Modern Vespa

I recently installed 5g Dr. Pulley sliders in my ET2, replacing the heavier 7.2 Malossi roller weights that came with the Multivar. While I had the airbox out I also popped in a new Malossi red filter. I also put in a fresh plug to do a chop.

Everything I have read about going lighter on variator weights indicated I would gain acceleration, but I'm currently experiencing the opposite. My ET2 seems to pull noticeably slower off the line now. Top speed is also slightly lower. Also, I seem to occasionally lose throttle response going down hills when I attempt to accelerate toward the end of the hill (it eventually kicks back in).

I'm trying to figure out what is going on. Initial plug chop looked good so I don't think it's related to the new air filter leaning me out. My guesses at this point:

1) There's a break-in period for the sliders. I haven't found any info on this so it's merely a guess. I'm gonna keep riding it for the next few days to see if there's any change until the weekend where I'll have time to get the variator out again.

2) I installed the sliders incorrectly. (I followed the directions posted by Dr. Pulley here: I'm going to plan on taking a look at them when I get a chance to make sure they're still in the position they're supposed to be.

3) The Malossi Multivar is designed to work with rollers and doesn't play nice with the sliders. I haven't seen that this is the case, though it does appear all of the components of the Multivar were designed to work with each other. If the sliders appear to have been installed correctly, I'm gonna go back to the rollers and see what's up.

Does it sound like I'm going about this the right way? Any alternative things to look for? Any thoughts or advice about tackling this problem is greatly appreciated! Thanks!

Hello,

First up, unless you've got a race spec tune set up on your ET remove the Malossi filter, it's letting in far too much air.
Trust me on that, stock is plenty enough for my tuned 70cc!

Next up roller weights.

Lighter doesn't mean faster off the line
Heavier doesn't mean greater top speed.

Your Scooter only has one ideal/perfect weight, be it what it was, clearly not what it is now, or something in between.

The roller weights are to make your Variator variate at your engines peak power band.

Watch this video, the guys English is a struggle for him but he is bang on the money with what he says.

The sliders are not compatible with the Malossi variator. I asked here if it would work, but nobody replied. So I tried it. Huge disappointment. Then I put the sliders in my stock variator and it made a huge difference. Not only was acceleration much better, but the rattling sound on hard acceleration was greatly reduced, too.

BTW, I installed 5 gram sliders in a 2006 LX 50 4 stroke with the Malossi 80cc kit.

Malossi seems to use smoke and mirrors top obtain what can be done simply.

Are the Dr. Pulleys EXCATLY the same size as the Malossi weights OR the same size a stock?

Once you have corrected any faults with your engine's carburation or ignition then correct pulley weights are a matter of obtaining the correct engine rpm during full throttle acceleration once over about 15 mph. Your engine should run at something between its maximum torque and maximum power rpm until the variator reaches its maximum possible pulley diameter. Maximum power rpm would give the theoretical best performance but probably too frenetic for general use and for good fuel economy.
You need a rev counter if you are experimenting with pulley weights. If you establish that the target rpm is being achieved then any engine tuning can be directed at getting more power at that engine speed. Dr. Pulley sliders have a geometry specially designed for the stock variator so if the Malossi has different ramp geometry the behaviour will be unpredictable.

Oh wow. This is the definitive answer I was looking for, thank you. Hopefully the next person who is thinking about trying this will see this thread and avoid the expense and time spent!

I was going from the Malossi rollers to the Dr. Pulley sliders, so I was changing the shape as well as the weight (see OP). My thinking was the lighter weight would improve acceleration and the slider shape would allow "higher gearing" which would counteract the lower top speed lighter weights would theoretically bring.

I will say replacing the stock variator with the Malossi Multivar yielded a huge improvement all-around. If it wasn't such a PITA to remove the clutch to get to the contra spring I could try the stock setup with the Dr. Pulley sliders to see if it achieved the same results as the Multivar did, but I think I'm just going to go back to the Malossi rollers. Maybe I'll try the 5.7g rollers that came with the LeoVince pipe to see what effect they have.

So now you tell me!

Might be some mis-info in previous posts, here's my take.

Malossi filter should be fine as long as it's a sponge replacement and not a pod. Sliders are interchangeable with rollers and should be compatible with Malossi vario as long as they are correct size. 7.2 to 5.0 is way too big of a change if no other mods.

Playing with variators can be like Alice going down the rabbit hole. Part of the smoke and mirrors and the up-sell. You get more bits so it must be better! If other system/mods can be made to work without contra spring why change it on a stock scooter? Why use "stock" Malossi on a modified scooter? Malossi already has lighter or different weights than stock but because of the smoke and mirrors their weight choice cannot be used as any kind of yardstick. So you cannot use the Dr. Pulley 10-15% theory. You could buy some 7 gm Dr. Pulleys which may lead to a better ratio spread. They are supplied to go with the pipe and use the stock variator pulley because the pipe will raise the HP and needs increased the rpm to do so. So the lighter weights will allow the engine to reach those needed increased RPM.

Northernbill is your man. I depends on how much you want to do and what your expectation are. For 50cc tuning he can point you towards 50 cc tuning on a UK forum. Where hundreds of spotty face kids want to go faster.

I wanted to try these sliders with my multivar is the consensus still that they don't work?

Are you using the stock counter spring or did your Multivar come with a spring?

Multivar came with a spring I think it's yellow

OK the problem you have now is to ascertain what the correct weight might be for use with that spring.
Most information out there, anecdotal or otherwise, will be for a stock counter spring.
Multivar came with 7.2g weights.
A cheap tacho would be a good "investment" so you can tell what is happening.

I've installed a tachometer to my dash. I have 6.4g rollers now but I'd like to go lighter. Is there a correlation between roller and slider weights? How do I use the tachometer to figure it out?

And yes I believe the multivar came with 7.2. But I went with lighter weights

If you, or anyone, could explain how to use the tachometer to tune the variator that would be amazing

You need a tachometer with a reasonably fast response rate - many out there are quite dampened and not helpful for tuning.

Put a camera in a place that can monitor the tach and the speedo simultaneously, and take a video as you run full throttle from stop to max speed. Pull data points from the video and plot speed on the X axis and RPM on the Y axis. Maybe do this up a hill or two, too.

Change weights (or springs or rollers or variators or whatever you're varying), repeat. You'll have a different line for each configuration, and can decide what trade offs you like best in terms of acceleration and top speed.

Of course, manufacturers do this when designing the scoot in the first place. And they're also taking things like fuel economy and reliability into consideration.

To spend a lot of time tweaking the stock setup is to believe that the manufacturer didn't understand how you wanted the scoot to behave in all of these dimensions. I'm of the opinion that generally, they do understand, so I don't do this on my machines except maybe out of curiosity. If you want to go meaningfully faster, or get meaningfully better acceleration, you have to upsize the scooter. Fiddling around with all this stuff at the margin feels mostly like a waste of time.

Ah but many of us were made to "fiddle around". I agree this tendency has resulted is much wasted energy but think of the wonderful inventions that have resulted!**
**No inventions have resulted from my fiddling, but I had fun!

My setup is not stock btw. I have a 70cc kit with a yasuni R and 21mm carb. Among other things

And yes fiddling is 90% of the fun for me

Oh, don't get me wrong, I enjoy a fiddle myself too, but let's be honest that the incremental effect is minimal, the cost/benefit ratio is high, and a lot of people get themselves out over their skis.

You know how to really soup up a 50cc? Just buy a nice used 150!

I had to to get rid of my Dyna when my son was born and a friend gave me the 50cc vespa. I think about getting another real motorcycle everyday

on my hpe I've been recently testing 13g and 12g malossi instead of stock 14g. although the 12 and 13 makes it rev higher during acceleration it doesn't result in better 0-60kph times in fact they were worse with the 12g where as 13g was similar to stock.

why? cause although the increased revs have taken it nearer to peak power at 8250rpm it's taken it further from the peak torque at 5250rpm. the loss in torque hurts

so although tracking your revs while experimenting can be nice, unless you know what rpm you're targeting then it ain't gonna help much. accurate time vs speedo measurements are what you need (do not use phone gps - too inaccurate)


notes:
I'm using stock variator
peak kw/nm listed in the manual.

Exactly.