Variator rollers & contra Spring

Harddog96

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Also found out why I’m hitting like 4000 before it takes off the Polini kit that I bought that’s the springs that came with an I put the yellow ones in an ounce for like 7000 that’s where my cruising idol is at half throttle. I think anyways.
 

DieselTech

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Also found out why I’m hitting like 4000 before it takes off the Polini kit that I bought that’s the springs that came with an I put the yellow ones in an ounce for like 7000 that’s where my cruising idol is at half throttle. I think anyways.
What gram rollers were you using to hit 9850rpm? Or what combination of things like springs, roller weights & contra spring?
 

Harddog96

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What gram rollers were you using to hit 9850rpm? Or what combination of things like springs, roller weights & contra spring?
I’m using the 28kg Polini contra, also came with a 22kg,
The rollers say 5,6 on them. But I have 6,7 as well.
And the blue Polini clutch springs. Which are the heaviest. There is yellow and green ones. Yellow is slightly weaker and blue is the weakest. Minus the stock ones.
 

Cannonball3

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One thing to consider is the belt. If its a tad short it may bottom on the driven before it allows the driver to totally up range. I found this out on the GY6. Longer belts were available at the time I was tuning mine. Doesnt take much. Look at the driven and see how far up the sheave the wear line is, should make it to the outer perimeter. This all assumes you engine is tuned and running properly. This is a vertical 70cc right?
 

DieselTech

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As Cannonball3 stated, check your old belt against new belt. I simple little trick to check your belt ride in the pulleys is to use a sharpie marker & paint your pulley halves with marker. Then go ride your scoot & see where sharpie Mark's have been cleaned off by belt.
 

Harddog96

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One thing to consider is the belt. If its a tad short it may bottom on the driven before it allows the driver to totally up range. I found this out on the GY6. Longer belts were available at the time I was tuning mine. Doesnt take much. Look at the driven and see how far up the sheave the wear line is, should make it to the outer perimeter. This all assumes you engine is tuned and running properly. This is a vertical 70cc right?
Yes I do. Also The whole thing the back bowling that holds my clothes and spins the belt it’s very wobbly and I’m pretty sure it’s what caused my belt that pinch yesterday and it turned my bike completely off when I was going down the road and stopped me teen guys know where to pick up another back pulley. or would it be better off just a switch out and spend the extra money and get an overange variator and CVT. It just sucks cause I just bought a brand new Polini variator.
 

Cannonball3

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I would advise a larger driven, be sure you get a matching belt. If your engine wont rpm out then. Look at tuning. I have no idea exactly what you are running engine parts wise. If your cylinder set is not basically matched to your pipe, it may not reach the pipes tuned band. Maybe some info on the parts you used?
 

Harddog96

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I would advise a larger driven, be sure you get a matching belt. If your engine wont rpm out then. Look at tuning. I have no idea exactly what you are running engine parts wise. If your cylinder set is not basically matched to your pipe, it may not reach the pipes tuned band. Maybe some info on the parts you used?
Stage 6 street race 70cc engine, polini high speed variator, polini clutch the one you can adjust easy. Also it came at 56 g rollers and 6,7 g I went ahead and purchased lighter ones just to see cause I’m only 135 pounds maybe 142 with all my clothes on. I don’t remember the brand of exasperates 10,000 RPMs just like the motor
 

Cannonball3

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Ok so what you are running is close to one of our Minarelli hybrids. Same cylinder and all. We are seeing low to mid 50s with around 10+k rpms. I dont know about the carb you are running. We are running a VM21 Mikuni or clone carb. It takes a fairly large carb to feed the fuel hungry Minarelli. What size is your carb? Is it stock? Try the heavier rollers for the heck of it.
 

Harddog96

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Local time
11:15 AM
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Iowa
Stage 6 street race 70cc engine, polini high speed variator, polini clutch the one you can adjust easy. Also it came at 56 g rollers and 6,7 g I went ahead and purchased lighter ones just to see cause I’m only 135 pounds maybe 142 with all my clothes on. I don’t remember the brand of exasperates 10,000 RPMs just like the motor
Ok so what you are running is close to one of our Minarelli hybrids. Same cylinder and all. We are seeing low to mid 50s with around 10+k rpms. I dont know about the carb you are running. We are running a VM21 Mikuni or clone carb. It takes a fairly large carb to feed the fuel hungry Minarelli. What size is your carb? Is it stock? Try the heavier rollers for the heck of it.
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