1541 governor issue

weedhopr · #1 10-28-2018, 07:11 PM

I have a 1991 CC 1541 with the Kohler Command 15 engine.
I haven't had any issues till recently. The last few times I used the tractor, everything works as it should till the engine warms up. After it's warmed up, the engine races when there is no load. (tractor is stopped, mower not operating) I have a Tiny Tach hooked up to it, and when I'm mowing, at full throttle, the engine is running at just under 3600 rpm. It used to remain around 3600 when I turned off the mower. I first noticed it while picking up brush in my yard. I had the tractor stopped, running about 1/4 throttle ( around 2000 rpm) All of a sudden, the engine started to race, and I noticed when I pulled the throttle to idle, it had increased to around 5000 rpm. Idle, no load is around 3800 after it's warmed up. It did the same thing again this afternoon while cleaning up the garden, and again while mowing. As soon as I shut off the mower, the rpm increased to over 4000 rpm unless the tractor was moving, or the mower was engaged. I looked at the throttle and governor linkages, and don't see anything wrong externally.
What would cause this issue?
thanks much,
Mike Schweim

CubDieselFan · #2 10-28-2018, 07:34 PM

The 1541 should have a Magnum engine. Sound like the governor gear or something related to the governor. I think you can look down in the oil fill hole and see the gear. Sam Mac has a engine In the for sale section.

ol'George · #3 10-28-2018, 08:25 PM

Quote:

Originally Posted by weedhopr

I have a 1991 CC 1541 with the Kohler Command 15 engine.
I haven't had any issues till recently. The last few times I used the tractor, everything works as it should till the engine warms up. After it's warmed up, the engine races when there is no load. (tractor is stopped, mower not operating) I have a Tiny Tach hooked up to it, and when I'm mowing, at full throttle, the engine is running at just under 3600 rpm. It used to remain around 3600 when I turned off the mower. I first noticed it while picking up brush in my yard. I had the tractor stopped, running about 1/4 throttle ( around 2000 rpm) All of a sudden, the engine started to race, and I noticed when I pulled the throttle to idle, it had increased to around 5000 rpm. Idle, no load is around 3800 after it's warmed up. It did the same thing again this afternoon while cleaning up the garden, and again while mowing. As soon as I shut off the mower, the rpm increased to over 4000 rpm unless the tractor was moving, or the mower was engaged. I looked at the throttle and governor linkages, and don't see anything wrong externally.
What would cause this issue?
thanks much,
Mike Schweim

I'm confused,
you say it has a Kohler command engine.
Cub says it has a M-15 magnum engine (same as an M-18) not a command style.
if it indeed has a command engine, it is been converted.
I do agree it has a governor problem that needs to be adjusted or replaced.
If it is the original mag engine, I suggest you follow the procedure in the service manual (Available free here in our tech section)

weedhopr · #4 10-30-2018, 11:21 PM

It is the Magnum 15 engine. I remembered wrong.
I haven't had a chance to look into it yet. I have the manual downloaded on my computer. Nothing has been done to the engine prior to the governor issue. Just started all of a sudden while the tractor was parked, with the engine at about 1/2 throttle.
I used the tractor last weekend, and it worked normally till it warmed up, then it started to race when it was running with no load.

Gompers · #5 10-31-2018, 12:46 AM

There isn’t a hole where the governor stub shaft would be is there? It’s a known problem on these engines that the governor stub shaft can back out and drop into the engine. When that happens it’s usually game over for the engine. But if it’s doing ok on the governor sometimes, that suggests a different problem.

Try adjusting the governor and inspect the springs and linkages to make sure nothing is binding.

ol'George · #6 10-31-2018, 08:54 AM

Quote:

Originally Posted by Gompers

There isn’t a hole where the governor stub shaft would be is there? It’s a known problem on these engines that the governor stub shaft can back out and drop into the engine. When that happens it’s usually game over for the engine. But if it’s doing ok on the governor sometimes, that suggests a different problem.

Try adjusting the governor and inspect the springs and linkages to make sure nothing is binding.

If the gov. stub shaft fell into the engine, it would be squirting oil like the preparatory cleansing for a colonoscopy

ol'George · #7 10-31-2018, 09:07 AM

I would follow post #2 to visually see if the gov gear is still ok, as
if it has dropped off or broken, it is very strongly recommended to not run the engine as it can cause catastrophic internal damage.
It does not happen often, but it is not unheard of.
If the gear appears ok, them usually an adjustment or linkage needs attention.

weedhopr · #8 11-17-2018, 09:54 PM

I unscrewed the oil filler neck, and looked in today. The governor gear is still there, and turns with the engine. I rotated the crankshaft, and there are no missing or damaged teeth. Held rpm at 3240 rpm today at full throttle, no load. I didn't run it enough to get it to normal temps, just enough to move the tractor to the stall in my garage where I could remove the mower deck. and back to its parking space after removing the deck.
The governor hasn't acted up until the engine got warmed up.
Mike

ol'George · #9 11-18-2018, 09:52 AM

Ok the engine needs to run @ 3600 as it is rated at full throttle.
Adjust as per service manual.
Either your throttle-to-gov is not adjusted properly,( not pulling far enough)
or your gov is not adjusted properly to the carb.

weedhopr · #10 07-11-2020, 06:55 PM

Hadn't had any issues since my last post..but....
Yesterday while mowing the yard, the same thing happened again. All was OK, running full throttle at 3600 rpm. I got almost done mowing my yard when it suddenly started racing when I got to where I had already mowed. I had to throttle back about 1/2 way every time I turned around, and increase the throttle again when I got back in the taller grass. When I parked the tractor in my garage again, it was running at 2800 rpm with the throttle all the way back to idle.
I tried again today, and everything was back to normal. Around 1000 rpm at idle, 3550 at full throttle, mower engaged or not engaged.
Governor linkage is still correctly adjusted per the manual, and everything moves free.
Is there something in the governor that would disengage, or loosen up after the engine got hot?
thanks,
Mike