Modern Vespa

Ok, So I'll admit, I've never worked on scooters, but I've heard that a variator replacement isn't that hard. Anyway, long story short I ended up with one extra part... a 1/16" thick washer. For the life of me I can't figure out where it goes. I tried running the scooter without it, but no luck. The Variator is noisy (like the belt is slapping the case) and it also can't accelerate. It'll start to rev up and then it'll bog down. I decided to go back to stock. So I put everything back, except that washer (still don't know where it goes) and the variator still doesn't work. SOOO I'm assuming that its a very important part. No idea on where it goes. Any ideas? Oh its an LX150 with the Malossi Variator.

Sean

Moved to General Discussion.

The shim washer (it's about 1mm thick) is vital to the correct functioning of the variator. You can do damage to the engine by running without it. It is perhaps the most important washer in the entire Vespa. Seriously, I'm not joking.

The 1mm shim washer goes between the outer variator half (the part with fins on it) and the bushing that slips over the splined crankshaft. It provides the correct belt alignment and, more importantly, it prevents the inner pulley half from colliding with the outer pulley half.

DO NOT RUN the scooter until you replace that washer to its correct location.

Did you replace the variator nut?

I put it there once but it was too thick, maybe I put the wrong washer there? :-S The most important washer of the Vespa? Of course I'd pick that one to mess up... Is the shim washer supposed to be silverish or a darker color?

Further, if you didn't get the outer half of the variator torqued down properly, or if bychance you pinched the belt between the inner and outer variator halves, you will end up with the outer half wobbling around, which will chew up the variator and possibly the end of the crankshaft. If you chew up the end of the crankshaft, you essentially have to replace the whole engine.

This is serious stuff. Variator re-assembly is not something to take lightly. We've seen enough horror stories here, and don't wish more.

while that makes sense to me, I'm wondering if you have a pic that can help better illustrate it. I have a feeling, as more and more people start trying to do this particular job, that it'll become useful.

I might be tearing some stuff apart tomorrow actually to replace my variator nut (single use! gonna put some loctite on it heh), so I might take pictures as well. But I forget if you have some already.

The shim washer should be just about exactly the same diameter (inside) as the crankshaft. Not sure what color yours would be, it depends on how dirty it is. Probably silver, but not guaranteed. The important part is that it's going to be fairly thin., even by washer standards.

Oh and whats the diameter of the shim washer? So I get the right one, theres three that are part of the variator, just wanna makes sure I get the right one there.

What is the torque on the variator bolt? 42 pounds?

I don't have the LX figure handy. For the GTS, it's about 60 foot-pounds.

Sorry posted that before I saw that... So the shim washer will be the super thin one, and then the other washers go on the various parts. And is there supposed to be a washer between the kick start gear and the outer half of the pulley? After messing with this so many times, I really don't remember.

It's the thinnest of the three. I don't have exact diameters handy.

No I didn't I didn't know it needed to be replaced... Even with 1500 miles on the variator huh? I'll go to the shop and see if they have them so I don't have to order it.

You want to replace the variator nut every time. I bought 4 of them today at Vespa Oceanside just so I have some if anyone I know needs one.

Ok, would it be one of those things I'll need a ride to go get assuming I get the variator functioning correct or is a short ride to the scooter place safe for the engine/me?

It sounds to me like you are better off NOT trying to drive it, even a short distance...

Better safe than...out a lot of money.

Good Luck!

Pictures would be helpful in having the awesome experts on this forum answer your question - if you can get them posted.

Desi B.

so I took a picture of what washers I've got. Hopefully you could identify where they need to go, just so I can be absolutely sure.

The one on the right is the thinnest, but its too wide to fit in the outer half, so I'm assuming its the middle one. The one on the left is for the clutch I believe. What do you think?

The one on the left does look like the clutch one, yes.

I can't tell from the picture much about thinness, but the right washer has to fit in that recessed area in the outer pulley half. If one of them fits and the other doesn't, you've got your washer.

So I have reason to believe that the noise and problems are in the driven pulley, not the driving pulley. I'm for the most part out of ideas. My instructor is coming by tomorrow to take a look, he used to soup up scooters for racing all the time back in the 80s. But in the meantime, anything you can think of for us to look at tomorrow?

It's imperative that you open up the driven (clutch) pulley (it's held closed by a strong spring) and get the belt wedged all the way into it before placing the clutch + belt combo onto the shaft. This allows the belt to stay out of the way of the variator outer half when you torque it back on to the crank shaft. If you don't do this step, the outer half won't be fully seated when you torque it down, and as soon as the belt moves the outer half will be loose. Engine damage will result.

It's also critical that the backing plate behind the inner pulley half is as far back as it can go.

Clutches don't fail very often, so I'm hesitant to think that the clutch is the problem.

As for the variator nut, it's supposed to be one-time use, but if you don't have a fresh one on hand, just make sure to use some Lock-Tite Blue on it when re-assembling.

Well it just seemed like it was coming from there when I was looking back on it, but I can't tell for sure. I'll wedge the belt in farther on the clutch side. I had it in there a little bit but I think I can probably get it tighter in there. My instructor should be able to pinpoint the problem, I'll keep it off until he gets here. I'll let you all know what happens.

Cool, we'll be interested to hear what it ended up being.

So, there is a shim between part 7 and 9?


Regards
Harvey

Harvey - where did you find that? I'd love the same foe the GT. The gts has more washers I believe.

the 2003 parts is in the technical forum

https://modernvespa.com/files/parts/GT-200-Parts-2003.pdf.zip

They're actually cut and cropped from the Parts manual (2006 UK version pg 37) in the Technical Forum.
[topic630]
Here's the GT200L version.


Regards
Harvey

it's a little interesting that it doesn't look like the parts in my variator. heh.

that's always a little disturbing.

for instance, I don't believe there was ever a washer in between the starter gear (which cups the outer pulley) and the variator nut. The variator nut has its own built in spring washer.

The part #6 I have as a relatively thin washer that fits between the bushing labeled as 2 and the outer pulley half.

The first GT200L set is from the 2006 UK manuals. This is the set from the 2003 (Italian) Manual pg35. Does it resemble yours?

Regards
Harvey

uhhhh kinda.

heh.

This is what mine looks like:
[img]http://farm4.static.flickr.com/3005/2680993656_8418f6ca52.jpg?v=0[/img]

So you can see how even the starter gear looks wrong.

I mean, it's definitely closer. Just kinda weird.

Wow thanks for the variator diagrams. I guess I just didn't wedge the belt in tight enough on the driven pulley because that looks exactly how I put it together... I'll get some help getting that belt deeper in that pulley so it has even more slack to play with.

So I got it fixed, and I'm almost embarrassed to say. It turns out that I had it right with the Variator, and there was nothing wrong with the driving pulley. My suspisions about the Driven pulley however were correct. The pulley was not able to expand. I didn't have a reference because I didn't test it before I took it apart to put the new spring in. It turns out when I took it apart and layed it all out in the order I took it out, I put the plastic spring guide on the wrong end of the spring, and that was preventing the pulley from expanding. We had this old scooter that had been converted to a stationary tow rig for hang gliding that we were using for reference.

So Lesson Learned:
Pay attention to which end of the spring goes where.

Thanks sooo much for your help guys. She sure is a lot smoother on the acceleration.

Glad to hear you got it working.

congrats on beating the vari problem and off on a ride. whoo hoo

So it was on the clutch side???

did you ever find out where the xtra washer goes?

Yes the problem was on the clutch side, the driven pulley. I guess I'm the only one who's screwed that up hehe. I did find where that extra washer went, as it was suggested early on, it was the shim between the pulley halves.

from your photo...

the top washer goes on the outside of the pulley half, the middle washer goes in the relief of the 1/2 pulley between the 1/2 pulley and the gudgeon pin. the bottom washer goes on the clutch shaft, protecting the bearing.

your 1/2 pulley also looks worn and your hands look like they need lotion.

best,
-greasy

hahahaha, mr. greasy says "put the lotion in the basket...."

haha yeah I kinda messed my hands up in a hang gliding landing... I hadn't flown in like 6 months and really botched the landing. For some reason I let go of the control bar when I landed :-S