Figured I'd find something searching the forums, but didn't get to an answer that way.

I recently acquired a two-fer pair of 2002 325 Magnum 4x4's from the original owner. obviously very little use, (so little that the rear brake foot pedals still works).

One runs perfectly.

The other turns over just fine but won't fire even on starting fluid. It has strong spark but compression is only 30psi. Seems to be pushing air back thru the carb.

Before I go randomly tearing into the thing, I'm thinking there must be a "thing" these 325's do to themselves. I saw some allusion in another post about crank nut coming loose, but didn't see that all played out.

Plan is to fix this one then head the other off at the pass.

If someone could point me in the right direction, that'd be great!

 

Standard compression is between 70-90 psi. With compression this low don't think the decompression arm on the cam could be causing this. You can pull the cam cover and check,but probably going to have to tear it down. Best to have a manual on this before you start.Here's a cheap one for 5 bucks. 2002 Polaris Magnum 325 Service Manual PDF Download

 

I've got a tech sparks manual for my '03 trail boss 330. Are they alike enough or is the 330 that much different?

 

Pretty much the same engines. No sense in getting another manual as far as tear down goes if needed.

 

Thanks OPT - I'll dig in and past back with the results.

 

Well, finally got around to getting this sorted out. Broken spring for the automatic decompression...if I'm describing that correctly.

Tiny little coil, with the tab broke off.

Runs like a top now.

 

Ran into that several times also. Plus a couple times I didn't hold the spring and the counter weight good enough when I replaced cams and the spring slipped off the stop pin. Would crank up,but wouldn't run right. Glad you found the problem.