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32mm Mikuni Flatslide on XR250 tuning help

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Just installed this carb. Today was the first ride.

The bike :

2001 Honda XR250

Opened airbox, header welds ground, UNI airfilter, FMF exhaust, stock cam and bore.

Halifax Va., 494 elevation

Symptoms :

Bike cranks well, idles well, when slowly using first 1/8th of throttle it stumbles and does not idle well, sometimes almost dies out(on flat pavement mind you). Improves when warmed up more. Bike runs kind of flat 1/4 of throttle and accelerates well in the upper portion of the throttle. Runs better when accelerated more quickly. Tried a bit of slow tight woods maneuvering from sitting still to try and tractor. The bike would cut out. Had to turn idle up and use throttle and clucth more than usual.

Thoughts :

I was thinking it was perhaps rich. Over carbeurated. No real experience doing tuning but have done some research. Called XRsonly that I got bike from. Tuner said it came set for elevation of 3200 feet. Paper sent with carb gave the following informaiton.

Carb settings :

195 Main Jet, 35 Pilot Jet, 2.0 air jet, a 6DH3 Needle(clip in middle position) and 0-2 neelde jet (nozzle)

Carb came with aditional jets higher and lower.

Here is a pic of the plug. I pulled it after doing some riding at the upper rpms then taken down to low rpms.


Before getting into the carb the only thing I have tried to adjust is the air/fuel screw which seems to run best at its initial setting of 2 1/4 turns out. Idling and cranking becomes difficult if turned in or out.

My question is since it seems to be running rich should I first change out the pilots or the clip on the needle? Harescramble on Sunday so hoping to get this worked out. Any help would be much appreciated. :thumbsup:

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