New carburetor has came in, but nothing lines up. Can I get some definite differences in appearance between 400 and 500 motors? My intake doesn't fit the carb, my breather box doesn't fit this carb. I don't mind ordering what I need, I just want to make sure that since I know nothing about this machine, that someone didn't just swap a 500 motor onto this 400 frame. I don't see cc's stamped anywhere on it. Any definite give aways between a 400 and 500 motor?

 

If you have a 400 2 stroke the head looks like this.


500 engine looks like this..

 

Is that roughly the only change? I'll check tonight when I get home. I appreciate all of your help thus far old Polaris tech. I'll keep you updated.

 

It's like comparing apples to oranges,completely different engines.

 

Is the spark plug easily accessible on the 400 - as in you can easily take it out? My spark plug is deep in the head and has a big red rubber spark plug boot over it. It looks nothing like this one on eBay:
00 Polaris Scrambler 400 4x4 Engine Motor Nice | eBay

 

Now I'm convinced that my Polaris 400 has a 500 engine on it..... This is what my engine looks like:


This is what I should have :/

 

Yep,if the title or vin# shows a 400,then someone has swapped engines..

 

Yep title and vin match up and show 400 Scrambler... Now I'm back to trying to figure out why I can't get past an idle on the 500 with the 500 carb setup. Everything should match up now, and looks like I'll have a 400 carb for sale :/

 

Since we've verified what engine you do have now,pull the valve cover and inspect the cam lobes. "If" this is a 1996-2000 500 engine,it's subject to exhaust lobe failures as a lot of them were.If you've eliminated the carb,this is the first thing I'd check along with valve clearance if the lobe is okay. .006 intake and exhaust clearance.Symptoms of ground down lobe was that the machines would idle,but not take throttle and if the cam lobe was really ground down,backfiring through the carb also.Here's one member that had to change his in a 500 Scrambler.http://forums.atvconnection.com/pola...d-cam-pic.html

 

Holy Smokes, I'll tear that down tonight... thanks again for all of your help!