Hey guys I've been looking around at several different forums and it seems like this place has more people who know what's going on than anywhere else I've found. Before I blow too much smoke and somebody calls me out, here's my dilemma: this weekend I was riding my 1995 Xplorer 400 and blew a hole through the top of the engine. I haven't had a chance to take it apart to see exactly what happened and I don't know a whole lot about the 2 strokes. The hole is near the back of the engine (transmission side) and I'm assuming a rod broke loose and punched about a 1" diameter hole through the top of the block. I've done quite a bit of research and have been trying to find a replacement engine without much luck. I have read that the xplorer and scrambler used the same engine but my biggest question is are there any other atvs that used this same 378cc 2 stroke engine? Seems like if I broaden my search maybe I can come up with something less than the $1,100 fully rebuilt engine that I found. Any help or advice would be greatly appreciated.

 

Polaris started using the 400 two stroke in 1994 and put it in the Explorer in 1995..They also used it in the Sportsman until around 97-98.(two stroke Sportsman with straight axle).It was also used in the Xpress model a couple years.Hope this helps your search..

 

Thanks a lot! I was thinking they would probably be the same engine but couldn't find anywhere to confirm it.

 

If you remove your carb and intake boot and reed cage assy I bet you will find a broken piston skirt. As it breaks, the pieces fall down around the crank and due to not enough clearance, it bust a hole in the bottom end of the motor. It's a polaris piston problem. They aren't strong enough and will break.

ftwflh has a motor for sale. Check this out.

http://forums.atvconnection.com/pola...gine-sale.html

 

I did read about the piston skirt problem when I did a search on this forum earlier. I'm planning on tearing it apart tonight to see what actually happened. I'm sure I'll let everybody know when I get it apart.

I saw his motor and that was one of the main reasons I posted the questions. Thanks for your input!

 

Well I started on the teardown tonight. Got most of the stuff out of the way so I could see how bad the hole was. Ended up taking the head and reeds off to take a look at the rod and piston. Judging by what I can see it looks like a piece of the piston broke off and got slung by the crank. Everything still turns smooth and other than the piston and casing looks good. Still have a ways to go before I get the engine out so I can tear it apart and see just how much damage it did. Had no idea how hard it was going to be to get the engine out of one of these.

Here are some pictures so far. Sorry for the bad quality. Cell phone was all I had. Input is appreciated

 

I still have the engine.$600+shipping.It is all stock.
Drop a pm if interested