Speedfight 2: Have I Derestricted It Correctly/What Rollers?

[Inked]

Hi Guys

I thought i would have a go at de-restricting my speedfight 2 and just wanted to check with you guys to make sure I've done it right.


I watched this guide:

https://www.youtube.com/watch?v=2XSw28XJeFg


But when i took the variator off there was this washer behind it:


https://i59.tinypic.com/jv1wqu.jpg

https://i58.tinypic.com/ne81hk.jpg



Am i right in thinking i leave this one on as it seems like its there to stop the variator rubbing ?




Also the veriator looks a bit different to my one:

https://i57.tinypic.com/28jllk6.jpg


Am i meant to take this back plate off:

https://i58.tinypic.com/24zvdec.jpg

To leave this:

https://i59.tinypic.com/20b1tna.jpg

Then just refit it?



One more thing (sorry)....


While i had it all apart i noticed that all the rollers were more of a hexagon shape (lol) so i want to replace them.

The scooter has the standard gurtner carb....etc but has a viper exhaust.

I know rollers are a bit trial an error but do you think i should be ok (good top speed and acceleration) with some 6.5gm rollers or am i way off ?



Thanks guys

[evoboy]

Firstly...Clean all that dirt buildup out of the gearbox case.

The washer is meant to be there and in NO WAY has any effect on the restriction/ variator movement.

The back plate on the variator I would normally remove. Minarelli and Piaggio engines dont use this back plate and operate fine.

Roller weights depend on your weight aswell as the carb/cylinder/pipe setup. I would start with 5g rollers and try it at that.

Put a new belt on it also. If the old one is worn, it wont travel all the way up the front pulley.

Oh, and usual stuff about derestriction at 16 being illegal etc.
____________________
Suzuki GT250 x7------- Fazer 600------CB250RS------Aprilia Rally 70----- Bandit 600

APT Motorcycles

[Inked]

Thanks for the reply

Yeah i couldn't believe the state of it in there, I've not long had the scooter and this its the first time I've taken the cover off.


Like i said, its all pretty much standard 50cc cylinder , standard carb with a 75 jet (i think). The only thing that's been changed is the exhaust, and that a viper exhaust.


I think some exhausts come with a roller set but i can find what ones come with the viper.


Yeah i was going to change the belt anyway as i doubt the previous owner ever changed it.

Will a standard belt be ok or do i need a better one ?



I was going to put this but then deleted it before posting the thread....lol

I'm not a teenager trying to create a miracle 600cc pocket rocket, I have a full car and bike licence and drive an audi turbo car. this is just a cheap run around....lol. i can show proof for all this to a mod if necessary

[evoboy]

[Inked]

Thanks mate

I'm just trying to put a little shopping list together.


The standard jet was 72 and it was up-jetted 76 after the exhaust was fitted.

Do you think it should have been bigger?


From what I've been reading, people seem to say the 6.0 rollers are good after fitting an exhaust on these but as you say i should try 5.0 what do you think about going 5.5 (meet in the middle...lol) and going from there?


I'm just looking at belts and I've come across an Endurance one and a MKX Kevlar Racing one.


Are any of these any good?

[Inked]

Do you think i should get the 5.5g rollers and MKX Kevlar belt and see how i go?

[Inked]

Right I've been doing a bit more reading........


I'm going to try some polini 5.6 gr rollers and see how I go but I'm stuck on what belt to get.

It seems that kevlar belts aren't always a good thing.

What belt would you guys recomend out of:

Polini standard.

Polini kevlar.

Athena standard.

Athena Platinum.

Dayco standard.

Malossi special x.



I've been reading good things about the Athena belts but I don't know if they are talking about the standard or the platinum ones.


So what do you recommend guys ?

[mentalboy]

Can't help you with the belt situation - but I'll bet it's mostly preference and teenage willy waving that decides which one is the best.

As for the rollers I have three small but crucial words for you. 'Trial and error'..
Once you start tweaking these 50's even your weight can make a difference with the rollers (obviously depends upon who sets it up and just how different their weight is to the rider).
Personally I'd start with a weight fairly close to what you had in there (i.e: no more than 1/2gram more or less) as presumably it ran ok before? 1/2 gram either side of the set-up you're happy with can make the difference between having to do a running start but having a good top end to pulling off the lights like Rossi and running out of steam before you hit 25mph.
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Make mine a Corona.

[Inked]

Thanks mate


I don't think these rollers have ever been changed but can't seem to find out what rollers are fitted to these as standard

[mentalboy]

I doubt if it's much help but the Haynes book of lies tells us that a Speedfight 2 has.... Brown 19mm rollers, not yellow or black but brown???? (Bout as much use as a fart in a hurricane)

Depending upon how badly they are worn I'd gather up said old rollers, take them into the kitchen and stick them on a nice clean set of digital scales. Note the weight then divide by number of rollers (Six if my memory serves correctly!) this will give you an average of what's left for each roller. You are unlikely to want to go below this weight.
(Then take the least knackered looking roller and weigh it. If it is significantly higher than your average weight go with the next heighest weight)
The advantage of weighing together is that it gives a more reliable figure than just weighing one - unless you happen to have a nice set of dope scales about your person! - as kitchen scales aren't too accurate for very low weights.

Forget about what was in there originally, with different exhaust, jets and God only knows what you need to use the rollers you've got as a baseline.

Edit: Also remember that some ped bois will use two different weights of rollers to get the balance to their liking - this probably causes faster wear as the heavier ones will not be thrown out as quickly as the light ones and I wouldn't recommend it.
____________________
Make mine a Corona.

[Inked]

Thanks for all the advice.

To be honest the scooter is a bit slow pulling away but that could be down to the shape of these rollers.

Does the manual you have say what weight rollers are in there as standard?


Most sites recommend using 6gm rollers.

[mentalboy]

Nope. That'd be far too useful.

Every bike is different depending on what bits have been messed with. Forget the standard ones, it almost certainly won't be those, (unless by some fluke of nature...)
____________________
Make mine a Corona.

[Inked]

[Inked]

I've just found this chart showing the standard roller weights:
https://www.beedspeed.com/html-pages/variator-roller-weights-chart.htm


According to this the standard weight would be 9gm but that seems way too high.

Also I'm sure I'm meant to go down on the weight after fitting a performance exhaust.

[stevo as b4]

Kevlar belts did not work for me on the 100cc. They were all wider than std belts despite instance that they were correct for the machine. They are also too stiff and in my case stopped the variator from getting to it's lowest gear setting.

Std belts reduced the flat spot and made it pick up from 10mph, instead of 15-20mph before, but the best thing I ever did to get it to pick up was to have the head face machined 0.6mm, to up the compression close to 7:1 if I remember correctly? The head design is very shit on the 100cc with a poorly shaped combustion chamber and no squish band at all. A custom machined centre plug head with a correctly machined squish band would probably make a massive difference even at lower compression ratio's.

back to the belts, I found just under 12bhp was chewing them up pretty quickly. Maybe I did not have the right transmission set up or torque spring fitted? I never got more than 2000km from a belt, and had one snap at 60mph locking up the back wheel once too.

My only advice unless your told different from a scooter tuner is to run a std belt and variator, and just play with roller weights, clutch springs and jetting to get a good set up and bog free take off.

I'd need to be convinced that the Malossi variators actually make any improvement, as I found it caused more issues, that I didn't have with the std set up, though I never kept changing things around to try and solve my problems.

[mentalboy]

And that ^^^ highlights why looking at standard rollers is not necessarily the answer to your problem.

Lad goes in, fiddles, decides to skim head. Even if you started from scratch with new OEM exhaust, jets, rollers, variator, belt and spring you'd still be left with a higher compression because of the skimmed heads and a combination of nice new parts that work best at a lower compression.


I'll say this next bit (again), slowly:

--Weigh - your - old - rollers - or - get - them - to - a - mechanic - who - can - weigh - them.

Then, - because - they - are - worn, - use - the - next - higher - weight - or - ask - the - mechanic - to - fetch - the - most - suitable - weight - for - the - junk - he's - just - weighed.
____________________
Make mine a Corona.

[evoboy]

The reason 2 different weight rollers are normally used is to fine tune the RPM range. Its only meant to be temporary as once you are happy with the RPM's you change to that weight.

Its not as easy as just telling you what weights to use.

Belts dont last a race day on my race scoot. 17bhp eats them pretty quickly!

Most standard scooter engines have a rather large piston to head clearance. It makes a noticeable difference when reduced.
____________________
Suzuki GT250 x7------- Fazer 600------CB250RS------Aprilia Rally 70----- Bandit 600

APT Motorcycles

[stevo as b4]

Interesting info there Evoboy!

I was checking and often changing belts every 1000-1500km after the scare I had with the snapped belt, and all that time I was just thinking I was another have a go home tuner that did not understand exactly how to set up an auto transmission or what parts I should have been fitting, hence the belt snapping at what I thought was a low mileage.

I probably shouldn't mention on here that the first time I took the machine out with the high compression head I decided it needed, I holed the piston and had to re-build it.

After that I was using a plug two grades cooler, filling up with 97-98RON and I went one size bigger on the main jet, all to try and stop it happening again, but without really knowing what it needed to make it reliable with higher compression. It was all guessing on my part.

There was a huge piston to head clearance on the std SF100 motor, and even with 0.6mm removed from the head face, and checking with no head gasket fitted, I still had about 1.5mm clearance, and the head gasket added another 0.5mm to that!

All said and done, if I was messing with the 100cc Pug motor again, I would use std Variator, and probably the std carb too. The exhaust, air filter, and the high compression head was IMO all worth doing, and if an adjustable race type clutch could have been made to fit, id have used one as well.

Biggest fail for me, was that even after set up and dyno tuning, I found a Piaggio NRG Mc3 with an after market pipe and jetting/roller weight changes, to be as quick up to around 45mph!

[Inked]

Thanks for all the replies, you've definitely given me more to think about /look in to



I do have another question about replacing the rollers but I'll leave that for another thread.

[RodYork]

I was recently working on a Speedfight (water cooled)
I bought a pack of different weight rollers & changed the belt.
It is a lot of trial and error as others have said (evoboy)- especially if the bike has been tampered with prior to you.
I got a recorded 65mph from it- there is a company called PedParts? that were really helpful- think the guys name was Ricky?

[Inked]

A bit of an update......



I changed the rollers for some 6.5g (the ones in there turned out to be standard 9g) and fitted a new belt (the new belt was quite a bit wider than the old one).

I then took it out for a test ride and it was revving up fast and was like it was stuck in 1st gear.

So I brought it home and put the old belt back on an that seemed to allow it to change gear but it still didn't feel right.

Someone suggested that if the carb had a 72 jet in there as standard and it has a performance exhaust then I should have a 80 jet in there, so I gave that a go but it still didn't feel right.


I then put the standard 9g rollers back in and it's now running a LOT better (almost perfect).



The only problems I have now are that pulling away is a bit slower (probably down to the heaver rollers) and the top speed seems to have gone down as it's only showing about 40mph on the clock at a push.




I thought a bigger jet (that's all that changed at the moment) is meant to help with top end speed not slow me down ?

[andyscooter]

bit late now but oe belts always last longer then aftermarket ones
____________________
gilera runner vxr200 (chavped)
if its spelt wrong its my fat fingers and daft auto correct on my tablet

[evoboy]

The torque spring in the rear pulley is way too stiff.

It needs the heavier rollers to counteract the stiffness of the spring.

All it is doing is putting unnecessary load on the already low powered engine.

Changing the main jet wont give you more top speed.
____________________
Suzuki GT250 x7------- Fazer 600------CB250RS------Aprilia Rally 70----- Bandit 600

APT Motorcycles

[mentalboy]

Without doing a lot of work you will trade off take-off speed against a faster top speed.
I'd imagine that long before you attain moped nirvana you will have accrued a mass of new parts that will be needed for trial and error. Just one of the joys of these little auto nightmares!
____________________
Make mine a Corona.

[Inked]

Thanks for all the replies guys

It actually had an OE belt fitted (the one I was replacing).


The torque spring is the standard one and I don't know how stiff the standard ones are.


The reason I mentioned the main jet and top end is because now I've put all the old parts back on, the jet is the only thing that's changed and now my top speed has gone down.



I know its hard to believe with a scooter of this age...etc but everything apart from the exhaust is standard.