Dr 650 running rough at altitude

[endur0dewd]

I recently moved from Buffalo, NY to Salt Lake City, Utah. I purchased my dr650 about a year ago. The guy I bought it from had it jetted and I think he had it jetted a little too rich even for buffalo. Now that Im in Utah and much higher in altitude the bike is running terrible. I've searched the forums and picked up a lot of helpful info but not sure on two things.

A. I wanted to try to adjust the pilot screw...Im aware I have to drill through a brass fitting, but how? There is no space so do i have to remove the carb to drill out of cap?

B. To adjust the jet, if it is already 'jetted' is there clips I should see?

[Craig in Denver]

I recently moved from Buffalo, NY to Salt Lake City, Utah. I purchased my dr650 about a year ago. The guy I bought it from had it jetted and I think he had it jetted a little too rich even for buffalo. Now that Im in Utah and much higher in altitude the bike is running terrible. I've searched the forums and picked up a lot of helpful info but not sure on two things.

A. I wanted to try to adjust the pilot screw...Im aware I have to drill through a brass fitting, but how? There is no space so do i have to remove the carb to drill out the cap?

B. To adjust the jet, if it is already 'jetted' is there clips I should see?

A. If the previous owner had it jetted, the pilot screw cap has been removed. To check you'll need a mirror, look up under the carb (engine side of the float bowl). If the brass cap is there, I think you can loosen the carb clamps and rotate the carb to drill. Don't force anything, you don't want to kink your cables. I don't completely remember, it's been 6 years. I do know the carb cables were never undone, so I may have twisted the carb loose of the boots to get at the cap. Be careful, that cap is thin. When the drill 'bites', it will go right through and try to damage the screw head. My screw is 1-1/3 turns out at 5800ft alt. You'll need more, 1-1/2 maybe?

B. If it is already jetted (with a jet kit), the needle will have 5 notches on the top. Note the notch where the e-clip is, move the clip UP 2 notches, as a guess. This will lean you a bit and get you started. If only one notch, there may be a spacer (small, thin washer) under the e-clip. If it's .040 leave it. If it's like 1/8" or more, replace with an .040. Main jet 140, stock; 150 with a jet kit. Careful, there are two different jetting sets, stock and aftermarket. I guess if you have a 5 notch needle, the main jet will be a 150 or larger; maybe.

If you're lucky the four carb screws (2 top, on the plastic cap; 2 bottom, on the float bowl) will be allen heads and easy to remove. If they're phillips heads, you'll be better of with an impact tool, to loosen those 4 phillips. If you aren't a 'garage guy', those 4 screws will give you heartburn.

The snorkel should NOT be in the top of the airbox, if it is, pull it out; simple and reversible. If it's gone or a large hole is on top of the airbox, don't panic, it will work.

Good luck, come back with questions ?

Too much info here, bring a lunch:

http://www.advrider.com/forums/showthread.php?t=347184&highlight=bst40