speedfight problems again

[jonny56]

have a speedfight 50cc a/c has leo vince tt on it i fitted a 82 main jet an its only doing 47mph and some times dose not accelerate properly

how can i improve the top speed and how come the bigger jet made no doffrence it did 47mph with the standard jet

[jonny56]

o.k now im gettin annoyed with this bike i have just fitted a polini speed kit with the variator an belt an its now doing 45mph even with a racin air filter it still does 45mph -.-
am i missin somet out?

[simon1221]

A bigger main jet does not neccesarily mean more speed

Did you set up the mixture settings correctly on the carb?
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DNA50 (sorry) ->> TZR125l >> GPZ500S

[jonny56]

nope duno how

[jonny56]

ok i fitted the standard variator back on it jut now an put the rollers outa my polini variator an its doing 50mph on the flat i just want to know why its going slower with the polini variator shouldnt it be going faster?
when i looked at the variator it had a black line in the middle compared to the standard one wich had it right near the out side of the variator. Is this were the belt is getting to? if so how can i get it so the polini one is working properly i have the polini belt but my clutch is standard
thx for the help

[simon1221]

When i had my scoot, i didnt know one end from the other (in a way), so i have no scooter knowledge, however have a quick browse on this forum (clicky clicky), and see if it has any useful information.
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DNA50 (sorry) ->> TZR125l >> GPZ500S

[Kye]

Black line is where the belt wore a groove when it was restricted, bad for performance, will give you a lag at 30mph

Fit the polini variator back on and try 1g heavier that what you have in.

Unless you have an open filter, just put a 72 main jet back in the carb otherwise you will be running rich, check the plug after a good run and it should be a golden brown colour.

Rollers is a fine art when tuning scooter transmissions, its very hit or miss unless you know what you are aiming for.

If it picks up really quick, in the 0-10mph range, then feels like its revving its nuts off and not picking up as quick in the 10-35mph range, then your rollers are probably too light.

If it picks up smoothly until 10mph when it gets accelerates hard, then you usually have the rollers spot on around there.

Roller tuning is hard to explain online, I've only learnt by experience really.

I think my friend was using 7.2g rollers with a LeoVince ZX, so you could give that a try? Not sure how it'll respond with a Leovince TT though
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Ducati 600SS
Vespa PX125

[jonny56]

i was running it with 7.7g rollers in an it accelerated like mad to about 20 then it started dieing down the kit came with some 10g so ill give them a blast cheers will have to wait a while tho got a big thorn in ma back tyre now lol brand new tyre aswell get it back on friday tho so will ave all weekend mess round wid it might order some more rollers cos scootercenter sent me the rong ones they sent me the yamaha ones witch are slightly smaller so will order a set of 8g-10g rollers (hopefully give me the right size dis time)

[Speedy2]

i have also had all these probs with my speedy 2 Ac, its got a vinci zx n i have also wasted 60 odd quid on the Polini Variator kit. But!!!! i have found a use from the polini....wat i did was use the 7g rollers which came with the pipe n put these in polini variater then i "bodged" the rear pully off the standerd variator on. once i put it all bak 2gever it did an easy 55 on a flat n melted the speedo needle down hills!
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The L plate Worrier! Apparently?

[jonny56]

did you use the frount part from the polini and the rear part that slides off the standard one?
i have the rollers wieghts correct at 7.8g but the bike only doin 42mph ill wait for a reply if thats what you did speedy ill give it a go

[jonny56]

doesnt matter ive done that and its running good now i got to 51mph and had to slow down because i caught a car up BUT i now have a problem with my engin casing some 1 musta over tightend the bolts and has recked the thred in the case. My dad said he will drill them right through though and put a bolt throgh and a nut on the end have to wait untill the weekend to ride it now thx for the help tho guys

[Speedy2]

Yeh u've got to watch those lil B****D bolts on the crank case.....funnily enough i only have 2 holding mine on and 1 is a bolt rite through with a nut on the end (must be sum sort of French joke) . Just re-jetted my speedy it had the 72 main jet in and i put a 74 Because scootercenter where out of 76's but its got sum beef now
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The L plate Worrier! Apparently?