Kansas, yeah its a cv carb with dyno jet kit. I dont know what all was replaced or changed before I bought it so I am going to pull it off again tear it down and see if the guy I bought it from did all what he was suppose to with the dyno kit. Ill check everything again to make sure it has all the right parts. Murphdog, Ill try a smaller jet and try the stock needle. Is there any way that something more internal could be wrong? Somebody mentioned timing but I would think that if it was the timing, it wouldnt run as good as it does before fouling the plugs, but im really not sure. thanks again guys...
BTW...I also checked the petcock according to the manual and it seemed ok. so i think i can rule that out...

 

I agree with Murphdog, put in a 42 slow jet first, especially with that DJ kit.

OR..... another thought that just hit me....

if the complete DJ kit is in there, the needle is adjustable, you could try raising the clip a notch or two, leaning out the midrange, which seemes to be where you are fouling plugs........


K.

 

K, not sure what the theory is behind the Dynojet emulsion tube. They have a bad reputation as far as mileage goes though. I put a DJ kit in mine shortly after I got it and couldn't get decent mileage no matter what I did with it. You probably know, but the threads for the main jet are different than the Keihin tube.

 

If the idle mixture screw adjustment makes no difference, that means your carburetor is not adjusted correctly. You are idling with the throttle too far open and the idle circuit isn't doing it's job. You have to fix this before you rejet (you may not need to rejet).
Set your mixture screw about 2 turns out to start. With the motor warmed up and idling, turn the idle down using the idle screw. Turn the mixture screw in until the idle starts to slow even more, then turn it out until you get the highest rpms, but no further than that. If the idle is high, turn it back down using the idle screw and repeat the adjustment with the mixture screw.
Your goal is to have the mixture screw open only far enough to give you the highest idle rpms and if you turn it in even a quarter turn, the idle slows (you may need a tach to see it). Your desired final idle rpm can then be set with the idle screw.

 

kansas, i pulled the carb again. when I pulled the needle it has the e-clip in the 5th groove down (from the flat side of the needle) it also had 4 small washers on top of the e-clip. (closest to the flat end) I dont understand why he did this if the e-clip is adjustable. Should the even be any small washers in there? If I move the e-clip up closer to the top it should lean it out a little right?

 

By raising the clip towards to the top, you are lowering the needle which will lean out the mid range.
If the washers were in between the needle clip and slide(raising needle),sounds like the PO was trying to richen up the carb.
And BTW,its hard to concentrate with the Avitar you have!

 

1FLTRI4ME is right, about the carb too!!
and so are you, move the clip to the 3rd from the top (flat end) the washers are there to keep the needle tight, from bouncing up & down, so the spring locater puts tension on it, you want the washers to be about flush with the top of the needle but not over, with my clip on the 3rd slot, I have 3 washers on top, you're almost there, don't give up!! so to re-cap, here's what I would do,
put in the 42 slow jet, start out 3 turns out on the mixture screw, put the needle clip on the 3rd slot, with 3 washers on top, and a 180 main jet, which should be plenty big because the instructions for my DJ kit for a TC88 says "use the DJ 180 main jet with an aftermarket exhaust, or airbox. with AM exhaust, airbox and cams, use the DJ185main jet."
leave everything else as it was and try this set-up first, if this don't work, we'll go another route.... similar to Murphdog's set-up which would be stock needle shimmed up (underneath the head of the needle) with 2 of those small washers you have, or un-shimmed sporty needle, 42 slow jet, stock main jet holder with a 180 keihin main jet, un-drilled slide, stock or DJ slide spring, the DJ spring is supposed to be softer, so the slide will raise quicker and sooner.

good luck and let us know how it works out,

Kevin.

 

I guess I misunderstood the washer thing when I posted.

 

I don't think you can modify a dyno-jet kit, or a Yost powertube or any other carb kit so that it won't be too rich. Your best bet is to go back to the stock carb, put the 88-89 1200 Sportster needle in the stock idle jet and leave the main jet stock. At your elevation you may have to go one size smaller on the main jet than stock. Or go to a Mikuni 42 and tune it according to their website.

 

Ok, I put the clip on the 3rd slot from the top three washers on top, 42 slow jet, 180 main jet, 3 turns out on the mixture screw, and changed the spark plugs... Started it up and ended up adjusting the mixture screw to 2.25 out, any lower and it wants to die, any higher and it idles rough. Everything seems good, idles good and quick response.. I took it for a ride for about ten minutes to get it nice and warmed up. Got it back, pulled the plugs and they were coated with carbon soot. Running rich? Then I put a 175 main jet, 42 slow jet, and new plugs, took it for another ride about ten minutes, got home pulled the plugs, looked the same as the last ones, carbon soot.. No matter what it seems to want to rum rich.. It runs good and response time is good but it just turns the plugs black...

Lost....


--EDIT--
I just took it for about a 30 minute ride, it seems to run great, more power than before and better response... The only thing is. When I take off from a stop light, I noticed when the throtle is just a hair off idle coming up in speed it seems to be just a little rough, (sluggish) just for a second. But after I pass that point it runs great. Any ideas on this?

Thanks