Clutch/engagement question

[dwhst9]

This is about our 90 2-stroke. Just installed 54mm kit. Clutches are stock w/ 4.8g rollers, ZTR 1500 spring and 2000 springs. The quad seems like it's stuck in 1st gear. It revs up and takes off but doesn't accelerate. I tried 1000 springs and it didn't make a difference. Should I try the stock rear spring? BTW, we've got a Hetrick pipe.

[dwhst9]

It's REALLY hard to push the belt down into the rear pulley...if that is useful info? I've got a stock Polaris belt.

[bignasty]

too much rear spring i think change out to a koso 1500 or ztr 1000. the ztr 1500 is closer to a koso 2000 slip off the rear tube that is on the pulley and grease the shaft the collar and spring ride on should open up real easy when the torque is off if you have a rpm gauge see where your clutch is engaging might want to use 5.0 or 5.5 gram roller too see what happens:)

[dwhst9]

Originally posted by bignasty
too much rear spring i think change out to a koso 1500 or ztr 1000. the ztr 1500 is closer to a koso 2000 slip off the rear tube that is on the pulley and grease the shaft the collar and spring ride on should open up real easy when the torque is off if you have a rpm gauge see where your clutch is engaging might want to use 5.0 or 5.5 gram roller too see what happens:)

Can you explain in more detail what you are referring to about what to grease?

[bignasty]

the collar is behind the torque spring that is attached to the rear pully. You kind of have to wedge it out with a couple of screwdrivers because there a two o-rings that dont let the grease get on the clutch and the bell. Hope this helps:) :)

[Reimer Racing]

Try installing 6 gram rollers. You have too light of front roller weight. Need more roller weight to pull the belt down in the back thus more top speed.

[LT80]

yep, more roller weight will be part of the equation, but it sounds like the torque spring is too stiff.

[dwhst9]

Originally posted by Reimer Racing
Try installing 6 gram rollers. You have too light of front roller weight. Need more roller weight to pull the belt down in the back thus more top speed.

So the heavier roller weights will close the variator faster, making the belt ride higher up the variator, which in turn pulls the belt further down inside the driven clutch?

What CVT setup would you guys recommend for trail riding with this combo? 54mm bore, stock stroke, 24mm carb, Koso intake with red insert, Hetrick pipe, stock variator & clutch, stock gearing.

[dericsdad]

What size sprockets are you running???

Try 5.5 or 6 gram rollers. The koso or ztr 1000 torque spring might work better for you if you are only trail riding. You'll just have to experiment.

Keep in mind, like you said, a stiffer torque spring will make it harder for the belt to push the rear clutch sheeves apart, and therfore will build up a lot more heat. Something you don't want for a long trail ride.

[LT80]

Ahh, no porting.
The torque spring is way heavy.

[dwhst9]

The cylinder is ported. I may buy an assortment of rollers to try. I'm getting a 1000 spring from dericsdad.

[dwhst9]

Originally posted by dericsdad
What size sprockets are you running???


Whatever stock was. I'd have to go count the teeth.

tell me what sizes you want ill send them to you then you will know what to buy just trying to help I have from 4.0 thru 7.7

[dwhst9]

Originally posted by tgcheeseman
tell me what sizes you want ill send them to you then you will know what to buy just trying to help I have from 4.0 thru 7.7

Since you ran this topend kit, what was your CVT setup? I can't do anything until I get another clutch bell nut :huh

I ran 5.5 rollers 1500 koso ans 2000 fan springs. /reat combo for us.

[weldr383]

just curious,how did you screw the nut up?

[dwhst9]

Originally posted by weldr383
just curious,how did you screw the nut up?

From removing/installing a bunch of times with impact wrench (on low torque setting).

[airmobile101]

Originally posted by dwhst9
From removing/installing a bunch of times with impact wrench (on low torque setting).
lol, your not the only one!

[etondaddy]

That's why I had one.........I still have two more in the trailer.


Mike Kozura

[dwhst9]

I made a couple test runs at lunch time today with the following setup:

4.8 rollers, STOCK torque spring, 1000 springs.

The quad sort of hesitates for about the first 10ft and then all of a sudden it screams like a bat out of all the way until it tops out. Definitely seems like a CVT setup issue and not anything else.

I think with heavier rollers and a stiffer torque spring, it will get rid of the hesitant start.

I marked the variator and the belt stops .15" from the top of the sheaves.

[JAG Motosports]

The bog comes from it shifting into second to quick. You need to go lighter on the rollers or heavier on the spring. I would go with a slightly heavier spring. What brand of 1000 spring do you have now?

[dwhst9]

Originally posted by JAG Motosports
The bog comes from it shifting into second to quick. You need to go lighter on the rollers or heavier on the spring. I would go with a slightly heavier spring. What brand of 1000 spring do you have now?

The original OEM spring. I have a ZTR 1500 that I am waiting to try again until my heavier rollers arrive this week.

So are you happy with that motor dave

[dwhst9]

Originally posted by tgcheeseman
So are you happy with that motor dave

Yes, it's a HUGE improvement over the tired stocker :cool:

[bignasty]

don't go too light on the rollers. If you run long tracks or your boy is on the gas alot, you could burn the belt and melt the rollers. kkep an eye on your heat buildup on the variator.:) :) ;) :) :)

[dwhst9]

Originally posted by bignasty
don't go too light on the rollers. If you run long tracks or your boy is on the gas alot, you could burn the belt and melt the rollers. kkep an eye on your heat buildup on the variator.:) :) ;) :) :)

We trail ride and drag race, no motocross.

[etondaddy]

Hey Dave if you guys aren't doing anything Sunday there's a race at Steel City in Delmont.



Mike Kozura

[dwhst9]

Originally posted by etondaddy
Hey Dave if you guys aren't doing anything Sunday there's a race at Steel City in Delmont.



Mike Kozura

That would be fun. However, Hayden's 1st communion is Saturday. We're going riding at Tri-County on Sunday.

[etondaddy]

Originally posted by dwhst9
That would be fun. However, Hayden's 1st communion is Saturday. We're going riding at Tri-County on Sunday.
Kyle can't wait for Steel City it's one of his favorite tracks. We raced there once this year all ready.


Mike Kozura

http://i58.photobucket.com/albums/g278/etondaddy/Race%20pics/300ex%20pics/100_2534.jpg

http://i58.photobucket.com/albums/g278/etondaddy/Race%20pics/300ex%20pics/100_2529.jpg

[bulldogfallon]

You have to know a few things about your set up before any advice can be helpful to your problem.


1st question--What rpm do you want you clutch to engage at in regards to where the engine makes its power---Once this is determined then set your clutch stall according with the stall springs(other factors also effect your stall though)


----What belt are you running? A longer belt can sit higher on the rear pulley giving you more stall (ratio of front pulley to ratio of turns on the rear pulley)


2nd---You need to have a fair idea of what torque spring and roller combo will work (this is done by knowing the pipe and engine characteristics--is it a torque set up...high rpm set up????)

The ZTR1500 is not too heavy of a spring for your set up....we will use that in a stock 90 without an issue...


You need to run with cvt cover off (not riding)and see where the belt is located on the rear pulley when the clutch engages---if the belt dives too early then your quad is shifting before it moves (not good for launches and is exactly what your last post described)

How do you fix? Either low clutch engagement rpm or add a stiffer torque spring or lighter rollers (if the set up isn't close to being right)to hold the belt up higher longer.

After this is all done then you can start to check for belt travel....


I am curious as to what belt you are running...if it is not at least a 787mm in lenth it may not be ideal for your set up.


If you figure out the above items I am sure you will be much better off..



---What happens often----more stall is added to get over the soft launch...like over revving your car in second gear....well it can mask an issue, but it will lead to heat and slipping which reduces the life of your cvt and parts and your forfeit reliability.


Hope this info helps....

[JAG Motosports]

:eek2: ^^^ now that's some heavy stuff. my head is still spinning:tired: must be a focus thing, do you have the cvt for dummies version?:ermm:

[cik orange]

hey Gary sounds like you've been doing your homework I'll give you an B+ the score would have been higher if you would have given your personal number cause he'll need to call you.

Isn't CVT'S FUN

All kidding aside that is very good advice

[dwhst9]

I ended up using 6g rollers and a KOSO 1500 spring with 1000 fly springs. He's getting good low-end torque & top-end speed. With this setup, it launches hard enough to pull the wheels, but not hard enough to flip over. We went on a 4 hour trail ride yesterday and it performed perfectly. Thanks for all your help!

http://www.postimage.org/image.php?v=aVgJzI0

[etondaddy]

Where's that at......... Looks like Mouintain Ridge



Mike Kozura

[dwhst9]

Originally posted by etondaddy
Where's that at......... Looks like Mouintain Ridge



Mike Kozura

Tri-County ATV Club near Indiana, PA.

[etondaddy]

That's right you did tell me that.



Mike Kozura