88 Gas DS - sudden, temporary power loss

[Toddyus]

I have a 1988 Club Car DS gas with the original Kawasaki 341cc engine. Everything is stock (no lift kit or engine mods). We were out driving in the neighborhood at full speed when the cart bucked, almost like it ran over something small (it didn't) and lost power. The engine was still running fine.

We were able to get going immediately. It happened again shortly down the road before I turned around and drove home. In case it's important, we were at full throttle and also going down a fairly steep hill when it happened.

I believe it's an issue with one of the clutches or maybe the transmission, but not sure which or how to diagnose. The drive belt is new. Starter/generator belt is also new and is sufficiently tight. One other maybe useful bit of info: the cart is touchy when starting out. It wants to buck at initial throttle then settles down and rides smoothly. This suggests a clutch issue to me.

Appreciate any experience or expertise.

[meimk]

Need to clarify: You call it a power loss, but say the engine is still running fine. Did the engine lose RPM's- like down near an idle speed? Or did it race up like reving an engine in neutral? Or was the engine seeming to run steady but the cart lost ground speed?

[Toddyus]

Originally Posted by meimk

Need to clarify: You call it a power loss, but say the engine is still running fine. Did the engine lose RPM's- like down near an idle speed? Or did it race up like reving an engine in neutral? Or was the engine seeming to run steady but the cart lost ground speed?

Good question, sorry for the confusion. The engine didn't lose power, the cart lost ground speed. There was almost a thump and then the cart lost all propulsion. Stopped the cart, looked under and around it, then drove off like nothing happened.

[CP241]

I’m not super familiar with the KF82, do they have a rev limiter like the FE motors do? Sounds like you hit the rev limiter.

[meimk]

Try to look at the backside of the secondary clutch. If the towers get worn or broken it can “skip”. The spring can come unwrapped and is usually pretty obvious once you look for it. Could also be as simple as the shift cable getting out of adjustment and things vibrating out of gear.

[Toddyus]

Originally Posted by CP241

I’m not super familiar with the KF82, do they have a rev limiter like the FE motors do? Sounds like you hit the rev limiter.

I had not considered this, but according to the internet, the KF82 does appear to have a rev limiter. Not sure how this transaxle works, but would running full throttle with the additional speed coming down that hill cause the engine to rev higher because of the reduced load?

[CP241]

Originally Posted by Toddyus

I had not considered this, but according to the internet, the KF82 does appear to have a rev limiter. Not sure how this transaxle works, but would running full throttle with the additional speed coming down that hill cause the engine to rev higher because of the reduced load?

Yes it can. Rev limiter counts spark events. When the frequency of spark exceeds the set specification (let’s say, 3000 RPM as an arbitrary number) it cuts spark and shuts off the engine immediately for a few seconds-ish. It feels like you hit a brick wall and something just let loose and died. Then once you slow down a bit it picks back up like nothing ever happened.

I had considered secondary clutch spring or ramp problem but if you stopped and drove again with no problems, that’s unlikely. If it happened as you were driving full speed, going down a hill the clutches aren’t really doing much “work” at that point, so it’s also unlikely it would be a clutch issue unless there were a catastrophic clutch failure, in which case it wouldn’t drive again.

Im gonna have to stick with rev limiter. Final answer, lock it in

[Toddyus]

Originally Posted by meimk

Try to look at the backside of the secondary clutch. If the towers get worn or broken it can “skip”. The spring can come unwrapped and is usually pretty obvious once you look for it. Could also be as simple as the shift cable getting out of adjustment and things vibrating out of gear.

Thanks for the suggestions. By "towers" are you referring to the three "teeth" on the clutch cam? Not sure what to look for here.

Here's a pic from the access panel:
https://ibb.co/8NmCVgq

I did check the shift cable and it appears to be adjusted to spec. However, I can't recall now if I shifted out of forward or not when this happened. It could have popped out of gear and I didn't notice when I stopped because I could have instinctively shifted into neutral and back.

[Toddyus]

Originally Posted by CP241

Yes it can. Rev limiter counts spark events.
Im gonna have to stick with rev limiter. Final answer, lock it in

I'm leaning more and more toward this direction. What you described - brick wall - is exactly what it felt like. I ordered a tachometer and will measure revs going down that hill to confirm. Thanks for the input.

[meimk]

Originally Posted by Toddyus

Thanks for the suggestions. By "towers" are you referring to the three "teeth" on the clutch cam? Not sure what to look for here.

Here's a pic from the access panel:
https://ibb.co/8NmCVgq

I did check the shift cable and it appears to be adjusted to spec. However, I can't recall now if I shifted out of forward or not when this happened. It could have popped out of gear and I didn't notice when I stopped because I could have instinctively shifted into neutral and back.

In your picture: was that running at the time that was taken? I've never seen a secondary clutch hold full open like that at rest.