OK so I have a 97 Polaris 400 xplorer 2 stroke, I got it for free and was not running when I got it. Moisture got into the cylinder from sitting outside and it was locked up so I broke it free with a crowbar through the clutch. Filled the top and with oil and let it sit overnight and then it would turn over. Cleaned the carb, got it running and noticed it was blowing white smoke, replaced the head gasket exhaust gasket and intake gasket. I did notice some minor scoring on the piston through the exhaust port. Now I have it all back together and it still blows white smoke, tested the compression and it is a little over 120 PSI which is good I hear. Spark plug comes up and appears to have either coolant or gas on it. It does not start easy it takes a full choke and tapping the throttle.I am not a ATV mechanic by no means but have worked for 12 years as a collision repair technician. So I do understand how to take things apart and disassemble them and general mechanical skills. I'm having an issue with problem-solving on this one though and would appreciate any help that is out there, thank you very much.

Josh

 

If you're going to work on these older ones you have to do it right. Have the next over size Wiseco piston that will clean up the bore and and all new gaskets.May as well rebuild the water pump seals(2),bearing and gasket. Hard to piece meal a 400 and make it run right,toomany parts involved.Plus with scratches in the cylinder,this is a sign to have it bored. 120psi is on the lower end. A new top end should be around 135-140 psi or so if done right.

 

Thanks for the response, judging by your name I'm taking it you know A thing or two about these old Polaris's ha. All I need this thing for is to take me on and off the ice for Icefishing . With your experience are these quads pieces of ****? The last thing I want to do is get into A constant money pit. I enjoy doing this kind of work but I don't enjoy doing it when it takes my time away from fishing ha ha. I'm just debating whether or not it is worth getting into or not. I appreciate your input.

 

This engine has more parts than most 4 strokes. They can be money pits if you just repair/replace here and there as problems will always crop up. Only way to make a 400 reliable is to start from the bottom end and rebuild it with a fresh top end also.Then it will probably last for years,but it takes time and a little $ to do so.

 

How difficult are we talking on the bottom end ? I am a novice skill set when it comes to internals. The top end I believe is easier to me. Just trying to get a feel of what I'm getting into. This is a 2 stroke model, I'm not sure the diagram you sent me was for a 2 stroke? Thanks for the parts list I appreciate it. Looks like you must still have access to some good stuff.

 

Diagram I sent was on a 400 2 stroke bottom end. It doesn't show the counter balancer and water pump and crank shaft. Just shows the main bottom end bearings and gaskets.If you really want something that can help on rebuilding or help you decide to walk away,the manual is the best source.Really goes into detail.Here's a free link to a 96-98 service manual.https://www.google.com/url?sa=t&rct=...Z7Rqhg&cad=rja

 

I really appreciate you taking the time to send me those, it appears to beat the hell out of my Haynes book I picked up. I'm still not certain I want to get that deep into it. What are the odds of just putting a top end on it? It has 2900 miles on it. Im just trying to see if the odds are against me. You have worked on these before I'm guessing? Do the bottom ends not hold up very well after 2900 miles?

 

50/50 Since it was picked up not running. You could do a top end but if the lower rod bearing or crank bearings are worn(you can kinda of check this out) they can take out that new top end.

 

That manual that you sent me is the cats meow. I'm going to do some studying and print a zillion pages out and see what I'm getting into. You were completely right when you said it was very thorough. No wonder it's so easy for you mechanics! Jk. I'll let you know what I decide. Thanks

 

This is a copy of the shop manual like I had at work.Not like the Clymer or Haynes manuals that copy bits and pieces from the factory manual and can leave you more confused.