Polaris ATV Forum banner

1 - 20 of 27 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter #1
Well I couldn't find my problem by searching so here it goes.

A few days ago our 2000 Sportsman 500 started cutting out at about half throttle. Throughout the entire rpm range a hollow sound is made. It sounds like when I start my Honda without the air filter on. It has a near identical sound. It just feels like it doesn't have the power at the upper rpm levels.

I've replaced the spark plug, air filter, and dumped a pint of seafoam in a full tank. Ran it and it helped some but the problem is still there. Any ideas?
 

·
Registered
Joined
·
3,417 Posts
A few things to check:
ETC(electronic throttle control)
Air box
Throttle cable
Clogged exhaust system
Incorrect timing
Diaphram in the top of the carb.
Water or trash in fuel
Rev limiter
 

·
Registered
Joined
·
745 Posts
Probably a cracked carb boot messing up your fuel mixture.

Also, that's too much seafoam. If I remember correctly, it should only be about one ounce per gallon, so only 3-4 ounces are needed.
 

·
Registered
Joined
·
147 Posts
Nope, its doing the same thing mine done. Ill bet the exhaust lobe on your cam shaft is worn out. Pull the front plastic the gas tank and take off the valve cover. I'll bet you the cams worn out. Took me about 10 to 15 mins to get the front plastic and the gas tank out.
 

·
Registered
Joined
·
3 Posts
Discussion Starter #6
Talked to the polaris dealer a few days ago and he's pretty sure it's a cam going out. He guessed it would be around $800 parts and labor. Talked to a dealer in missouri and it's about $250 cheaper through them so it's going to them soon.
 

·
Registered
Joined
·
479 Posts
Not trying to steal your thread. I just bought a used 500 1998 model with no history.After cleaning carb and new plug it starts and idles fine. On the road when you hit 15 mph it just looses power. It doesn't slow down but just acts like it is in too high of gear. Is this a cam problem? At lower speeds it seams to run fine. I also own a 98 500 scrambler and it does not no this. Can Install a HO cam? What else is needed. I am a auto Mechanic and not afraid to do this my self. What about this cam? Aaen Performance - Polaris ATV Four Stroke - ATV Accessories on top right.
 

·
Registered
Joined
·
16 Posts
If you get a good price on a cam kit let me know, I've got a 98, 500 with no exhaust lobe on the cam, does the same thing yours does. Does yous idle OK, mine will, but has no power as you accelerate. thanks Jack
 

·
Registered
Joined
·
16 Posts
Sportsman 300 bogging out

I am having a similiar problem, i have a 2008 sportsman 300 and it recently was "bogging" out when i went more than 1/4 throttle. i fixed it but now when it needs power(mud,hill, etc) and i puch the throttle more it does the same thing and idk what's wrong..
 

·
Registered
Joined
·
5 Posts
my 2009 is doing the same thing as your 2008 and it only has 312 miles on it. Tried sea foam. Runs good till you hit 12 mile a hour and cuts out.
 

·
Registered
Joined
·
1 Posts
Hello
I am having the same issue with 1996 500 Sportsman, did you get the problem figured out? I have checked the carb, boot, intake and exhaust and have not found the problem yet. Thank you
 

·
Registered
Joined
·
99 Posts
Wow, I never heard of cam issues with Polaris(Fuji) engines, unless you don't change your oil much. I had a hatchet type rock break an oil line on my 97SP500 in the pouring rain, I thought the motor sounded odd but we hammered on. The next day, my truck had oil in the bed, I checked the mach. and there was only 4oz. of oil left in the 64oz. system, I figured the motor was toast. The cam being furthest away from the oil is what I checked first, it was like new. Did an oil/filter change, had a little metal on the magnet, that happened at 8000mi, I sold the ATV w/15000mi. on and it's still running. If you service the motors on your Polaris you'll find that their the best part of the mach.. The clutches when they start to fail will do some strange things. Also, you MUST adjust the valves if you want your motor to last. The valves get tight because they recede into the head from wear, you lose your clearance and put excessive load on your cam lobes.
 

·
Registered
Joined
·
337 Posts
Muddy: I have a neighbor who had two 500's. They BOTH wiped their cams at about the same mileage. They were Late 80's models, but not the same year.

At what mileage should you have the valves adjusted, and does this apply to 800's??
 

·
Registered
Joined
·
2 Posts
I had the exact problem!... And i got the answer!

you need to have a seal around your airbox....that what i did and i float mine and mud through anything
 

·
Registered
Joined
·
3 Posts
90 polaris boggs when it has a load on it

I have a 2001 polaris sportsman 90 I put a new carburetor on it runs and idles good when you have it up on blocks put it on the ground it will still idle but when you give it gas it bogges under a load and wont move put it back on blocks and give it gas and it runns good Im lost for words
 

·
Registered
Joined
·
20 Posts
I replaced many cams when I was a dealer on the 500 engines. Lobes rounded off. Some had low miles as well. Polaris told us they had an issue with the vendor, but could not tell us which units had the bad cams. Running poor quality oil will also cause issues.
 

·
Registered
Joined
·
3 Posts
I replaced many cams when I was a dealer on the 500 engines. Lobes rounded off. Some had low miles as well. Polaris told us they had an issue with the vendor, but could not tell us which units had the bad cams. Running poor quality oil will also cause issues.
So you think it is a bad cam doing this
 

·
Registered
Joined
·
102 Posts
I just went thru all this, there is a video on youtube of what all these guys are having problems with, I post a few weeks ago and linked it. Anyways I pretty much did a ground up restoration on my 01 500 HO, and guess what, it was the friggin fuel valve. A very small piece of RED plastic and shaving would clog it.

I miked my cams, mint to factory NEW specifications, carb was gone thru 3 times, coil tested, I tried everything I could find here. One thing tho, mine would run perfect with no air filter or air box. But not with the filter on, and it ran perfectly fine for 1/4 mile then act up. Would have to wait till the next day before it would run perfectly for 1/4 mile maybe 1/2 mile then same thing. I checked the fuel pump, lines, pulse lines. So before you spend a bunch of money make sure you trouble shoot exactly first. Cams OEM are 220.00 on ebay or fix my toys, get a manual and it should take about 6-8 hours for a very thorough non mechanic to do it, exactly by the book.
 
1 - 20 of 27 Posts
Top