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@wraggy111 avatar
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Vespa GTS 125
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@wraggy111 avatar
Vespa GTS 125
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Hi All, I have a carb 2009 GTS 125 with a polini 9 roller in it it has 5.5 weights in please can anyone tell me the best weights for it it's seems to revy it also has a pm62 exhaust and a polini sports clutch. Thanks Andy.
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LXV 150 3v ie. Midnight Blue (Sold) Now Honda Zoomer X
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Difficult because we don't know if it also has an optional Polini blue spring in the driven pulley assembly.

Buy a cheap tacho/hour meter to find out what the revs actually are.

Is it still doing 80 mph?
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@wraggy111 avatar
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Vespa GTS 125
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Vespa GTS 125
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Hi
No it's about 67 now
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LXV 150 3v ie. Midnight Blue (Sold) Now Honda Zoomer X
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Difficult as i have no direct GTS 125 experience. Stock weights are 7.4g so Polini with 9 weights should be around 5g if all else is stock. (7.4 x 6 = 44.4. 44.4/9=4.93) If you have a difference counter spring then all bets are off!

Maybe the belt is worn and thinner than recomended? That would give you a lower top speed. But maybe not 13mph less. Depends on how many miles/kilometers the belt has on it. Edit:- Stock belt is 22.5mm wide. Low end tolerance is 21mm.

Having a tach/hour meter would give you real rpm numbers. But you'd have to feed the signal wire down from the handlebar and wrap it around the spark plug lead.
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Molto Verboso
S150 '09, Beo 500ie '08
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Once you start fiddling with the transmission and exhaust components it becomes very difficult to know up front what the "best" weights should be. Everything between air box and exhaust is a tradeoff and when several components are modified the tradeoff is difficult to predict. I suggest buying a cheap Chinese set of tuning rollers (several sets of rollers with various weights in 0.5g intervals) and fiddling around until you find the weight you like, then replacing them with a better set.
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