View Full Version : Evo sporty runs like shiat. 1200, mikuni, etc.

09-19-2009, 9:28 PM
97 883 XL. SE 1200 kit, 10-1 comp. Thunderstorm heads, SE 497 cams, HSR42, SE ham can air cleaner, SE 2n1 exhaust. Issues are wicked flat spot off idle till 2200rpm, popping thru carb at idle and on accell, loud popping thru pipe on decel. Often times when first started it'll crank a few times and backfire, like a .45cal out of the pipe, then start. Lately it's started dieseling when I shut it off. No matter the bikes temp or air temps, these problems persist. No intake leaks or exhaust leaks, new tune up parts too. Any directions on where to look would be helpful. This thing is soggy as fuck off idle and I know it should snap alot harder, hell my stockish 80in Evo hazed the tire from stoplights at will, and this thing won't do a burnout in a mud puddle

09-19-2009, 9:43 PM
Has your ride just started doing this?

09-20-2009, 12:26 AM
ignition related would be my guess. check the coil(s). check timing. voes switch?

09-20-2009, 11:18 AM
Yeah I doubt its the carb.......mikuni's are supposed to be the shit on sportsters.

09-20-2009, 11:45 AM
Well if it didn't do it b4 you took it apart for powder coat and it has the problem now I would start at the battery then the grounds. If it is dieseling when you shut it off that usually indicates a high idle setting or a vacuum leak cuz in order for it to diesel xtra air has to be introduced from somewhere.

09-20-2009, 1:39 PM
It's had these issues since I got it, well before the powdercoating. No voes switch, it has a SE ignition. I always heard Mikunis were the shit, but this one is a pain in the ass. It runs good when I leave the choke on, no popping on decel and idles pretty good. this mean it's too lean and the choke is richening it up to where it needs to be?. It has the leanest needle in it now on the 2nd clip, it was on the 4th clip and would barely run at all ..I'm gonna try to find a richer needle and start there I guess.

09-21-2009, 11:01 AM
Has the mixture plug been drilled out ?

09-21-2009, 1:53 PM
nothing is touched, it's straight out the box. Thought I had it figgered out. The bowl screws were hitting the cyl fins and not letting the carb slide all the way onto the manifold. Ground the fins down and fired it up...still does the same shit. With the cleaner off and the bike idling, I can see fuel misting in the venturi. Then after about 10 seconds it'll pop a small flame in the carb, sputter and die. Wondering if I have a valve issue, maybe not seating all the way and reversing back into the intake??