Hey guys, just picked up a 500 sportsman. But got an odd issue.

Has spark has good compression but still won't fire. And when it did it poped back thru the carb. Reset cam timing, played with mag timing as well.

Any ideas?



Just picked it up the other day, needs a few things to getr back upto shape( gas tank, rear brake rotor, pull start) and I think the starters gettin weak, won't crank passed tdc now that I've redone cam and mag timing( stiff, but can do it by hand tho)

 

Average compression should be between 55-90 psi or so because of the decompression feature of the cam shaft. Check your exhaust cam lobe as they had problems with soft heat treated cams on the 1996-2000 500 engines.Hard starting,popping back through the carb was a couple of the symptoms. Here's one that was ground down on a Scrambler 500. Bad Cam Pic - ATVConnection.com ATV Enthusiast Community Plus if the cam is ok,simple things like a cam detent lever return spring broken or out of place,stator timing off, can make turning the engine over hard on the electric starter.

 

One thing I haven't check is that auto decomp part. Dint even wknow about it.. I'll ckeck that right now.

 

This may help along with cam lobe measurements that's in the manual.

 

Ok so checked the auto Decomp ball is there and counterweight springs back Reset valves to 006. Not much difference..

Looks like I need a new starter, this ones too weak.


Cam lobes look good, minimal wear.

 

Can get them fairly cheap. Plus if mine I'd replace the bendix as it takes a beating also. Couple places you can look at plus plenty more on ebay.DB Electrical - Sportsman
http://www.ebay.com/itm/Starter-Drive-FITS-POLARIS-SPORTSMAN-500-HO-EFI-RSE-96-10-/280638338860?pt=Motors_ATV_Parts_Accessories&hash=item415759372c&vxp=mtr

 

Thats the cool thing, you can aftermarket starters for just about anything online with quality equal to or better than oem for a fraction of the cost. Those oem starters, especially Polaris, are really expensive. Finding a part for $50 instead of $300 will make for a much better day. I'm going to save this db electrical site as I need to get a starter for my rancher, been content to pull start it as starter went out recently. Its pretty easy to pull start though, guess that's the one time not having big power is an advantage lol.

 

It get worst then that Polaris just has a insane mark up even on parts they do not make.

Example : I needed a new fan and my dealer wanted $300 for a new one. The OEM fan is made by SPAL of Italy and mine was the model VA09-AP12/C-54A FAN (11") Polaris Part #2410288 .

I found a new fan on Ebay for $85 shipped , when I received the Fan sure enough it was a SPAL model VA09-AP12/C-54A Spal's part# 30100411 .

Not a aftermarket fan, but the exact same fan as the original . Talk about a mark up.

 

NOT the dealers fault in most cases as it is Polaris industries itself! We had insane dealer prices we had to pay Polaris just to stock common items such as oil,filters,etc. Hard parts costs were even worse. Add dealer markup to the already insane prices and there you are. No different than Honda,Yamaha,Kawasaki and so on on parts and accessories.More money in parts and service to be made than from profit on the machines themselves. About the same as the auto dealerships. A little checking around and you can find good deals on aftermarket or oem parts at a lot better price for the pocket book. For some people that I knew couldn't afford oem parts,I was able to steer them to different places even while I was still at the shop. I just made sure I was outside and no one else around to hear..

 

Ok had starter rebuilt, now that it cranks it pops back thru the carb. Tells me timing it off, but don't know where.

Reset cam timing the other day( prev owner had it a bit off) rest valves to 006. I did notice the flywheel had a bit of play back and forth on the keyway( key isn't broken) but once it's tight play is gone.

Any ideas where to look next?