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last summer i had a v&h full system installed with jet kit and k&n filter. after i got the bike it ran like shit so i took it back. second time i got it back it ran better but around 4500 it seems to surge at a steady speed. also if i whack the throttle between 4-5 grand it bogs real bad.. the mechanic said he needs to raise the needles another .5mm does this sound like it would take care of my problem. one more thing when it is cold and you rev it up it will backfire thru the exhaust and shoot a pretty blue flame out the exhaust about a foot.

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92 blue and white 1100
 

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surging usually indicates a lean condition, but a vacuum leak somewhere would also cause that. does your bike still have the airbox, or do you have individual filters. i'm thinking, maybe he put on individual filters for you but used the smaller stage 1 jets from the jet kit - that would cause your bike to run way lean.

but, it could be any one of a number of problems. did he use the right jets, did he set the correct float heights, did he make sure that the slide diaphragms weren't pinched when he reassembled the carbs, did he use at least one of the slide speed restrictors in each slide, do you have clean gas in the tank, etc.

as for the bike spitting when revved up cold (btw - don't do that, let the motor warm up fully before revving it), again, it sounds like a lean condition, but also maybe a bit of air is getting into the headers. the exhaust gaskets need to be replaced whenever you remove and install an exhaust - they get flattened when the exhaust is first installed, so if you try to reuse them, they might not seal well, and air'll get in. mix the air in with the exhaust and you'll get lots of popping and spitting.


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In addition to the items Jeff mentioned, one of the largest contributors to throttle response for that set of carbs was the slide speed. It is noticed most when you whack them full open and more pronounded down low in the RPM range. If they are off, it will either rev up to slow and you'll get a bit of fouling (too slow a slide speed), or it will fall on its face then get going (too fast a slide speed)

DJ had many different set-ups since '89 and the base one was a bit on the slow side. They adjust the slide speed by using small orifices that screw into the slide holes (comes with a tap and some orifices). They put different ones in the kit depending on what your doing.

So make sure they were put in, you dont want to use the stock slide holes as it will lift to fast and give you a stumble. The best setting I ever used was the small opening on both vs small with one plugged which they recommended in the beginning (later changed to 2 small ones).

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