BOMBARDIER DS650 DS 650 JE 720CC BIG BORE CYLINDER KIT - eBay (item 230589495728 end time Mar-01-11 16:51:08 PST)

 

Seems like the word out on those kits are some people have some trouble keeping headgaskets from leaking. They are a stock cylinder with a pressed in sleeve. I hear from the people on the forums that once you bore the cylinder big enough to press in the sleeve there isn't much left to hold it in place. I keep thinking about them too but I just can't pull the trigger. If you buy one I would sure be interested in the outcome of the build. I do not have any first hand knowledge of these statements this is all just from searching different forums. Hope some of this helps.

 

I had no luck with mine. Leaking gasket was the culprit, I have also heard of them lifting up a bit. Your best bet is to get on nomercyracing and find a good shape OMW 730 kit, there is a Pami jug on there now.

 

Eric at OMW is the only way to go brother, those ebay kits are no good

 

OK guys thanks very much for the input.

I recently purchased a used DS with a 720 kit, and low and behold.. the motors shot.

(didn't realize until the first time out in the desert with the bike... Cant tell riding it up the street before purchase)

The cylinder itself has separated from the sleeve in one spot, creating an out of round cylinder.. and the piston itself was broken in between the rings and the pieces were just along for the ride. When I removed the cylinder, the pieces that were trapped between the 2 comp rings, but held in by the cylinder wall itself just fell out.

So, no 'replacement' 720 kit for me. Either a used 730, or a stock cylinder and JE 11.5:1 piston.