Modern Vespa

2007 GTS 250 ~23k miles.

When starting from a stop, in about 15-20 ft a grinding/dgrating/crunching type noise is heard. It goes away quickly and never occurs while riding only when starting from a standstill.

Variator replaced recently along with belt, rollers and sliders.

I'm thinking clutch? Thoughts?

Clutch chatter? Pull the cover and give it a blast of air. You might want to wear a mask.

Checkout everything else while you're in there.

I had similar symptoms and cleaning solved the issue. YMMV.

Good luck.

FAQ: Shudder, graunching noise on take-off? Sealion?

check that bearing on the exhaust bracket, put it on center stand and check twist play

Thanks for the feedback and I should have mentioned it is still there after de-glazing the clutch bell and pads.

The exhaust bearing was checked and is fine as well as side to side play.

If bearing issue, I would think it would be constant.

It is a grinding, screeching type noise that seems like a piece of metal gets hung up. Maybe spring issue.

Regardless, my plan is to take a clutch assembly off another GTS 250 that has no issue and put it on for a test. If that solves the issue, then it is a clutch problem.

Have you ever greased the clutch bearings and checked the seals?

yes

oil in the gear case?

I would that would be a constant grinding noise instead of a quick 1 or 2 sec noise that only happens about 10-20 feet from a dead stop, then goes away and never return except again from a dead stop.

Just a hunch, but re-check your variator fixed face.

If it didn't sit tightly on the boss and had any play, it could tear up the splines on the cage it it could slip.

I usually try to pull the driven face open to create enough slack for the belt to ensure it doesn't interfere with tightening down the variator. It doesn't hurt to dry-build the variator without a belt installed to ensure everything seats properly.

True but then it would be a constant grinding noise.

Not really, the force of the rollers on the belt will force it to turn along with the variator. It might be slack enough near idle to slip.

the coincidence of having just serviced the variator is probably a key ...

apart from the above mentions I'd also be checking the correct placement of washers with the var and also correct on the clutch shaft where it goes throught the cvt case. and check that bearing on the case as well.

ps thank if you cleaned the clutch on this service then need to regrease it.

Yep, brain farted on that one.

did you figure it out yet?

This sounds like a glazed clutch to me, which doesn't appear to have any kind of 100% permanent fix other than replacing the clutch assembly and housing.

not yet but was going to pull a good clutch out of one of my fleet of 250's throw it in as a test but she went and bought another 250 and is going to sell this one. Has had a lot of maintenance, some issues with the fan and speedo all replaced.

She is going to sell it cheap so maybe a good cannonball scooter?