Sportsman 500 Questions???

[pvoncannon]

Hey guys new member here.. I have a 2007 Sportsman 500EFI. I have a few questions about it. I am having a problem, when I punch the throttle fully open after a few seconds the motor seems to skip or jump. This only happens when I punch the throttle all the way open. Is this some kind of a rev limiter/speed limiter or some other type of problem? It doesnt happen if i slowly accelerate to high speeds only when I punch the throttle and hold it... Okay, question number 2: My ATV has a rattle around the intake tube under the seat. It is very aggravating, I can tell it is caused by the intake tube vibrating against another piece of plastic. Nothing appears broken or out of place, I tried to fix it my self by placing a piece of foam between the two pieces, it has helped some but I still can hear it. Any help with these problems would be greatly appreciated.

[pvoncannon]

wow great forum

[blueline15]

It's a good thing you're not paying us to answer questions, otherwise I would agree, this service sucks.

To get back on track, for Q1: I would start by checking your belt and clutch sheeves. Belts with start to glaze over on the sides with use (heat and friction). Your belt may have started to do that, and it's slipping on the clutch sheeves under a full throttle acc, but it's not bad enough yet it slips under normal load. Look for the sides to be shiny or very smooth. Compare it to a new belt, and you'll notice there is a bit of texture to a new belt. That's where I would start.

Q2: I would check very closely for any bent brackets, missing bolts, etc. it's not a common complaint. Any way you can post a pic to get a better idea?

[pvoncannon]

Thanks man, I will check the belt and see what kind of shape its in. I really didn't think about that. I will also check around the intake for something to be bent or broken, I've looked before and didn't notice anything but I will check again. It's not really a serious issue as much as it's just annoying to listen to. Also if it is the belt, I have a spare but I have never changed the one before. Is it difficult, or is there anything I should know before I do it? Okay, last question I promise, lol... I have now noticed that when I accelerate to high RPM that my battery light flashes and the tach flashes also.. As soon as I return to a lower RPM or idle this stops. Any ideas? I'm thinking over voltage. Thank You again for any thoughts you may have. I will alson try to post a pic.

[blueline15]

Questions are fine. Just no promises we get to them right away...lol.

The intake noise is hard to diagnose, only cause I'm not aware of a common problem. And without seeing or hearing it...it could be a number of things. Which piece of plastic is it vibrating against?

Not really difficult to change the belt, but it may be the first time you do it. It's usually easiest to get the belt started over the lip of the secondary, and then start rotating the primary around so the belt slowly starts working itself off of the secondary. Installing is the opposite.

Just like this. The belt is off in the first 50 seconds of the video.

Changeing belt POLARIS ATV - YouTube

Changeing belt POLARIS ATV - YouTube

Finally, you're probably right with the high voltage. That could be due to a bad regulator/rectifier, which is also a wear item, only because it takes the spikes in voltage from the stator and turns the extra juice into heat, and electronics do not like heat, so the R/R does eventually die.

Throw a simple volt meter on it, and rev it up and see what the voltage is peaking out at. But that's probably what is going on there.

How many hours/miles on this machine? And any idea how many miles/hours on the belt?

Do you ever idle in gear for periods of time? Another belt tip, is try not to idle in gear for longer then 30 second periods. The primary still spins agains the stopped belt, and that friction will actually "hourglass" the belt in that spot. Putting it in neutral, allows the belt to spin with the primary, avoiding that wear and tear.

[pvoncannon]

Well I have no idea how may hours are on the belt. The guy I bought the ATV from had just bought an extra belt and was carrying it around in the front compartment on the 4 wheeler so that may be an indication that he knew it was going to need changing. Luckily he let me keep the new belt... The ATV has about 140 hours and 900 miles. Seems to have be taken care of. He changed all of the fluids before he put it up for sale. As far as what the intake is vibrating against I am too ignorant to know what its called but it's another black piece of plastic tubing beside the intake or so I think. When I push on the intake it will stop making that noise when I rev up. I can't find anything broken or bent. If I get the chance I will take some pics. I have only had it for about 3 weeks so I haven't really let it idle in gear but thanks for telling me not to do that, I didnt know. What voltage should I look for during idle, and when I rev it up? I'm thinking its the regulator also... Does it hurt anything to run the machine with if the regulator is going bad?