. I couldn't have the choke on at all, guess that's good that it will start up cold with no choke. But it's still running very rough, and idle is all over the place...


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## HCBPH (Mar 8, 2011)

To me it sounds like one of about 3 possible issues. One is the carb isn't adjusted right, the governor is sticking or the linkage isn't right.

Here's what the linkage looks like on one I rebuild:


Make sure the governor arm on the front of the block is free to move. Another is if it's one of the non-adjustable jet carbs, hate those. I replace those with an Oregon unit with adjustable jets.

Good luck.


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## skutflut (Oct 16, 2015)

backyard mech. said:


> Ok, but this happened even right at starting it up cold. I couldn't have the choke on at all, guess that's good that it will start up cold with no choke. But it's still running very rough, and idle is all over the place...


I think there is some confusion about this choke on/off definition. Small engines rarely start cold without the choke being on. They start up somewhat ratty and smoky, and after a few seconds, you start moving the choke to off one click at a time until it is warm enough to run smoothly with the choke all the way OFF. 

If the butterfly valve is blocking the air intake of the carb, then the choke is ON, when it's turned sidesway, so you just see the edge of the butterfly valve, then the choke is off and not blocking aiflow thru the carb.

Any carb adjustments need to be done with the engine warm and the choke fully OFF.


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## Kiss4aFrog (Nov 3, 2013)

Is this Tec old enough it has an adjustment screw in the bottom of the bowl ??

It sounds like the carb is adjusted too rich presently.

Donyboy73 shows adjusting near the end of the video.


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## backyard mech. (Sep 22, 2015)

Yes this is the older carb style with the adjusting screw at the bottom of the bowl. As for the choke I'm sure i got the on/off switch right, but thats not my biggest problem. Its the idle running off on its own, and the sputtering. I just cant get it to run smooth, I also cant get the low and high idle balanced...im noticing to the high/low leaver dosent seem to adjust properly either. Im starting to think maybe theres something up with the linkage? It was all in very rough condition when i bought this unit. 
I never had a chance tonight to work on it as i was wiring in a new garage heater. Hope to work on it again tommorow.


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## bwright1818 (Dec 2, 2014)

Go to this link:

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

First, go to page 32, figure 27 and make sure your linkage is hooked up right and is all there. Then, go to page 27 and read how to determine if surging is because of the governor or something else. Also on this page is how to adjust the basic, not-running, adjustment between the governor and the carb.

If you find the carb is the problem and that you really CAN start the engine cold, with no choke, it would seem like your float valve might be leaking by. Re-check that the spring clip holding the valve to the float arm is not cocked and binding. To check if your float leaks by, with gas in the tank and the shut-off valve turned on (if there is one) the engine should be able to sit, not running, indefinitely, without a single drop of gas ever coming out of the carb. If gas leaks out when it's not running, there is a problem.

Hope this helps.


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## JJG723 (Mar 7, 2015)

Check to see if the shaft for the throttle plate is worn causing the butterfly to stick. I've run into this issue a few times.


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