3700 rpm !!

B

Bmwz3coupe

Member
I have a fresh roadside pickup self-propelled that has a 3700 rpm that I cannot change. Bending the govnor throttle spring tab does not change the rpms hardly at all. I removed all the metal covers to clean the area where the governor goes inside the case but nothing changed. Ideas o wise ones? 126M02-1525-F1. 1/2014 mfg
 
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I have a thought that inside the governor has failed. It can be replaced but it’s a bit of work with usual new gaskets.
Are you willing to do it?
 
I want to say that you gently use a 3/16" socket on the top of the governor shaft and lightly hold it while the nut is loosened and tightened. Then see what the RPM is. If it doesn't change then the governor is bad. If so, $23 for the part new plus you will need the sump gasket $6.

https://shop.briggsandstratton.com/pages/parts-lookup#/Briggs_&_Stratton/126M02-1525-F1/Camshaft,_Crankshaft,_Cylinder,_Engine_Sump,_Lubrication,_Pistion_Group,_Valves/126M021525F1/103320002C/y

Sump gasket is #12 on Camshaft, Crankshaft, Cylinder, Engine Sump page. Oil slinger governor is part #43 on the same page.

If you can refrain from taking other things on it apart, and not tweak things like the spring just to see if it helps - you might get it done in an hour or so. It is not a hard job as long as you don't mess with other parts on it.

Then you can sell it for a small profit or give to someone in the family who needs one. It could also be that the governor has slipped and just needs adjustment. Also an easy job. :) The engine runs at full speed all the time, the governor pulls it back to operating speed. If it is a mower that is usually around 3100 - 3200 RPM.

You will need oil too.
 
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Hello B.,

Whoa! What to say this is not a fixed RPM engine design intended for this mower? 3700 RPM is not what I would consider a bad governor or a "runaway" RPM.

What mower chassis make, and model is this engine on? Does it have an actual throttle cable?

How are you measuring RPM? Some testers are just not truthful and can mislead you.

Being how it was a salvage find; this could be a case of a prior DIY owner tinkering with the governor adjustment or linkages. They could not figure it out, so it went to the road front

It's easy to go down "rabbit holes" with equipment when you do not have any history about it.

Put aside the speed dial and credit card part purchase solution until you learn how the governor works and if the linkage is jammed or stuck for the carburetor.

I would not tear into this without a little more study, both online and in the service manual.
 
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I found the problem everyone. I removed the carb and discovered the throttle butterfly blade had some how come slightly loose and jammed in the throat of the carb. That severely limited the ability of the throttle to move via the governor. Thank you all for suggestions.
 
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