Modern Vespa

Are you not simply at the rev limit of the engine with the current belt set up & final drive ratio?

If this is the case, you can do one of four things to go faster:
1. Increase rpm limit of engine
2. Up-gear the final drive
3. Solve a possible drive belt range issue
4. Fit a larger diameter rear tyre

Heavier rollers should indeed help your top end with the kit installed, but going from 6.5g to 9g is a pretty big jump. Going too heavy will give you top end at the expense of off-the-line performance, as xantufrog indicated. It's a fine balancing act finding the right weight, but I'll wager the best compromise is a little lighter... perhaps 7.5 or 8g.

I ran out of time tonight so tomorrow i'll check if there are any identification numbers on the belt - am i right in thinking that there are two different belts - one for old ET2 and one for new ET2 variators? I'm not too sure how many miles the belt has covered so i'm ready to change it just in case - i'm thinking an original Piaggio one to suit the older sized variator. Do you know if the clutch bell/pulleys are different sizes too on the newer ET2s or perhaps the gearing is different

Hi Ninemeister - have you any more info on this idea - i'd be very grateful - Thanks

To be honest I don't know the answer to any of these questions, except that if you have the modern variator, why would you buy the belt for the older variator (if indeed there are different belts)?

Yes I think you are possibly very right.....7.5 to 8g feels right to me too....... I'm not sure about the belt as of yet..........my thoughts are that similar modded ET2s seem to reach 50+ so i'm guessing I've got a drive-belt/rollers puzzle to solve still because the engine is still pulling strongly and isnt fully WOT but its as if its just not being allowed to put the power to the wheels somehow - hope this makes sense.

What i'm thinking is that if the modern variator is slightly larger diameter and its been fitted for whatever reason still using the old belt which is perhaps smaller then it wont go up the variator pully to the top and so wont give full top end perhaps? dont know really just guessing i suppose.

Is there a way to tell how far the belt is reaching up the variator perhaps?

I've got no direct experience of it, but how hard can this be to work it out?

Looking at the photo below (of my daughter's LX drive belt) it is clear that to get the maximum speed from the assembly you want to get both halves of the driving pulley as close together as possible to achieve the largest pulley diameter & similarly the opposite at the driven end.

So after stating the obvious, logic also tells me that if the belt is too narrow it will not ride up to the top of the driving pulley so you will reduce the overall drive ratio, so there's one thing to look at.

Next up are the rollers - from what I can tell the weight of the rollers causes them to be thrown out under centripetal force which then pushes the inside half of the driven pulley together. Thus, if the rollers are too light or worn, even at max rpm you may not be generating sufficient force with the existing rollers to achieve the maximum drive diameter.

Is this enough for now to get you thinking??

You need to put engineer's blue on the pulley faces and then take a quick run up the road.

Yes that sounds like a very good idea - at least then i'll know if the belt is getting to the extremities of the driving pulley

I've found some info on ebay re different belt sizes by the look of it for older and newer ET2 variators

http://cgi.ebay.co.uk/Piaggio-Zip-sp-2-Stroke-ET2-Scooter-Pre-2000-Drive-Belt-/270552647905?pt=UK_Motorcycle_Parts&hash=item3efe31c8e1

http://cgi.ebay.co.uk/Piaggio-Zip-Vespa-ET2-LX-Post-2000-Scooter-Drive-Belt-/270552655675?pt=UK_Motorcycle_Parts&hash=item3efe31e73b

This seems to me that there are two different sized belts and i wonder if that is whats limiting my ET2 if the old belt has been fitted to the new variator in error.

I'll try the engineers blue first to see if it tells me anything interesting - thank you very much for that great idea

.


So here's tonight's update..............


Took the cover off and marked the variator with a permanent marker (checked on the internet and found that this is used sometimes as a cheap alternative to engineer's blue)

Took the scoot round the block a few times and got it up to its top speed.

Came back and looked at the marker pen to see what had rubbed off and what had remained..... see photos

Also made a note of the markings/numbers on the belt..... Piaggio 2/478954/3 20081..... i'm hoping that this is a part number and it can identify which belt i've got with these rollers/variator.

My ET2 is de-restricted and stock (apart form the exhaust but its not performance just the old one was rusty and it does 41 mph. I really think it could do 50, but the thing is with 50CCs they are so dependable on the smallest things, like weight of the rider, wind, road, the amount of ware on the drive belt all those kinds of things. But still with all the standard scooter mods (Performance exhaust, Rollers, Carb, that sort of thing, and if your really up for it, more fuel flowing, upgraded piston and drive belt) So I love that you're gonna see how fast you get one to go. I always wanted to try to but I didn't want to be spending money on stuff I didn't need at all, and I'm not much of a mechanic.

I also think its great that you got an ET2 and are enjoying it, I got mine when I was 16, and have absolutely fell in love with it and its opened up a whole new world of fun, not only on the scooter but a love for bikes in general. Keep us updated and keep trying

So.....

I've just ordered a new drive belt - going to give that a try when it lands.

I'm assuming that the old one is worn out, and with it being stamped up as piaggio (looks like the original belt) and the scoot having covered 12000 miles

Hope that I've ordered the right one - I've ordered the belt suitable for the 19mm rollers/variator, I think that one will be the right one.



.

I hadmy local Vespa mechanic change the rollers, however, the rollers I had was the wrong size(came with LV pipe) so he just changed half of them to heavier and cant remember which weight unfortunately, Im usually anal about keeping track of changes to my bikes. It did help with slightly higher top end.

Latest Update..........


I did a little research into the belts that are available for the ET2, there appears to be 2 different belts available, 1 that is for ET2 pre 2000, the other for post 2000 models.

However as you know, my ET2 is a 1997 model but seems to have the variator from a later (post 2000) model.

I ordered a belt for the later model (post 2000) as this i felt would be the correct size belt for my 19mm rollers/variator. I fitted it today and what i noticed was that the newer belt looked similar in length but that it measured 18.5mm in width, the older belt only measured 16mm, so i'm guessing that it had worn and stretched etc.

I also changed my Main Jet size to a 78 because the one that was in (jet was an 86) seemed to be be running a bit rich and at WOT would stutter, it seems fine now and a plug-chop shows a nice chocolate brown colour, so i'm much happier with that, i guess it'll help my fuel economy a tad too.

Took it out on a run and hit 50mph (indicated) without too much sweat - haven't had the chance as of yet to take it up to its very fastest - so will post again when I do.

In the meantime i'm going to mess with the needle clip position - the clip is in the very top position at current and i'm going to move it down a notch at at time to see if the performance get better or worse - anybody got any suggestion on this?

Also I want to disable the auto-lube to ensure that it doesn't become under-lubed - I've heard that 70cc kits run hot and if the lube isn't up to the job then they can seize - I've decided to mix in the tank - and if anyone can tell me the best way to disable the auto-lube i'd be very grateful

I'll update my signature with the new info, I'm tempted not to include the cost of the new belt because its just a wear and tear item.

You can adjust the oil metering rate of it. I'd do this, personally. Autolube is superior to premix in stock and milder tuning scenarios. A premix setting will be too oily at idle and underoiled at WOT. If you up the premix level, you might be safe at WOT but will be too oily for an even greater amount of the low-range. = fouled plugs. Plus, increasing your premix level will lean out the fuel/air mixture, which = hotter combustion temps. I'd just tweak the oil metering device rate up very slightly and call it a day - this won't affect the fuel/air ratio, and will still adjust the amount of oil for rpms and throttle position (which premix will not).

An important thing to understand: the fuel/air mixture is the primary contributor to seizure, not the oil level

Agree. I kept the autolube enabled on my kitted Yamaha Vino and never had a problem. Just make sure the A/F mixture doesn't go lean and you'll be fine.

The variator also wears out. Put a ruler, pencil or anything straight against it and see if it has become concave. Yours don,t look so bad but you can always check. Mine ran a lot better with a fresher(not necessarily new)second hand variator i got from a local moped shop. Also a tight, fresh (not stretched out) belt is crucial. Good luck.

Hi Guys,

I wonder if there is anyone out there who could advise me on a problem I'm having with my ET2 please?

Firstly I must admit that my knowledge of bike maintenace is next to zero, I know where the petrol and oil go and that's about it!

So, the problem is..... in the morning my bike is fine ( Garaged over night ) but in the evening ( after bike has been outside the station ) when I pull away either from a stop or slow down the bike just dies!, it then gathers pace and shoots off as normal.

If it wasn't for the fact that I have to negotiate 2 busy round abouts ( R A ) I would grin and bear with it, but last night I nearly " bought it " on the 1st of my R A's, then again at a set of traffic lights it died from a stop - level surface pull away.

I don't think it's the belt or rollers as they've been replaced without making any difference to the bike..only my wallet!

Also this doesn't happen in the summer or when it's dry only when it's damp or has been raining.

Over to you guys, appreciate any imput,

I wonder if its possibly a spark plug/ht lead problem - i know on cars when these get damp/cold that they cause problems - i'm no expert as you can probably tell from this post, but that is where i would start, i'd check to see if the lead to the spark plug was damaged or not and also i'd check that the spark was strong/make sure the spark plug was hand tight/check that the spark plug rubber cap which protects it from the elements was not split or damaged/possibly change the spark plug - perhaps some other MVer can chip in here to help you - hope you get it sorted!!

Hi,

So kind of you to reply, I didn't realise where to post a new question, so tagged mine on to yours, cheeky I know but you where getting sensible responses and I hoped someone woyld look kindly on me and help!

Good luck with your challenge mate, keep the faith

My pleasure - hope this helps you!!!

Crazy Caz! On one of my scooters used to behave like yours and I needed to adjust the carburettor depending on the weather, temperature and air pressure. I guess it has to do with the level of oxygen in relations to the amount of fuel. When it was cold and damp the scoot needed more fuel. On the Dellorto PHVA carbs that means you need to adjust the "air screw" inwards or clockwise. Don,t know if this is your problem but you can try. Good luck (Maybe you have a different carb, I only have experience from the PHVA,s)

Any thoughts on this anyone?

I've moved the clip down to the centre notch (middle notch of 5) and it seems to have made the mid range performance better, but I've noticed that the period in between tickover and mid range is more stuttery, the 'popcorn' sound that you get is now higher up the rev range and takes the engine a while to 'catch' at these revs - I hope i've described this well - any help/ideas would be great

Can you remember what Main Jet size you had running best with this???

.

Heres some more info..............

When I replaced the drive belt there was quite a bit of rubber dust inside the drive belt casing that looked like where the belt had rubbed away, if you remember the width of the old belt was 16mm versus the new belt that was 18.5mm. I cleaned the casing out completely.

I'm still not convinced that the problem that I'm experiencing with the top end speed is down to the engine power, when i went out first time after replacing the belt it hit 50mph (indicated) but only after a week it seems to be a little less (lets say 47).

So tonight I've removed the variator belt cover again and the black rubbery dust is there again, I measured the belt and its not as wide as when new (only 4 days ago!!)

I was cleaning it out when i noticed that on the driven pulley faces that the belt pulls against that there was some moderate pitting (before I bought the scoot it stood for quite a while unused and I wonder if the pitting is rust from that time it stood) and I'm guessing this is abrasive to the belt and is wearing it away quickly, hence it being narrower and not hitting 50mph again?

What are your thoughts??

.

.

............. And here are a few pics............

First one is of the variator now that the new belt (before it wore itself out) reaches the top, its worn the permanent marker pen lines off that were in the earlier photos so i'm happy that it did hit close to the max (when i first took the scoot out it flew up to 50mph without too much trying).

Second photo is of the rear pulley faces showing the rust marks that i think are damaging the belt, the belt is narrower already an I've only done about 50 miles on it, i'm guessing that the rust is acting as an abrasive on the belt's rubber compound.

Lastly, a photo of the black dust thats been shaved off the belt, the casing was cleaned out fully when i changed the belt on Monday (only 5 days ago)

.

.

Okay - latest update.........


Smoothed the rust areas on the driven pulley faces with reducing grades of emery/wet'n'dry, a nice polished finish now, and to the touch only a very slight difference to the rest of the undamaged pulley face.

Cleaned out the variator casing so that its completely rubber dust free.

Ordered another belt, but not going to fit it until I've run around for 50 miles or so and I've had time to check the casing for any fresh rubber dust.

.

Sounds like a good plan. I think the condition of the components looked bad for belt life before

. .


The rusty bits on the driven rear pulley were only where it looked like the belt had touched for all those years left idle, as if the belt had trapped in the moisture.

.

Yeah, I'm sure that's no good for the belt - sand it down real quick. Plus the radial friction might hold the belt at certain positions slightly longer than it should

Yes - done that - I'm going to run it around for an hour tonight and then take the cover off again to have a good look at it.

'

I think i'm getting somewhere now....

My new belt had arrived in the post today (2nd replacement) when I got back from work. So I took the opportunity to take the scoot for a 15 mile run, when I came back I opened up the variator cover and had a good look, no sign of any rubber drive belt dust since I'd removed all the rust patches and cleaned it out fully, so I replaced the worn belt with the new one.

I've taken a few photos of the old and new belts, first is of the very original belt compared to the new belt, second is the first replacement belt that wore away within about a week.

The results.... took the scoot straight out after fitting the new belt and hit a sustained 53mph (indicated) - tomorrow I'll take it out with my GPS and try it again.

Hopefully this belt wont wear out so soon this time.

If it doesn't then I think i'm going to tune the Dellorto a little more and also explore changing the gearing - I've noticed a gear tooth chart in the ModernVespa Wiki which I hope may point the way for me.

.

Great pics, and sounds like promising results!

Epic tread....great work. Thinking that it's time to pull the belt on mine now....

Ok, you seem to have the belt sorted (or getting there) how about the CDI? You can buy a higher quality, performance CDI but I've also seen people take the stock CDI and cut a notch in it and claim that it raises the max RPM or some such. Anyone have any feedback on this?

How about taking some of the packing out of your pipe?

.

Thank you for the nice comments - very much appreciated !!

Yes - I'd like to know more about the CDi mods you can do by cutting the wire in the CDi - there doesn't seem to be a definitive answer on whether this works on 2T models or whether its just 4T models - if there is anyone who can clarify this then, and also demonstrate where to cut then i'll give it a go!!

Re packing in the pipe..... its already come out, the padding was filthy and full of insects and goo and the such like.

.

.

Latest Update..........

Took the scoot out for a run last night (Thursday - very gusty weather - had to go carefully).

Came back home and changed the main jet to an 85, changed the needle clip position a couple of times (its now at the centre clip position as being the best position so far) and tweaked the slow air mixture screw until happy with it and then finally set the idle speed correctly.

Took the scoot out tonight (Friday - much better weather and hit 55mph consistently on a flat road) - took the GPS with me and it measured 50mph (see photo) so the speedo seems to be out by about 10% across the range which I think is probably pretty much the same for most Piaggio speedos as far as I can tell/have read. I went out in my car just after with the GPS, when the GPS read 50mph the car's speedo read 56mph so its sensible to accept that the scoot's speedo is comparable with most modern cars too (2010 Toyota Prius)

Since sorting out the rusty bits on the variator and rear pulley I've covered about 40 miles and I haven't noticed any slowing down of the top end speed as of yet so I'm hoping that I've solved this problem, I'll perhaps whip the variator cover off again over the coming weekend to see if I can see any fresh drive belt dust inside the casing.

.

.

So assuming that the variator/pulley problem is now sorted, there are only 3 more mods that I've got in mind to do at the moment.

1st one is to change the gearing, I thought about doing this with a Gear Up kit but having researched a little I'm not too sure that I want spend the circa £60 after considering that I've only spent £63 so far on all the other mods put together.

So I'm going to attempt changing the gearing by changing the profile of my rear tyre. To this end I've managed to "borrow" an new tyre (120/90) to offer up against the scoot to see if it will physically fit instead of the 120/70, and if so I'm going to get it fitted and give it a go, I'm not going to unwrap it just yet in case I've got to return it if it looks like it won't fit - photo attached of the tyre still in its silver wrapping - the kids said it looks like a space doughnut?? I'm going to have to careful that it doesn't foul against the tyre hugger and that the stand will still operate properly due to the new tyre dimensions.

Standard tyre is 120/70 10inch so tyre 'height' would be 120mm x 70% =84mm, the 120/90 10inch would give a tyre height of 120mm x 90% = 108mm, i think rolling tyre diameter would increase by 11% if I've done my maths correctly and the wheel/tyre diameter would jump from 422mm to 470 mm so an increase of 48mm (or 24mm each top and bottom).

.

.

The 2nd mod that I fancy doing is to get a fly-screen of some sort to deflect some of the wind away as I ride and to streamline me a few miles faster, I'm hoping this is good for 5 mph but I somehow feel that i'll only get another 2-3. However if I can get a screen of some description cheaply enough then i'm going to give it a go, new Vespa screens in the UK seem to be about £60-£80, but knowing me I'm not wanting to part with more than about £15 for one, so I might have to do some modding of something that isn't originally designed for an ET2/ET4, I'm guessing that most screens are fairly standard-ish and I'm quite good with a jigsaw and a dremel....... hehe.....

3rdly, my eye has been taken by 'exhaust wrapping' as a way to get a bit more power, I know this doesn't give a massive amount more power but when your'e dealing with a 50-70cc then every little helps. I saw it on a website for a race tuned go-kart and apparently it keeps the hot gases in longer so the power doesn't get immediately dissipated through the exhaust/front down-pipe, I've seen some of the tape quite reasonably priced and I don't suppose on a scooter exhaust I'd need very much of the tape to cover it.

.

.

Link to a video of a short run out on my scoot...........


.