I have an 01 DS650 and lately it runs like crap I never touched the carb from last winters settings it ran ok the few times I rode it this summer. But lately it seems to have less power from about 5500 rpm on then it used to. I got my *** handed to me by a banshee numorous times. on a drag strip on the ice. I figured it was just a carb problem so I cleaned it up and inspected it all seemed good including diaphram. put it back on and still the same. The guy I bought it from last year said he never did a valve shim job so the otherday I pulled it apart and checked the clearances. The exhaust was .007 and the intake.004. I read that the clearance should be between .004 and.006 but is this for both intake and exhaust?
From my expieriance the exhaust ushally has a larger clearance than intake. I thought that the clearances would have been lager being that the bike is 7 years old and has been riddin quite alot from the previous owner and then I put like 500 miles on it since I have had it. One thing I do need though is a new idle cable/screw because the one on the bike is rusty and does not turn very easy, but I do not think that this would cause my problems. Any info would be great.

 

Check the Carb first. Open it up and clean it all out. Clogged or dirty carb will make any bike run as you described.