Variator Problems - Causes

[WISH1965]

My Q is this, what causes the rollers in the variator to hang up? IOW's the variator is hung up and it causes the quad to act like it is stuck in high gear. This cost us a race win this past weekend. The rollers were two races old. It is a Yamasida variator if that matters. The rollers were "flat spotted" & I have grooves etched in my variator. What causes this? Advice please. Thanks.

WW

[Logan #34's Dad]

All rollers are NOT created equal. The best roller on the market are made by/for Dr. Pulley.
If they are flatsided then your creating too much heat. Which means your cvt set up is off. It may be a rocket for a couple of laps or at the start but as the heat builds it will fall off and eventually fail.
Where is the etching or grooves located on the variator? If they arre on the face then its time to replace it.

[Coley'sdad#8]

Rocky is correct there but also check the bronze bushing in the middle of the variator to make sure it is not loose and sliding in and out of the alum housing which will cause it to cock sideways and hang variator. And the 3 slides also.

[WISH1965]

does not appear to be any slop in it?

[Coley'sdad#8]

well if the variator is working correctly then like rocky said you are making too much heat either with a worn out torque spring or incorrect setup. List motor size, upgrades, gearing, tire size, type of racing and the name of your first pet and we can get ya pretty close.:D

[WISH1965]

DRR 70
2000 lbs spring (2 races old) MX
rollers (3) 4.5 (3) 5.5
16" snow hogs
32 rear sprocket 17T front

I am going back to the 1500lb spring
rollers to start 3.25 -3.75

Pet name: cannot remember, probably irrelevant to the problem??

[jerkyboy]

You running in a bull ring. Id granade a motor in one lap with that setup. You need bigger rear tires no less that a 18" snowhog.
throw away that 17 tooth front sprocket. put the stock 19 back on. If the face of the variator is getting wavey then that could keep the belt from dropping back down. Put a new variator on it
and you should be close with the 1500 and rollers you listed.

[WISH1965]

my bad, the snow hogs are 18 but measure out just over 16" should have been more clear on that. The front sprocket may be 19T, I'll check for sure, it's one that has the slipper sprocket, may be 19T, I could be thinking of the 17T on my 450R? Thanks Mike.

WW

[jerkyboy]

If its a drr slipper sprocket its a 19. Change the variator the groves in the face make the belt hang up. With these 70s nothing lasts for more than a couple races.

[WISH1965]

Thanks. These things are a money pit!!!!!!!!!!!! I really wonder why I am racing these things??? It's always something. I keep telling myself, it's because junior wants to race. One other sound off item....I hate these CVT's. It's constant agg.

Again I'll stop whinning. Thanks.

WW

[mydirtkids]

Hey Wish, I know how you feel. Go ahead and vent!!! Get it out, really there is no other way:mad: . I was the same way when we first got into the CVT world. Once I figured out most my problems were due to a lack of knowledge on my part life was a little less stressfull. Once you start to figure these things out, they really are a lot of fun... still expensive.

Good luck to you, the folks on here will save you a lot of unnecessary expense. Hopefully you can keep the rest of your hair (if you have any left)!

[WISH1965]

Yeah I'm starting to figure them out, but still it's always a learning curve. You solve most of the problems by spending $$ to replace the problem areas. We're getting there, but it's always something, whether its a craked frame, trans gears, etc. Cannot wait until next level to get away from these CVT's and into the Japanese products!!!!!!!! Yeah they break as well, but far less often.

[Logan #34's Dad]

yeah, you've definitley need to change sprockets. Snowhogs suck!If your not into the bigger tires then get yourself the new douglas tire.

[WISH1965]

will get over the Winter 18 x 8 x 8 Douglas or rumor has it Maxxis may be coming out with something, but at this point I will wait until Winter when these things become available. Finishing the season with what I got.

19T 32T sprockets for the snowhogs appear to be fine.

[brianjlinke]

been hearing good things about new yamaha 125

[WISH1965]

I hear ya Brian. I should feel fortunate i haven't had to go through the agg you've gone through recently. Per our conversation Saturday after the race, you & Joe were correct with your assumptions, it was flat spotted rollers etc. Might take you up on that $150 offer :(

This nickle & dime BS is driving me nuts, just wanna race, get my kid track time & it's always something, no matter how well you go over these things. I'm turning gray reeeeaaalll fast!!!

WW

[mydirtkids]

Yamaha 125 should be on my dealers floor this week... That is going to be a tough one to race though. Kinda a weird class, not many pitsters or 125's running right now. Speaking of running, I have watched a pitster for a while, and they really seem to have more issues than the CVT's... Just not sure how the Yamaha would do. JMO not wanting to pick a fight...

The CVT is out, poked and prodded. I think the setup is good to teach the kids how to handle a track and the other riders. The CVT lets the kids just ride without confusing them with gears...

[mydirtkids]

As to your rollers, WISH, we have gone with an overrange kit. When we were using the smaller rollers, I had the same issues you are experiencing.

What worked GREAT for us on MX was:

Dr. Pulley variator (if you choose to stay with the 787 belt)
Dr. Pulley 3.75 or 4.0 rollers.... STAY AWAY from the stage 6 roller
Drilled out the CVT cover (rear), took out the yellow variator filter and purchased an outerwear for the CVT.

ALL our roller/variator problems went away... BTW we are running a 2010 90, but the guys here with the 70's ended up doing the same

[Coley'sdad#8]

Grasshoppa, you have to keep it cool and let it breeve.

[WISH1965]

Run it through mud to keep it cool......that's the secret :)

Seriously though, looks like lots of holes. The cover on this quad does have to go, does not have any breathers.

Did you just cover the area with duct tape or is that a sheet metal panel etc.? Cannot quite tell from photo.

[Coley'sdad#8]

Outerwears material with female velcro sewed to it and the male cro adhesived to case.
And YES I sewed it so home ec class did pay off in junior high, it was not just for meeting girls

[WISH1965]

Atta Guy :) I'm still trying to figure out how use my three years of French. Good thing we also play hockey 9 months of the year, unfortunately were not playing in Quebec :(

[edwardsp&b]

I think someone hit the nail on the head saying you needed to go to an overrange clutch system. Once you start hitting the higher rpm's on the 70, that clutch system wont hold up.
Not trying to brag but I have a very fast national 70cvt, I never have the problems you guys are talking about. Im running the overrange kit and hitting way over 1600 rpm's. I havent changed rollers yet this year, and thats been 9 nationals and practice. But I also have to buy springs by the case full.

Once you get your setup on the cvt's right, and you get knowledgeable enough to maintain it, these things arent that tough. I wish I would have asked more questions when I first started tooling on these quads, it cost me a bunch of money learning. Ben not only trashed a tranny one time, he also busted both cases. That little tabletop landing cost me a fortune!

Just know that whatever happens to your quad, someone on this site has had it happen before, and can guide you through the best repair procedure.
Good Luck
bryan

[travis rimmer]

mines the same way once u get it dialed leave it alone and yes brains 70 is very fast more like screaming fast and the pilot

[mydirtkids]

Originally posted by WISH1965
Atta Guy :) I'm still trying to figure out how use my three years of French :(

LOL...These things will sure give you plenty practice with your French:D :D

I drilled the side of the cover just around the webbing for the CVT bearing. I could post a pic later if you need. G-forcepowersports has a pic of the outerwear. After atleast 5 full motos/practices and a couple extra practices we were still in good shape. I did go to the Malossi Over Range kit, but that will set you back a little over $400, and you need to make sure you get the correct package. Plus I THINK (sure someone will correct me if wrong) but the 70 cases need a little machining to get proper clearance (something you could probably do with a dremel, or similar device.

[zach R 7x]

Originally posted by mydirtkids
Yamaha 125 should be on my dealers floor this week... That is going to be a tough one to race though. Kinda a weird class, not many pitsters or 125's running right now. Speaking of running, I have watched a pitster for a while, and they really seem to have more issues than the CVT's... Just not sure how the Yamaha would do. JMO not wanting to pick a fight...

The CVT is out, poked and prodded. I think the setup is good to teach the kids how to handle a track and the other riders. The CVT lets the kids just ride without confusing them with gears...

As far as the Pister goes, you need to check out what Tom at Four Play has been doing with the ones he has.

He has really done some great stuff with the suspension and frame gusseting . They have swapped out the stock motor and put in a dirt bike motor. Could be the future????

[mydirtkids]

Tom has done an amazing job and built a pretty sweet bike! For me, the shifter can wait till my kids are 12. By then, it is 250 time!! JMO

[zach R 7x]

Originally posted by edwardsp&b
I think someone hit the nail on the head saying you needed to go to an overrange clutch system. Once you start hitting the higher rpm's on the 70, that clutch system wont hold up.
Not trying to brag but I have a very fast national 70cvt, I never have the problems you guys are talking about. Im running the overrange kit and hitting way over 1600 rpm's. I havent changed rollers yet this year, and thats been 9 nationals and practice. But I also have to buy springs by the case full.

Once you get your setup on the cvt's right, and you get knowledgeable enough to maintain it, these things arent that tough. I wish I would have asked more questions when I first started tooling on these quads, it cost me a bunch of money learning. Ben not only trashed a tranny one time, he also busted both cases. That little tabletop landing cost me a fortune!

Just know that whatever happens to your quad, someone on this site has had it happen before, and can guide you through the best repair procedure.
Good Luck
bryan

Totally agree with you on this Brian, we went through this same problem last year before we bought the overrange kit.
We run the koso 1000 spring and have had great luck with it ,they seem to last alot longer than the mallossi red springs . I have run the same rollers all year long also.

Tim

[bulldogfallon]

There are a lot of posts here, so I am not sure if you ever mentioned the pipe or rpms you are running at.

I think you may find that some of the faster guys don't run the OR kit, but for the avg guy it definately makes life easier.

BUT I am not sure you are turning enough RPMs to use an OR kit effectively.

Flat spotting can be from heat or even the variator sliders getting caught up.

I would definately look at ventialating the CVT cover (90cc cover with outerwear and holes drilled in cvt cover...no yellow filter in the front).

You should also list the brand of torque spring too since a Malossi 2000 and ZTR 2000 are not even close to the the same., even though they carry the same RPM rating.

using too strong of a spring can result in excess heat and loss of efficiency of power from the engine.

We also mod the rear pulley to help it open and close easier (less drag and resistance to allow it to downshift easier)

If you fill in the gaps from the questions I have from above then you may get a more accurate list of solutions. (Excuse me if they were listed somewhere in the long list of responses)

[EthansDad]

I also found out a neat trick to do with those yamasidas this year. They do get a groove in the top of the ramp that goes left to right, is that what you are talking about? generally shows up in all ramps, but some more than others. That groove causes excessive wear, flat spots and lost races.

After buying a bunch of $70+ variators that all did the same thing, I found out what was the root cause. the back plate (one closest to the motor, on the inside) hits the inside of the variator ramp plate just ever so slightly. that is what is making those marks. my fix, take that back plate to the grinding wheel and tapper off the edge that makes contact with the variator. did that on mine, no more grooves.

The heat issues others discussed will add a multiplier effect to the problem. that is worth checking too.

-EA

[JIM GRACE]

Originally posted by EthansDad
After buying a bunch of $70+ variators that all did the same thing, I found out what was the root cause. the back plate (one closest to the motor, on the inside) hits the inside of the variator ramp plate just ever so slightly. that is what is making those marks. my fix, take that back plate to the grinding wheel and tapper off the edge that makes contact with the variator. did that on mine, no more grooves.

The heat issues others discussed will add a multiplier effect to the problem. that is worth
checking too.

-EA
3 races on our variator same exact thing, Time to grind.