It's that time of year again and the lawn tractor wasn't running so well. Decided to rebuild the carb and fuel pump.

Motor is a 14hp Tecumseh OH140 single cylinder cast iron block. Carb is a walbro LMH, tractor is an 1984 Bolens XL medium frame, low hours in very clean condition.

I rebuilt the carb and fuel pump. Cleaned the carb, adjusted float to spec, replaced usual rebuild kit stuff. Adjusted manual choke and throttle linkage. No binding and all appears to be adjusted properly. Tractor idles well and throttles up smoothly.

When I move the throttle to full open before starting the tractor, the throttle shutter is wide open. After I start the motor, and lever to full throttle, the butterfly closes as if in low idle position, but it seems to be at full RPM as it should be. . Shouldn't the throttle butterfly be wide open at full throttle with the motor running? I don't understand how the motor can throttle up fine and yet the shutter is closed.

What am I missing here? Is this normal? I'm confused as the tractor is running fine.

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Question Authority before it Questions you.

The governor is controlling the throttle, just as it was meant to.

So what your saying is everything is fine? I suppose I don't understand how the govenor works.

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Question Authority before it Questions you.

The hand throttle sets the level of engine speed. As the load on the engine changes, the governor will modulate the throttle to maintain the engine speed set by the hand throttle.
It appears to me this part of your equipment is operating as intended by the maker.

The governer is sort of an old school rev limiter. It cuts off the air supply so the engine doesn't run away

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TC
Current stable:
- 2004 Mazda RALLYWANKEL
- 2007 Saturn sky redline
- 2004 Explorer...under surgery.

Past: 135i, GTI, 300E, 300SD, 300SD, Stealth

Thanks everyone, I get it now.

As a side note, I see that Tecumseh is out of buisness. What a shame to see another American manufacturer for many decades gone.

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Question Authority before it Questions you.

While Tecumseh made some decent engines in the past, their more recent stuff was a little lacking in the quality department. That, combined with the new EPA and CARB requirements has really taken it's toll on the whole small engine market, for some companies it's just not worth it to stick around.

The governor is more than just a rev limiter. It allows you to set the engine speed regardless of load (unless you overload the poor thing). It will open the throttle when the load increases, and shut it when the load lightens. So if you have little or no load on the engine the throttle will appear nearly closed when running, but wide open when the engine is stopped. If you think about it, that's OK - the governor is just trying to make the engine run faster!

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1984 300TD