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Old 11-10-2006, 09:46 AM   #18
wickerman777 OP
Canyon fodder
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Joined: Jul 2006
Location: San Francisco
Oddometer: 314
Ok so my initial jetting though it increased power and acceleration dramaticly was causing some annoying running issues. I've tried a number of main jets: 135 and 140 mikuni mains and shimmed the needle. The pilot jet is still the stock 40. Well it is running excessively rich at idle even with the stock pilot and a completely opened airbox and pipe. Upon aggressive acceleration it performs great with lots of torque and it moves quickly up to freeway speeds. But the minute you back off even slightly to slow or maintain speed it begins to exhibit the cutting out/bogging symptom.

I am going to remove the shim as that should be the only thing that would cause such a rich idle condition at this point and see how much of a difference it makes. I'm also going to go down to a 130 from the 135 in it now.

I think the biggest problem is the needle though. I've jetted alot of bikes and am pretty familiar though nothing this small. It reacts very strongly to relatively minor changes. I think the needle taper is just to....? As it's coming up under heavy acceleration fuel delivery is constant and smooth but the minute you back off even the slightest it seems to just cut off the fuel completely for the amount of air being introduced. I'm going for max power across the range though so taming it back down towards stock settings though it would solve some of the problems is out of the question. Noone makes a jet kit with a needle for this bike though. The difference between the stock needle and dynojet needle on my DR was amazing. You could just feel all the flat spots with the stock needle and wonky accel/decel characteristics. Just looking at the dynojet needle compared to stock it becomes extremely obvious why. The taper is just plain smoother and less aggressive all the way up as in no sharp taper changes.

Today I go to Factory Pro in San Raphael to throw a bunch of money at a butload of jet and needle options to experiment with. I think if I can get the right needle in here then the rest of my jetting can go smoothly.
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