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03 Polaris Predator 90 - clutch, rollers, spring? help!

4153 Views 20 Replies 3 Participants Last post by  jmaxwell
First time joining a forum, I usually just read them, but I've hit a wall. To sum it up, I'm a momma to a rough riding 7 year old boy. I do all of his quad and dirtbike maintenance. Might take me longer than a shop, but I figure it out and get it done. Anyways, The other day he was riding hard and he hit a big size hole. The quad stopped moving forward as he was pushing throttle. The quad didn't die, it just wouldn't move. He turned it off, back on, and pushed throttle, and it moved. He came up to the house (he knows momma's rule - when you hear or feel something off, bring the quad to me asap) He told me what happened and I thought throttle cable at first. Checked it and chain, they were both fine. I had him do a test ride in front of me, and he goes about 20 seconds up the driveway and then it stopped responding to the throttle again (example of issue is almost like when driving a manual car and you pop it into neutral while rolling and revv it up) I'm on day 3 of tearing into this quad and still unsure. I have CVT cover off, and access to the clutches and belt. The belt is tight, (as I assume it should be) I hit the start button and can hear a little bit of clinging but, it starts (i'm thinking the little slider pins may have broke off, but I don't think that has anything to do with movement of the quad. Just another issue I'll get too once I know the dang thing will move) The clutch near the rear (I think this is called the secondary) I can turn with a little bit of force and see that it moves the chain. I have read about rollers, and a torque spring. I found rollers on the diagram, but nothing is labeled torque spring. I see 1) seat spring, 2) spring compression and 3) spring weight clutch\. All 3 are located in the secondary clutch. If someone can please tell me what spring I need to replace, I would appreciate it. Also, as for rollers.. wow what a mess! I have yet to get confirmation of stock 90cc roller weight. I read somewhere they are 3grams each. But like I said, I read that only once. The diagram shows 6 rollers, total. There is nothing added to the quad. Everything is bone stock. I read a forum that said 90cc's should have 30-48 grams of total roller weight. Well, that's 5grams - 8grams per roller. That seems like a big difference. And if 3grams really is stock weight, why is someone recommending 5grams - 8grams?

I got off track a little bit - are the recommendations to change rollers and whatever torque spring going to fix the issue? If anyone has alternative ideas or some sort of testing that I can do, please let me know.
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The Chinese quads have a variator that drives the clutch, so the belt is tight at idle, the clutch weights simply do not contact the bell at idle. The stock weight of the roller is not specified in the service or parts breakdown.

I suggest the belt or clutch got wet and slipped till it dried off - as long as the belt moves outward on the variator and is drawn into the clutch sheaves speeding up the clutch, the shoes will move outward and lock up against the bell which turns the transmission shaft.

Heavier weights will cause the variator to move to full engagement faster and may cause creeping at idle - unless a spring is broken, there is not much need to replace one.

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Well, I'm confused as to whether it is revving and not moving or not revving as the throttle is opened
Upload a vid to VIMEO and post the link here
Unfortunately the Polaris 90 is an entry level ATV and is not intended to be ridden 'hard' - I don't know what could be damaged in the clutch other than dislodged rollers in the variator or worn out shoes in the driven clutch. It's perhaps more likely something loosened or broke when he hit the hole.
It quite awhile to get the video to play, but the RPM's never comes up enough to get the variator to close - there is something wrong with the throttle or the ignition.
From the way it was running, I would say it might be running with the choke on, have water in the carburetor or is prematurely hitting the speed limiter
Actually, the curved piece of metal is for the throttle cable - the choke just goes straight in

The way it acts when you open the throttle it goes from firing on every stroke to firing every other stroke - it what's referred to in the industry as 4 stroking - it might be the carb has water in it or the main jet may have fallen out - it might be an electrical problem and losing spark above a certain RPM.
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Now you have to consider a loss of spark - connect a timing light (not for checking timing) just to see if it is still sparking as the engine dies - if it's not a loss of spark then it's back to compression, crankcase compression, fuel and air in the right amounts.
That is a vacuum port - Polaris stuck a short hose on it (#4 in the pic) and then plugged the hose with a plastic plug (#3), Suzuki and Kawasaki used a vacuum operated petcock and the fuel was automatically turned on when the engine was started and shut of when the engine stopped. Yamaha just used a vacuum port cap like you can get at any auto supply and some hardware stores. Eton, Dinli and Aeon all had a method of capping the port and one one of them tapped threads in it and put a screw in with an aluminum or copper washer to assure a seal. However you do it, it needs to be plugged.
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