Modern Vespa

I can see it's rubbed on the new belt on the outer edge. Basically, I think on the inside of the transmission cover. Beyond that, though, I don't know where to look or how to tell where it's rubbing. Any advice?

Oh, and I forgot to point it out in my latest set of pics, there was a significant amount of rubber dust inside the trans. You can kind of see it at the bottom in the 3rd pic above, the one showing the angle coming off the front pulley.

Look for shiny metal, that will be where it's rubbing

Thanks, Wayne. I'll take a look when I go home for lunch and see if something jumps out at me...

Quote--"took a quick look in from the back inspection port".

Where is this inspection port on the 500?

So, looking at the casing at lunch time, there's a few places I see what might be rubbing. I've snapped a few more pics, though I'm not sure how well what I see translates to what my phone sees...

And a couple more. Sorry the one on the bike is hard to see. I was shining a Halogen work light at it, but it's still not great

I also took one of the inside of the trans case over the lower middle bolt, but it didn't turn out. I was using a flashlight, and that one spot is just completely washed out so you can't see anything.

Take a look at the first pic in the newest batch. It's the great big open space in the outer transmission cover, on the left on that pic.

It's really more of a heat vent, I think. And it doesn't give you a view of much other than the belt in the clutch, but it was enough to let me see that there was a problem.

here is my take. looks like normal rub on belt. almost every one I have serviced has had some lite rubbing on the belt. happens a bit more on those who ride in the upper speeds.

Now on to the Fuzzy washer. You have put many many miles on with a Fuzzy washer with no issues. You only had an issue when you installed a new belt improperly and didn't allow enough slack before torquing the vari, thus causing it to be pinched. Same with the 2nd used belt, Which might have been installed backwards as well and unknown mileage on it too.

Many many folks have thousands and thousands of miles on with a Fuzzy washer with no issues.

If one of my customers wants their old belt for an emergency spare I mark it with a paint stick on the direction and also mileage so they know. Typical I don't recommend carrying a used belt as a spare, why not just carry a new one and use that one as your next one for a normal change and then get another new for a spare again. this keeps them cycled thru so you don't have an old one.

CubsKing99:
Use a Black Marks-A-Lot large chisel tip permanent marker inside the case to locate any rubbing at that moment.

How?

Mark any area with possible rubbing and than some. Replace case and drive around for a bit. Open back up and the black marked area will be buffed off.

Makes sense. It'll have to wait until next time, though. I put my Fuzzy washer back in tonight and buttoned it all back up again. I'm planning to ride it to a practice race tomorrow after work, so we'll see how it feels...

Mark

My understanding of the washer is that it sits between the variator halves in addition to the standard washer that is already there. If so it has no effect until the halves close up when, by keeping them slightly further apart, it makes the effective pulley diameter smaller and therefore the engine revs higher. If your weights are quite heavy ( and I suspect that yours are ) then it compensates for the fact that your variator locks out at relatively low rpm.

This would also reduce the tendency for the belt to scuff because it will sit a little lower in the front pulley.

I don't want to be a prophet of doom but must ask if you have checked for up and down play in the crankshaft. Obviously there should be none and also very little end float.

Does the variator behave normally as you accelerate? i.e. If you used full throttle does the engine hold between 6 and 7 thousand rpm until you reach ( say ) 70 mph?

So, as I posted in the 2014 fall gathering thread, I had another near belt failure this past weekend while I was out on the road. I'd put just under 2000 miles on that brand new belt. While talking to OAD, I discovered that I had put a couple of washers on incorrectly. When I put the new belt on, I fixed that. About 200 miles later, I got home.

On Monday, I tore the transmission apart again to look it over and clean it up, since I wasn't able to in the AutoZone parking lot where I'd changed belts on Saturday. What I found was utter carnage. I'll let the pics speak for themselves and post some analysis in another post. I've included the replacements I grabbed off of my parts bike for reference.

For larger size images, click on the pic to follow the link.

Debris inside the transmission:


Destroyed sliders & horseshoes (ignore the leaf - that was just on the ground in my garage...):




Outer transmission case:


Where it rubbed the outer transmission case:


Ramp plates:


Top-down shot of Variator back faces:


Side profile of Variator back faces:




Variator backs:


Original




Replacement

So, I'm not exactly sure all of what happened, but I can make some educated guesses. What I know for sure is that, as several people suggested, the bushing had worn badly. As you may be able to see in the pics above, it not only wore away some of the metal around the brass bushing, it also seems to have melted and reflowed it. The brass is a lot thinner on the old one and also protruding from the back. And on the spare one, there's a little seam between two segments, while on my old one there's not.

That made the back pulley half wobble a bit on the drive shaft. In turn, that must have let the belt come out rub on the transmission case.

After I changed belts, it must have just kept getting worse. It must have finally gotten loose enough that the sliders slipped sideways, or the horseshoes broke and started jamming on the back. You can see the gouges left in a couple of the above pics.

I put the replacement parts in on Tuesday and did a little riding in town on Wednesday. The bike is SOOO much smoother now when I'm getting on the gas, which indicates to me it's been going bad for a while now...

Hopefully this weekend I'll be able to get out and do a real road test to make sure it's all good at highway speeds, too...

yup the brass buching is totally shot and the vari halfs are gone as well from wear.
Glad you had spares to get it back to normal again.

That is a mess. Sorry to see you having these problems.

I do hope you have changed the slider/roller ramp plate. While you are at it check the crankshaft for radial runout. I believe the specs are in the service manual.

Yep, I replaced the whole drive assembly: ramp plate, sliders, horseshoes, shaft-covering collar and inner and outer face pieces.