I just bought a used 2003 AC 400 4x4. I have never been a fan of the CVT tranny, some I've disliked more than others. This AC has one of the worst to me as far as having to turn such high RPM's to increase speed. I have read where people put clutch kits and springs in these CVT's but haven't read as to why. Is there a simple solution to make this CVT increase speed at a lower RPM?

This thing sounds like it's running near red line just going 10mph. I can whind it up past 30mph then back off the throttle and it'll sound as if it's turning slightly less RPM than at 5 or 10mph. I'd sure like to find an inexpensive solution to make it turn less RPM's to increase or maintain it's speed.

 

First thing I would try is a belt change and clutch cleaning. A small thing like that can change its behavior.
For all you know its still running the original 10 year old belt.

 

I'm certain it probably has the original belt on it. I could see that a sticky clutch could make a difference in RPM vs Speed but not sure how the belt would make a difference unless it was slipping which I'm not suspecting any slippage from it.

I'll open it up and check things out in there though. It may loosen up with a cleaning and some use but right now it sure has to whind up to increase it's speed. I've owned two Polaris and now have a Grizzly 700 and these three quads didn't whind as much but I had a 400 Kodiak that wound about like this AC does to pick up speed.

I know these CVT's are suppose to be tuned to keep the bike in it's optimal power band at any speed but 97% of my riding I don't have the need for full power, just cruising or putting around so thats why I like manual but now a day manuals are certainly getting hard to find anymore so it's time for me to learn these CVT's I suppose LOL.

 

Clean it with brake cleaner spray, that stuff leaves no residue. I changed my belt once and the old one still looked fine to me but the ATV when from a 52mph top end to 57 mph.
Beats me, why.

 

Thanks for the tip there, strange how the belt made a difference like that, maybe the stretch on it differs with aging of the material?

Are there any piviot points inside that may need a shot of WD-40 or is that too much risk of getting on the pullies and belt? I've only been into a CVT once just looking at it, never worked on them. I was reading some about the weights that are used to determine the speed at which the system changes gearing or starts closing the front pully so didn't know if these weights were on an arm with a pivot point that may could use a shot of lube since it's been sitting and not been rode much.

 

lube with wd but stay away from the sheaves contact faces.
The brake cleaner can only clean the sheaves.

 

Most of the time if you have a factory service manual they will give you a width on the belt that is within spec. If the belt gets worn enough it will be narrower. A narrower belt runs lower in the primary sheaves and higher in the secondary sheaves, effectively creating a lower gear ratio. You should call your dealer and get the specs on belt wear before pulling it apart so that you can measure it.

Your Arctic Cat should have a Suzuki engine i believe, as well as the Suzuki CVT setup. As far as i know this setup uses a wet clutch like the yamaha's. This is a little better setup for keeping the RPM lower. If the wet clutch is slipping it can cause higher RPM, but if the right oil is used, and it is changed correctly, the wet clutch should last a really long time.

If everything is functioning properly and within spec, you can put heavier weights in the clutch which will cause the CVT to "upgear" faster. The heavier the weights, the faster it up gears, which keeps it at lower RPM. Its not too expensive to experiment with the weights, so you could always put some heavier ones in it and if you dont like it, swap em back out. Regardless, heavier weights may reduce WOT performance a little by keeping the engine lower in the RPM's, but it will definately keep your accelerating and cruising RPM's lower.

Hope this helps!

 

Thanks for the info, I was just reading up on the rollers that are in the variator part of the system and how their weight can change the "shift speed" or RPM's the engine is held at. I wouldn't mind sacrificing some top end to lower the RPM's a bit, just revs too much in my opinion. I sure can't idle through the neighboro hood to get to my paths with out everyone knowing I'm coming through, sounds like I'm hauling butt at only 10mph LOL.

As one of you mentioned though, probably best to check the width spec on the belt first, I didn't really think about the width making a difference but I see how it can.

Thanks guys.