QUOTE(NyTrOMaNIaC @ Dec 15 2007, 06:36 PM)

He should be able to use the 1+1 seat as long as it has the rear opening plastic trunk still attached and not the X seat from 04 and up. Keep in mind that not all compression guages are the same, but acceptable compression should be no lower than 130 psi per cylinder, (although I've heard of guys still riding on 120) but 140-145 psi per cylinder is top notch ! (someone correct me if I'm wrong)
Good Luck !
I know of a guy who did this and had to buy a couple of brackets from a Non-X model to make it work. Dave is right on the compression. The 800's rings are known to flake. Also check out the PTO seal. They're another problem which can lead to bigger problems.