CVT running hot and burning belts

[mbBoy]

I bought a used 2016 Arctic Cat 500, same engine and CVT as the Kymco MXU 450i I believe, and have been having problems with the CVT running hot and burning the belts.  The ATV only had 514 miles on it when I bought it and it ran very nice.  My wife has been driving it since, no craziness, very little mud, mostly club rides and rides with me around the area, but she did complain about it being very warm around the CVT cover.  I didn't pay much attention to it until one day, after riding for awhile in the summer heat, it just revved up and came to a stop.  We towed it back home and I pulled the CVT cover off to find the belt literally disintegrated.  I replaced the belt, but being a newbie, didn't think to clean out the ventilation ducts, put it all back together, fired it up and it ran like a charm.  The next weekend we went out again in the summer heat and it wasn't very long until the same thing happened.  Towed it back and pulled it apart and this time it got so hot it melted the rollers and slide guides in the primary clutch and the rollers in the secondary.  Bought all new rollers and guides, cleaned out the vent ducts and put it back together.  By this time it had 747 miles on it.  Since that time we have been running it on short rides, monitoring the CVT cover temperature with an infra red temp sensor and it still runs very hot, over 200 degrees in less than 10 miles.  I have tried exchanging secondary clutches with my 2013 Arctic Cat 500, which has the same power train, and that didn't make any difference; the 2016 still ran hot and the 2013, running beside it ran much cooler.  I have't exchanged the primary clutches yet, because I couldn't get the nut off, but thought some of you may have some ideas on what is causing the heat.  I did pull the wet clutch apart, and it looks like new.  If anyone has Kymco service information on the CVT, I could use it.

[Hndyman55]

Does it idle for long periods? Very little airflow through the belt box at idle. When riding slower trails do you keep it in low?  Running slow in high can cause heat to build up and burn through belts.  Have you tried posting on arctichat?


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[mbBoy]

Hi and thanks for the reply.  No, we don't idle for long.  Most rides we go on are usually on trails at 25 to 35 mph.  When we do ride slower than 15 to 20 mph we shift to low.  es, I posted on ArcticChat and got some good info and tips, but no solution, yet.  I spoke with Arctic Cat in Thief River Falls as well as he suggested that the secondary clutch needed replacing, but I am hesitant to spend the money on a new secondary when trying my 2013 secondary showed no difference.

[CROSSBOLT]

CVT's run very hot normally. "They" even sell non-contact cvt belt temperature guages specifically for ATV and sxs vehicles. Heat build-up negligble at idle but ramps quickly under load, sorta like a diesel engine. That is one of the reasons there is generally an insulated plastic cover on the scooter cvt so we won't burn our pretty legs!

[Hndyman55]

Just thinking here... you say it gets really hot and the belt tears up. So I’m guessing the belt is slipping. Is there a glaze on the pulleys from the previous belts. When you replaced the rollers in the secondary did you disassemble and clean clean everything so no belt debris lodged in it?  Is the belt box totally dry( no oily residue)?  Have you thought about clocking the secondary to the next position to give it a bit more squeeze( less slippage).


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[Hndyman55]

Now I realized you said you swapped the secondary’s so that might be fine. It’s gotta have something to do with the primary or behind it. Did you install the belt with the arrow facing foreword? Any damage in the primary ramps where the rollers reside or the fixed plate ramps? Maybe there is an issue with the bushing in the center of the primary that rides on the shaft? Loose or wollard out. What are the rpms compared to the other machine at the same speed?


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[mbBoy]

Now I realized you said you swapped the secondary’s so that might be fine. It’s gotta have something to do with the primary or behind it. Did you install the belt with the arrow facing foreword? Any damage in the primary ramps where the rollers reside or the fixed plate ramps? Maybe there is an issue with the bushing in the center of the primary that rides on the shaft? Loose or wollard out. What are the rpms compared to the other machine at the same speed?
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Yes, I installed the belt with the arrow forward.  No, no damage to the primary ramps; they appear to be in pretty good shape after I cleaned all the melted plastic from the melted rollers.  I changed the bearing in the CVT cover, thinking it was possibly the source of the heat, but that made no difference to the CVT temperature.  The rpms are a bit higher than the 2013 machine, probably 5 to 7%.

[mbBoy]

Just thinking here... you say it gets really hot and the belt tears up. So I’m guessing the belt is slipping. Is there a glaze on the pulleys from the previous belts. When you replaced the rollers in the secondary did you disassemble and clean clean everything so no belt debris lodged in it?  Is the belt box totally dry( no oily residue)?  Have you thought about clocking the secondary to the next position to give it a bit more squeeze( less slippage).

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I don't think the pulley faces are glazed; I did clean with scotch brite pads when I had them apart. And yes, I cleaned and blew everything out.  Inside the CVT housing is dry, just a bit of blackish residue from the burnt belts, but I cleaned it out with varsol before putting it back together.  i did try reclocking the secondary to the next clockwise hole, but it didn't seem to make much difference.  I think I may take it one more hole over the holidays and see what happens.  I was hoping someone might come up with a service manual.  By the way, where does one find one of those heat gages you spoke about?

[Hndyman55]

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[mbBoy]

cool! Thanks

[airshot]

Service manuals are cheap when compared to the cost of parts chasing. If your gonna keep it get a factory service manual. I have an online manual thru "Cyclepedia"  and they even offer a trouble shooting service. Mine was 50 bucks for a lifetime , also bought a hard copy for another 50.  Cheap insurance when I have a question