Modern Vespa

This should in no way be construed as a problem with the J Costa variator, with the possible exception that J Costa does not provide any concrete guidance on this particular issue.

I had done some measurements recently on the stock variator vs. the J Costa variator to determine whether the stock 1mm washer that fits between the stock gudgeon pin and the outer variator half was necessary when installing the J Costa. There had been some speculation, and I concluded that with or without the washer, the outer variator half would be 0.5mm out of alignment.

I now know definitively that you do need the 1mm washer when you install the J Costa, regardless of alignment. In case that wasn't clear, you DO need the 1mm washer when you install the J Costa variator.

The 1mm washer servers two purposes: as a spacer to keep the two halves of the variator at the proper distance from each other, and (more importantly) to act as a positive stop for the inner variator half, which slides on the gudgeon pin. Without the 1mm washer, the bushing in the inner variator half can slide too far on the gudgeon pin. This results in the innermost surfaces of the two variator halves being able to touch each other. Because they're both made of aluminum, they will grind away at each other, and move even closer together.

When enough of the two pulley halves grind away, the two halves of the variator move close enough to push the belt well outside the diameter of the pulley, at which point the belt will start eating into the engine case and the top of the oil pan. Yes, the rubber belt will eat away your engine case, and it won't even take very long.

In my case, the belt dislodged enough of the oil pan gasket to allow oil to start splashing up into the transmission housing, causing the belt to slip. Once I realized this was happening, I headed back to the workshop and stopped riding. Only today, four days later, did I open up the transmission case to see where the oil was coming from.

It wasn't pretty. It could have been worse, but this was plenty bad enough.

So here's my warning: If you've installed a J Costa variator and you didn't use the stock 1mm washer, DO NOT ride your bike! Re-install that washer immediately, or you will damage your variator and your engine.

The picture shows the damage to the engine case (circled) and the damage to the innermost surface of the inside variator half.

This message brought to you by Modern Labs... We fuck up so you don't have to.

Ouch! So how many dollars-per-hour value did you get from it, Jess?

I put maybe 1000 miles on this variator before I made the change of removing the washer. After that, it was only a matter of maybe five or ten miles before this started happening.

Sweet lesson. When in doubt, follow instructions and don't question their authority.

Well at least you got that good 1000 in. Ooh that doesn't really make it better does it?!

that sucks

anyone want to buy my J Costa

Sadly, my directions said nothing about the washer.

There's nothing inherently wrong with the J Costa, as long as the stock washer is retained. The same thing would happen if you removed the stock washer from a stock variator.

My J Costa Squeeks at Idle, This may be my problem.

Hey Jess, in your picture, the variator half shown is the JCosta right?

On the stock variator there is a washer that fits between end of the crank and the internal half of the variator. The exploded view of this in the GTS workshop manual incorrectly shows that washer with all the others directly behind the nut. It made for a confusing re-assembly. Is this the washer you're referring to?

Yes, although from that side it's nearly impossible to distinguish from a stock variator half. Yes. Well, it's a 1mm (very thin) washer that sits at the end of the gudgeon pin. I haven't looked at the exploded view, but there are in fact two washers that sit directly under the variator nut, in addition to the thin 1mm washer that sits between the gudgeon pin and the outer variator half. So, there are three washers total on the crank / variator assembly.

It is the gudgeon pin? I'm sure you're right. I'm just going on my bad memory. Greasy helped get mine back together in the right order. Someone did take pictures of my dis-assembly and they definetly helped on the re-install.

Thanks for posting this.

One difference between stock and j costa is that the j costa inner pulley half is free to spin on the gudgeon pin while the stock one has locators that prevent this.

If you left the washer off the stock (NOT that you should) I wouldn't expect to see as much damage.

That's an excellent observation, Patrick. If the J Costa weren't free-spinning, the innermost surfaces wouldn't grind against each other, at least not to the degree that they did. They would merely press against each other at full RPM extension.

So how much did this screw-up cost you? What's the replacement cost of the parts?

Not sure yet. I don't remember what a replacement variator costs. The oil pan gasket is probably trivial.

The J Costa itself (which is only half of the variator) lists at $270. As mine is now ruined, I'll be needing another one.

wait, this wasn't on 'the bitch' was it?????

zomg that'd suck.

Bummer, Jess. Sorry.
I just swapped out to the polini.
I still have my 'costa.
I didnt have any problems with it other than the top end feeling too "revvy."
(to use the tech term...)

I have ordered the JCosta for my X9. However i am not doing the work. Is Rockridge up for this? I am a little nervous now. Offline opinion if need be.

Ow Jess! Man, I hope things turn around for you after all this. And add me to the list of the appreciative for telling us what happens sans itty bitty washer yikes.

Harv

No. This was on the silver ghost, with Uno's engine. Same bike I had on Three Peaks Challenge.

I haven't seen the variator on a Master engine, so I can't say with certainty what its requirements are. I'm sure they're up to it, though.

I'm taking it in stride. It was a learning experience, and the silver lining is that we have the means here to get the message out so that nobody else has to make the same mistake.

The J Costa for the Master engine uses all the original parts (sleeve and washer), so no danger there (and it makes for a FAR smoother take-up as well as the performance boost).

Despite my original huge scepticism I am won over to the J Costa fan club.

Jess, sorry to hear about this - but thanks for being the guinea-pig!

'tis my burden, and my pleasure.

Just making sure everyone sees this...

It's a very good heads-up. I hope it gets passed on to any and all other Piaggio forums.

Thinking a bit more - do you actually have to replace anything? It seems to me you've just made up that 0.5mm anomaly (and then a bit) - you could always add an extra washer.

There is damage to the innermost points on each pulley half. I think that would subsequently result in damage to the belt, given the rough surface.

Jess, did your J.Costa come with a new bushing? If so, did you install it or reinstall the stock bushing without the shim?

The belt never gets that close - think what it would do if it met the washer! And it'd only be the lower toothed part of the belt, AND that is chamfered away from the damaged parts which could well be polished up.

Me, I'd run with an extra shim of some sort in there and see what happened.

Joel, can you go into more detail about the 2 variators. I agree at about 65 when I open the throttle the bikes now almost jumps from the torque with the Polini. Coming on and off the gas is not as smooth but in a good way. Which variator would you say is better for off the line, mid and then top end? I would love to hear more. Thanks.

I'm calling it a gudgeon pin here, but yes, I believe we're talking about the same thing. Metal sleeve that fits over the end of the crank shaft, and the J Costa spins freely around that. There's no way to use the stock gudgeon pin with the J Costa -- the two respective gudgeon pins have a different outside diameter. So yes, I used the J Costa gudgeon pin.

Initially, I used the 1mm stock shim. After about a thousand miles, I opened it up to measure all the parts and determined that, including the J Costa backing plate, I could place the outer variator half either 0.5mm too far in or 0.5mm too far out, but not in the exact same spot as stock. I chose to remove the washer and err on the side of having the pulleys too close, which (I realize now) was a huge mistake.

I know that some people here (you included, I thought) had measured the parts and decided not to use the stock 1mm shim. I'm urging all of those people to seriously reconsider. The shim is very much necessary.

I'm wondering why the bush ('gudgeon pin', but it isn't one, it's just a 'sleeve' or 'bush') is a different diameter for the J Costa for the 250 and maybe other engines - far better for them to leave all that alone (as they have done for the Master engines). It'd save all confusion and some disappointment

Yeah, sorry. That's just what greasy taught me to call it, and it stuck.

I'd be happy to call it a "curmudgeon pin" in your honor, Jim.

One more bump for good measure before this thread disappears below the surface.

i did not use the shim (made sense not to)
so today i pulled mine apart to take a look

my variator halfs did not touch each other but the belt is rubbing away at the case just like Jess's

Bummer! Still got the shim to put back in?

Hmm, I got that one wrong, sorry. It's the 0.5mm length difference that's up the bucket...