Keeps racing...Briggs 126M02-1479-F1

[dart451]

Got a high wheel trimmer from a customer. The engine keeps racing even with the throttle closed. He says he lent the trimmer to a neighbor and when it was returned, it started doing this. So, I can hold the governor spring and it slows down but it should be noted that nothing seems to be altered! Normally, I can stretch the spring a little and it runs slower but it doesn't seem to be happening this time. I guess the next step is to re-adjust the governor but I can tell the cowling has not been off the machine. Any suggestions here?

[bgsengine]

replace that governor spring first of all, anything else is a moot point until you got the correct spring. never stretch spring to adjust , use the bendable control lever (that spring hooks into) to adjust RPM.

[KE4AVB]

With the condition of the spring it shouldn't be operating anywhere near full speed it governor is adjusted and operating properly.

Hopefully Dart that you understand that the governor spring pulls the throttle vane to wide open while the governor pushes the throttle vane close and it is a delicate balance between to two governs the engine speed. While the engine is running push the throttle vane lever towards wide open if the governor is adjusted and operating properly it will push back to slow the engine down. If you don't feel the push then try a static governor adjustment. If still acting up after the adjustment then governor has failed and maybe even the oil slinger itself.

BTW stretching the spring will slow; unless, you are shorting it thus increasing its spring rate.

[dart451]

The governor spring is my making and yes, I should be ashamed of myself! I won't do this again! I always forget about the tangs! Anyways, I will try to adjust the static governor, see if that improves anything. The spring was perfectly ok till I messed with it! How often does a governor fail?

[KE4AVB]

I don't the answer to that one.But Murphy tends visit me every once a while and I seen very things to happen.

[dart451]

Anyone know what fails with the governor inside the engine?

[bgsengine]

Anyone know what fails with the governor inside the engine?

governor gear flyweights can blow apart if engine is overspeeding, nylon governor gear can crack and break in half, melt in an overheat, or harden up (too much heat) and break into pieces, broken piece of anything getting into engine can jam gear and break it, governor spool shaft can brek off, slinger type governor gears, riveted hub can wear away or vibrate loose and break off, governor arm can get damaged, just to name a bunch of things off the top of my head. In short, it is fairly rare except on an abused or mis-adjusted engine, but not uncommon. KE4AVB makes a solid point- make sure governor will actually attempt to close the throttle - unhook the spring , make sure the throttle moves freely open to closed, then leave it open with spring off, see if the governor will close throttle (can always stick a small piece of wood in place with a dab of grease to hold throttle slightly open) if it won't then try again after a static adjustment, if it still won't then it's time to crack engine apart, but odds are if you have to go that far, it isn't gonna be worth it. If throttle won't move freely then governor isnt gonna do anything , you gotta find what's binding first.. if governor does close throttle (probably will stall out) then just maybe a new spring is all that's needed. - despite your stretching of the spring ,it looks a bit mangled, and may have been broken off and re-worked to hook back up (but that creates way too much spring tension) which is why I suggested replacing spring first, but if governor won't even try to close throttle, then it's pointless to bother with spring until the governor's figured out.

[dart451]

I did try this and the governor does control the engine...it will slow down...and I believe stall if I don't hold the throttle open a little...I ordered a new spring...

[dart451]

Ok, I checked static governor setting and it was correct. I ran it without the spring and it does idle down and runs...gonna wait for the new spring, see where I am at that point...