Variator issue, horizontal minarelli

[ninjarelli]

Hi.

Have an issue with my Malaguti Centro 50cc with the horizontal Minarelli with Ducati ignition, same as Beta Ark etc.

It does not shift in the variator, bought a Stage6 Sport PRO variator and a STAGE6 SPORT PRO clutch + a new Division rear torque drive.
Tried two belts, one shorter STAGE6 (PRODRIVE) (736X16,6 MM)and one MOTOFORCE (RACING) (750X16,5MM).
Used the Medium Stage6 torque spring and the included medium springs for the clutch.
Tried different variator weights, 4.3g, 5g, 6g.
Does not shift and only the inner bit of the variator is used in the front.
Cylinder is a Stage6 Cylinder Kit 70cc Streetrace cast iron Minarelli horizontal AC, there is compression, it starts no problem.
Division carb (PHVA 17,5 Replica) with an 86 jet.
It moves forward at rather high revs, but not fast at all.
Any suggestions?

[aeroxbud]

What exhaust have you fitted to the bike?
How do the belts you have compare in size to the original? The size of some belts is different to the actual length.

[ninjarelli]

It's a Stage6 PRO Replica Exhaust.
Original belt is 754X16,5

[aeroxbud]

You will need stiffer clutch springs. I had the same cylinder and exhaust years ago. It needs to be set-up for at least 9000rpm to be in the power band.
You need to physically compare the belts side by side. They can be quite a bit different in length to the stated size.

[ninjarelli]

Will try stiffer clutch springs, it just says Medium on the ones i have

[ninjarelli]

Tried a Polini hi speed variator kit, changed to the included stiffer clutch springs. 5.6g variator weights. Still revs but slow. Softer torque spring needed?

[ninjarelli]

Looked at the parts and realiazed that i don't have that washer circled in red, could that be causing it?

[aeroxbud]

If you have replaced the variator, it will come with its own drive boss. You would need to shim it if it is too short.

[oliver]

Almost sounds like the torque driver is stuck closed. Does it operate properly when you open up the rear pulley by hand?

[ninjarelli]

The Polini variator came with a drive boss, it is has a thin shim and everything lines up good.

I can move the torque driver by hand when i mount the belt, no problem there

[ninjarelli]

Now it's moving, just had to find a long straight, slow of the line, but once up to rpm it moves.
Contra spring does not matter polini 22kg or 28kg.
5.9g polini variator weights from the hi speed kit.
Don't have any lighter weights but maybe needs even lighter?
Clutch springs is the blue from the polini hi speed kit.
Thought i had the carb in the ballpark but on half throttle nothing much happens, full throttle it hauls.
Any tips?

[aeroxbud]

You probably need lighter rollers for the exhaust. The stage 6 replica makes peak power from about 9,000-9,750rpm. That's the range you need to be in.