Bike Reaches Higher Top Speed When Spiked

[diynuke]

Sound's to me like an sticky rear pulley.

This is what I think happens: So it revs up and moves a bit then get stuck and when the rpm's are high enough it will shoot loose and move the remaining width. which would explain the sudden drop in rpm.

And personally I would like to run an 72cc at 7500/7800 rpm when accelerating. but that's just a matter of taste.
and for the torque spring. you want to have the lightest spring on there that will work without slipping. and to that you will tune your variator. I see the torque spring as an tension spring so the stronger it is the heavier roller weight's you will need. so I would say keep the stock torque spring if you have slippage problems (indicated by black mark on the variator because of slippage) then you could go with a stronger spring.

But first thing to do Is check the rear pulley. If you never disassembled it it will probably will be a pain in the ass. especially the sleeve under the spring.
Let us know if that was the problem. pretty curious about it ;D

[diynuke]

Aug 9, 2018 22:16:42 GMT -5 magoconnor said:

I have managed to pull some more rpms.

Of cause the increase in rpms will wear down the engine faster, but what is the save zone?
Would it be okay to hit 9000 occasionally?

sometimes sure. but the engine is at the redline. so just as in a car. the engine would survive it but it doesn't prefer to run that hard.

[magoconnor]

Okay thanks for your input.
I have disassembled the clutch a good many times, and it's not long since I re-greased it.
But it may be time to lube it up again.
The grease always seems to leak out a little, do you know a cheap fix?
The o rings are new.

I have change the stock torque driver, for one with a straight groove.

[diynuke]

Aug 14, 2018 15:38:34 GMT -5 magoconnor said:

Okay thanks for your input.
I have disassembled the clutch a good many times, and it's not long since I re-greased it.
But it may be time to lube it up again.
The grease always seems to leak out a little, do you know a cheap fix?
The o rings are new.

I have change the stock torque driver, for one with a straight groove.

Well you have special grease for that application.     for example malossi MRG

and for the cvt it has to be something that isn't moving the way it should.  otherwise I wouldn't know a way to explain why it would drop in rpm so suddenly.

[magoconnor]

Yes I also use that stuff.
I will pull the cover, but the bike seems to be riding fine other than the drop.

[diynuke]

Aug 14, 2018 15:47:33 GMT -5 magoconnor said:

Yes I also use that stuff.
I will pull the cover, but the bike seems to be riding fine other than the drop.

Use less I guess xD

And well there is 1 rule of thumb.   If it aint broken don't fix it 

[magoconnor]

Yeah It would just be cool If it would pull more steady, instead of dropping off.

[magoconnor]

The problem seems to be getting worse...
the Rpms now drops down to 7000, and have hard time recovering.

[diynuke]

Aug 15, 2018 12:05:41 GMT -5 magoconnor said:

The problem seems to be getting worse...
the Rpms now drops down to 7000, and have hard time recovering.

Could you film it? or just a good sound recording. (a video tell's a million word's)

And is it a smooth transition like in an auto gear car.

or it is really rapid

And have you tried the stock torque converter again? 

[magoconnor]

Hello again.

I pulled the damn cover off, the clutch was dry as a bone.....
Gave it a special treatment with the grease, appears to have fixed it

Thanks for your help.

[jeff84]

that just your cvt doing its job. I would be happy with those results. you don't want it to sit at redline all the time. you might have already said but I missed it. have you done the sharpie test. marking the variator to make sure you are getting full belt travel? I would guess now you are but probably were not with the heavier rollers.


oops I just posted that without realizing there was a second page