s219
Super Member
- Joined
- Dec 7, 2011
- Messages
- 8,608
- Location
- Virginia USA
- Tractor
- Kubota L3200, Deere X380, Kubota RTV-X
I have an old 2002 Deere LT-150 mower that I no longer use for mowing, but have kept around for odd jobs. I have been thinking of selling it just to free up some space in my barn and hopefully someone else can put it to better use. It has a Kohler CV-15 single cylinder engine. Last fall it started running lousy and surging, then I couldn't get it to start a few weeks ago. I planned to clean and rebuild the carb, but found a brand new carb for $5 more than a rebuilt kit, and installed that yesterday. Got it started and it runs great but still surges.
I did some troubleshooting and it seems to be a problem with the governor. At higher speeds, I can see the governor throttle linkage going back and forth as the engine surges. If I hold the linkage steady with a finger, there is no surging and the engine is smooth. So that suggests to me that the surging is not due to a fuel/load problem that is being corrected by the governor, but is instead being caused by the governor itself.
I made adjustments to the governor as instructed in the Kohler service manual, and played with the spring setting, but all that does is change the response time and behavior -- doesn't get rid of the surging. So I'm left to thinking that there is an issue with the governor mechanism internal to the engine. Based on the service manual, it looks like a nylon or plastic gear was used for the governor (running off the crank) which then spins some weights that will go up/down and move a follower arm that goes through the block and out to the throttle linkage on the carb. Here's a pic from the service manual:
I am guessing that maybe the gear is worn or skipping periodically, or maybe there's an issue with the weights. But the surging is very smooth and seems to only happen at higher RPMs, and I don't think that would be happening if something was straight out broken.
I'm wondering if anyone else has dealt with this before and has any insight. The mower is probably not worth more than $250 or so. I don't think it will be worth the trouble to tear the engine apart to replace the governor parts. The thought crossed my mind that I could loosen the throttle linkage so that it's not affected by the governor, and that would probably be OK for basic use, but I don't want to sell it that way. I doubt it would behave well for mowing without a governor.
I did some troubleshooting and it seems to be a problem with the governor. At higher speeds, I can see the governor throttle linkage going back and forth as the engine surges. If I hold the linkage steady with a finger, there is no surging and the engine is smooth. So that suggests to me that the surging is not due to a fuel/load problem that is being corrected by the governor, but is instead being caused by the governor itself.
I made adjustments to the governor as instructed in the Kohler service manual, and played with the spring setting, but all that does is change the response time and behavior -- doesn't get rid of the surging. So I'm left to thinking that there is an issue with the governor mechanism internal to the engine. Based on the service manual, it looks like a nylon or plastic gear was used for the governor (running off the crank) which then spins some weights that will go up/down and move a follower arm that goes through the block and out to the throttle linkage on the carb. Here's a pic from the service manual:
I am guessing that maybe the gear is worn or skipping periodically, or maybe there's an issue with the weights. But the surging is very smooth and seems to only happen at higher RPMs, and I don't think that would be happening if something was straight out broken.
I'm wondering if anyone else has dealt with this before and has any insight. The mower is probably not worth more than $250 or so. I don't think it will be worth the trouble to tear the engine apart to replace the governor parts. The thought crossed my mind that I could loosen the throttle linkage so that it's not affected by the governor, and that would probably be OK for basic use, but I don't want to sell it that way. I doubt it would behave well for mowing without a governor.