G9 Drive Clutch - 2 pieces?

[Parrotman409]

Hello! New to golf carts. Recently got a Yamaha G9 gas that runs but has a squealing type noise. It isn't the belt (removed it and started without the belt). It sounds like it is coming from the drive clutch. I removed the clutch cover then I took an impact gun and took the bolt off the centre of the drive clutch, and it came off very easily without a puller (seemed strange...?). I've worked on a lot of snowmobiles and I have never had a clutch come off without a puller. The back of the drive clutch (sheave maybe?) did not come off with it. It also comes off easily but as a separate piece.

Are they supposed to be 2 pieces? Pics attached...

[G1-G9]

Normally the squealing noise is the starter generator belt being a little loose.

[Parrotman409]

I checked the starter/generator belt and it seemed to have good tension and be in good condition. Sound hard to describe -- almost more of a chirp than a squeal? And definitely coming from the clutch area. That'w what led me to pull the clutch and question that it was 2 pieces...?

[slonomo]

Could the clutch be spinning on the crankshaft? That would cause a metalic chirp sound. Check the shaft for wear marks. The crankshaft should be a tapered style so when the clutch is installed and torqued down it should have zero slip. Sometimes I lap the two peices with valve lapping compound. If there are any marks on the crank it could be the issue.

Not sure on the 2 piece thing, never had that type of clutch. All the primary clutches I've ever worked on come off in one piece and require a puller bolt to separate. I work on golf carts, atv's and utv's, all the one's I've ever worked on are pressed on like that unless they have a straight shaft with a keyway.

[Parrotman409]

Well I'm certain it's an issue with clutch wear causing chattering. So I've ordered a new clutch. I'll post back here once it arrives and I install it.

[Parrotman409]

OK, so the clutch was part of my problem. Second part of the problem is that the connecting road bearing is totally shot. Can I get away with sanding/polishing that part of the crankshaft (it's scored a bit) or do I need to remove and replace the crankshaft?

[slonomo]

Originally Posted by Parrotman409

OK, so the clutch was part of my problem. Second part of the problem is that the connecting road bearing is totally shot. Can I get away with sanding/polishing that part of the crankshaft (it's scored a bit) or do I need to remove and replace the crankshaft?

If the crank is scored it's toast. If you can find oversized bearings you can have the crank machined down. With these small engines I usually replace the crank assembly with new parts, including the con rod and piston.

Polishing the crank will only remove aluminum bearing remnants from it, it won't do anything to the crank itself. So look closely, is the scoring bearing material? Or is it actual scoring on the crank? If it's bearing material, it might be able to be saved.

In my experience, if a crank has any wear on it at all, reusing it will only work for a short time. Tolerances are tight on the bearing surface and wear marks/scoring will eventually cause failure of the bearings.

[Parrotman409]

I used muriatic acid on the crank, and it was totally fine. New piston rod bearing, new oil splasher, and all new gaskets. Everything is back together now and it runs well!