Yamaha G16 rattle noise and slow

[ottoguy]

Just picked up a Yamaha G16 1999. Got the motor running well and the cart runs down the road ok. There is some noise/rattle when running down the road though. When in neutral and reving the engine there is clearly a rattle noise like maybe the clutch? When I removed the belt and reved it up there isn't any noise. The previous owner said he removed a heavy duty spring the owner before him added and put in a red spring. I removed the cover on the drive clutch and it looks ok, however it doesn't look like the factory unit.

Also the cart only seems to get up to about 13-14mph. Could this be the clutch or something else? Is there any other testing or diagnosis I can do? If I remove the driven clutch is there some easy way to tell if they are bad?

I currently have a spare cart I was trying to fix so I could try swapping the clutch parts over, but I'm not sure if they are good so I don't know if I'm swapping bad parts to replace bad parts.

[pilotdane]

If the engine is getting up to max rpm's the lower top speed could be the primary or secondary clutch or a combination of both. The primary is actuated by centrifugal force (engine RPM's) while the secondary is actuated by torque.

Jack the back end and block it so both rear wheels are safely off the ground. Then with the seat and rear access cover off run the cart and watch the clutches. As you rev the engine up you should see the side of the primary clutch close and cause the belt to ride higher. If the clutch doesn't smoothly "shift" or if it doesn't close fully then there could be a primary clutch issue.

The secondary clutch is actuated by torque so it's harder to see in operation. A assistant to drive while the other watches the clutch is one way. The secondary moves/operates the opposite of the primary. When not driving the clutch plates are close together so the belt rides high. As torque increases when driving the clutch side plates move apart with plastic buttons riding on the smooth ramps. If is sticks, doesn't move freely that's a problem.

[slonomo]

The speed is normal for a goverened cart. Usually the manual wants you to set the governor between 12 mph and 15 mph. If you modify or bypass the governor you should get close to 20 mph with stock tires and stock engine.

Rattling is definitely a sign of something not right. If you know the secondary clutch has been modified, that's where I'd start. Sometimes you have to remove the clutch for a full inspection, but getting in there up close with a flashlight can sometimes reveal an issue.

All clutches wear out eventually. If the clutches are old, consider servicing or repairing them for best performance.

Plowman's Carts is a good place to get your clutches fixed or replaced. They are on the sponsors page.

[ottoguy]

Thanks for the replies. The rattle seems to mostly be when it's revved up in neutral. When going down the road it seems the noise is bit more of a whine. It may be completely normal, I've never owned a golf cart, just seems a bit loud.

I put it on on jack stands and ran it. The clutches seem to operate as they should. Without removing the rear clutch I inspected it and it appears to be fairly new. The rubber ramps are new looking and the are lined up as they should be from what I can tell.

Thanks for the info about the normal speed and the adjusted speed. I had read somewhere 18-20 but didn't know that wasn't without modifying the governor.

For now I'm going to just run it a bit and see if things get worse or stay the same.

[slonomo]

Yeah, don't try and fix something because of a random noise, you'll be chasing that thing forever. Golf carts are off road vehicles and when older can have some little annoying noises. As long as your cart runs good, drives good, stops good, and you're doing the correct maintenance....you should be ok. Get a factory service manual and do all the required maintenance.

[rstacy]

Your description would point to a worn secondary bushing or input shaft or both. This very common in a G16.
You can remove the secondary clutch and see of the input shaft has ridge worn in to it.
Or you can shoot the secondary with a healthy shot of grease and see if it quiets it down.