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Discussion Starter · #1 ·
Thanks in advance for any suggestions.
I have a 99 Sportsman 335. It has run great until recently. I noticed it wouldn't go as fast as it used to. It starts and idles fine. It accelerates up to about 17 mph in High, but seems to max out.

Thinking it was power/engine related, I put in a new spark plug, replaced the spark plug cap. No change. The air filter is not new, but the paper element looks pristine and I cleaned the foam cover. I pulled and inspected the carb. It is clean throughout and no debris in the jets, float bowl, float needle. Fuel pours out the hose to the carb. Being a vacuum driven fuel pump, I haven't figured out how to check it's pressure - if I disconnect the output, the carb gets no fuel - right? I did open up and inspect the fuel pump. All the diaphragms look clean and there was no contamination in any of the check valves. I'll admit, I haven't changed the fuel filter, but it looks clean and I can blow through it with virtually no resistance.

Then I thought maybe the drive belt was the problem. I ran it with the cover off (CAREFULLY!) and the belt only goes about 1/3 of the way out the clutch. New Polaris belt does the same. With the belt off, the clutch closes all the way and the clutch seems smooth when I squeeze it together. There was no dust, rust or debris at all in the clutch mechanism. There was an almost imperceptible amount of belt residue on the clutch plates, but I buffed that off with 600 grit paper. It is baby butt smooth now and same behavior.
Any ideas would be greatly appreciated.
 

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First off welcome to the board!
 

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Try removing the air filter and run it without a filter just long enough to see if it makes any difference. My filter became oil soaked and it did the same thing as yours. New filter and it runs like a scalded dog.
 

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Discussion Starter · #8 ·
f01212 - No, but it is not an over ride issue. In reverse (without the button pushed) it coughs and misses like the limit is supposed to. In forward it runs smooth - It just quits accelerating.
 

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exhaust plugged? i had a motorcyle muffler plugged with acorns. went about 1/3 thottle and wouldn't go any faster
 

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i had the same issue with my 00 335. i had a new belt installed, spark plug, air filter. still did nothing. it seemed to me the engine rpm stop at a certain rpm when in gear. and it rev up high when in neutral. it drove fine. pulled like a tractor with no issues. but top speed was round 25, and 35ish when going down hill. im guessing its either the tranny(clutch), or if there is a rev limiter. but i cant say forshure as i sold it and said screw it. it had 7k miles on it. but it worked great.
 

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Discussion Starter · #12 ·
Thanks all - more problems!!

I don't live on the ranch and travel a lot. Just got back up there. Did a compression check - 45 psi. OK - engine problem.

As I was doing that, I looked down at the clutch cover. Long story short, friends daughters used in to check their horses. Shredded the brand new belt, strings from the belt cut through the clutch cover. Took it all apart, got the new (trashed belt off). Thought I'd spin the clutch to see if it was OK. Started the engine. It sounds like a couple sockets bouncing around inside the crank case.

Anyone have a source for re manufactured motors?
 
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