I have a 2000 Polaris Scrambler 400 4x4. Sometimes I forget that Im not on my DS650 and I jump the Scrambler. Im 6'4 305 so Im sure you can imagine the landing is a tad bit rougher on the quad. I have cracked the transmission housing before and do not want to do it again. I heard about a chain roller that Ritter Cycles sells. Does anybody know anything about it? Does anybody have any other sugestions to help make a Scrambler more jump worthy?

I have a tensioner on my 95 Scrambler (non concentric) that has been on since the second month of ownership. It's the way to go, no chain or trans problems at all. I got mine from HPD but anything is better than nothing.

bigR, I too am in your weight height class and after having to do a complete trans rebuild after only 1 year have questions about how much stress the concentric drive puts on the trans internals as well as the case. From what I have seen I believe that running the chain with the recommended little to no slack causes stress on the output shaft and the case due to not so perfect tolerences. I think that running a tensioner with a bit more slack than recommended would solve some of this stress. Anybody else have any thoughts on my ramblings [img]i/expressions/face-icon-small-wink.gif[/img]?

Running a tensioner will help, BUT you will still break a chain occasionally. HPD and Hotseat both have tensioners. Make sure you upgrade your transmission brackets to the newer thicker style bracket if you don't already have them. Also, make yourself a metal guard to replace the cheap plastic stock piece and even if the chain goes, you will still be protected.
Chain Guard

Cracked transmission case.... Don't want to do it again
 

just bumping it up to the top for another forum..... viewing kevins home-made chain gaurd..... [img]i/expressions/face-icon-small-happy.gif[/img]

Cracked transmission case.... Don't want to do it again
 

hummm a chain tensioner will really help,the sprockets will like it too,i run the HPD one and it fit great,pretty easy to install,run very good.

Cracked transmission case.... Don't want to do it again
 

The tensioner sounds like it should help protect the chain from stretching, but what about when it breaks? Mine just broke going about 10-15 MPH and rapping the throttle. The master link broke on the sideplate and bound up in the tranny case, which punched a hole it it. It seams that another solution would be another guide like the one on the bottom side so the chain can't bind up when it breaks. Just a thought[img]i/expressions/face-icon-small-disgusted.gif[/img]

Cracked transmission case.... Don't want to do it again
 

Polaris now manufactures a much beefier side case (which will bolt up perfectly to the older left hand side). This new case half is also drilled and tapped for a polaris-made chain guide. This chain guide only allows enough room for one pass of chain to go through at a time. In the event of a chain break, the chain is simply fed through the guide without harming the case half. I know this because I cracked a case half and replaced it with the newer case half. This latest designed case half came out on the 2002 model bikes, and applies to xplorers and scramblers and all other chain driven quads.

Waylan

Cracked transmission case.... Don't want to do it again
 

Really? When I was getting quotes for the case half this spring they asked me if the machine was made before or after 4/01 (mine is pre-4/01) So I didn't have a choice on the case. Is the case guard plastic? The case I got did come with tapped holes and I was able to put the plastic case guard off the orginal case onto the new one, but it still allowed the chain to wedge and break the case a second time. I will for sure ask the dealer about the new case and guard. Thanks!