I have a 2005 Eton Viper 90, and I'm having issues.. First it starts and idles perfectly. When you go to take off it kind of shudders then takes off but not like it should. If I get on even a slight incline it won't pull up it. It acts like there is something holding it back and it does not rev up either. When it does go it's not smooth, it's acting like it's missing. However once it gets going fast enough it runs perfectly. Even with my son on it, he can't go up the hills he usually can.

I've pretty much narrowed it down to something not working right in the CVT. I've taken it apart and cleaned it but the problem persists. I can't find anything online that tells me how to trouble shoot the CVT system. I've seen quite a few suggestions to replace the rollers and belt and see if that helps. The belt looks good and the rollers appear ok also. Pretty much out of ideas.

I've already gone through all the normal trouble shooting, plugged spark arrestor, low compression, carb issues etc. all that checks out good.

Thanks

 

If the rollers and sliding clips are in good shape,belt in decent shape then probably the centrifugal rear inner clutch. The friction surface on the shoes get worn and slip,can't grab and transmit power to the gear case. Item #7-2 in the parts break down.I'd still replace the belt also if in doubt. CVT Driven Pulley : Get 2 It Sales, LLC, ATV, Dirt Bike, Go Kart, Moped, Scooter Parts!

 

Thanks old polaris tech. I checked that when I had it apart and they appear to be glazed over. They look like little brake pads, they look like they have clear lacquer over them. Totally glazed over. Is this normal or should they be like brake pads? Also the piece that goes over them that they grab looks like it got pretty hot at one time (big bluish black spot)

Thanks

 

Polaris uses similar type clutches and the ones I've replaced weren't lacquered over. They looked like this aftermarket one,plus blue on the drum is usually a good sign of heat and it possibly has been slipping.New Clutch Carrier Assy CVT Polaris 90 Predator 90 Scrambler 90 Sportsman 90 | eBay

 

I didn't think that was normal! I'm almost sure that's the issue. I'm going to go ahead and get the clutch, rollers and belt, why not do it all while I'm in there. About $70 for everything.

Thanks for your help! Always greatly appreciated!

 

Before you go ordering parts try a simple solution first.. Blow everything out and use a fine sanding pad to clean up the surfaces. When sanding the surface sand strait up and down not in circles.

 

I knocked the glaze off the pads but it didn't make a difference.

Every once in a while I get a good squeal from the CVT area like it's grabbing.

I put rear end up on blocks and it seems to rev up and spin the tires good.

This is turning out to be a big PITA.

 

In a no load situation most machines like this will attempt to grab and spin the tires. Under a load it's a different story. I gave up years ago trying to deglaze clutch plates on these little automatics and also on friction plates on manual clutches. Just ends up being double work when you have to take em back out and install new ones.

 

I did a little more testing and with the front brakes locked it will move forward with me (215lbs) on it. When you go to take off it moves most of the time then it's flat, it acts like it's starving for fuel, it's real choppy and shudders.

While I had it on blocks I ran it and looked at the CVT, it appears to be working properly, the front sheave pushes out as RPM increases and the rear spreads apart then it everything goes back to normal as the RPMs come down.

If the clutch was really not grabbing it wouldn't take off with the front brakes on right? I guess I'm starting to second guess myself, I know the carb is spotless, the air filter is new, the top end it new. exhuast not plugged, what am I missing??

 

After screwing with this for most of the day I figured it out, I think anyhow!

I was going over everything with a fine tooth comb, I was going to test the coil, when I went to disconnect the two wires one of them was VERY LOOSE, the connector had loosened up enough to where it was just hanging on. (No tension when I pulled it loose) I crimped it down, shoved it on and took it for a test. Now it runs better than ever! I would expect this with a new top end and air filter.

I'm getting a good amount of squealing out of the CVT now, probably from it being spotless, I'm going to throw a belt on and see if that helps.

Thanks for all the help! It's greatly appreciated!