Strange noise

[Abes]

Hi all, First post here. I've got a 2008 G23A Yamaha umax that I bought about a month ago. It has the 357cc engine in it. The previous owner said he picked it up from the golf course he works at and that they had replaced the motor/ tranny with a new yamaha unit about 2-years ago. Supposedly they preferred replacing the motor than trying to fix the original. It ran great but very slow so I removed the governor by drilling out the keyway on the bracket. Its runs ok but these rears are geared for torque (15:1) so its up there on the revs. I really need to jet it properly and possibly swap out the gears.

Anyhow, I noticed that it makes a loud noise after driving for a while which I've not been to pinpoint. Its hard to tell if its coming from the trans/ drivetrain area or the engine. The noise is intermittent/ not consistent but my best description is that it sounds like a blender is being turned on as were driving. It goes away after a bit but comes back later on. I've got a few picks of the clutch/ driveline and was able to get a video of it while it happened. Maybe someone can point me in the right direction because I'm at a loss..

[Abes]

Here are a few pics..

[Abes]

Here's the video with the noise. You can hear it start at around 11 secs in and dies out at around 1:35 mark when I almost come to a full stop. I tried capturing it again-for about 20 min but it didn't make the noise...

You Tube

You Tube

[griffo002]

My G1 made that type of sound cpl of times...Mine did it at low speed tho...It had me beat as where it came from...The only thing that I think it may have been was in the governor... I replaced the lock bolt nut with a longer one and screed in further..It never made that sound again after I did that...
I did a lot of repairs to the motor as well but nothing that I could relate to it making that sound if you know what I mean.
Griff.

[Abes]

It actually started right after I did the governor mod. Can the shaft of the goverener (inside the gear box) move up and down? It doesnt have any sort of lock nut or pin that holds the top bracket which has the cables connected to it holding it down. I haven’t had a chance to tap it and put a nut on it.. I’ve tried pulling the shaftt up and down but it seems to have something locking it in place so I wasn’t too concerned with it

[Abes]

Can it possibly be the input shaft bearing? I’ve got a vid of it running in neutral and it shows a bit of in and out movement behind the secondary. Not sure on what the tolerances should be.

[grantspec]

My cart has been making similar sounds. Also have modified the governor. If you figure it out please post your findings.


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[griffo002]

I am not sure how it all works as I have not opened up the rear end at all...maybe do what I did as mine goes fast enough that its dangerous...lol.

Ill post some pics later.