I have an 05 1200 carberated sportster with the screamin eagle kit.

heres the symptoms:
1 Does not require choke to start up.
2. Runs like it is choked
3. Runs great under acceleration but not at cruising speed
4. Spark plugs are very black and suite, so is inside tip of my exhuast
5. does not use any oil
6. gas mileage has gone to hell
7. Back fires through the carb

I have pulled the carb off the bike, and cleaned up the choke and inside where the diaphrame is on the carb. Put it all back together and still no change.

Any help or suggestiions would be greatly appritiated and thanks in advance.

 

hmm. sounds like your running rich man. I would check basics. Plug wires & distributer (although those dont really fit in to the great under accel part). But Check them any way. Continue with your tuning screws on the carb, they may have been messed with.

 

floats stuck?

 

What mods with the Screaming Eagle kit?

Did you mod it or buy it that way?

What jetting does it have in it now?

Is the Air/Fuel screw already exposed?

How does it run or start with the air cleaner cover and filter removed?

 

the bike will idle like it should with air cleaner off or on.
I have not rode it with the air cleaner off.

The only time my bike will run poor is at cruising speed weather its at 30mph or at 75mph.

I bought the bike with 230 miles on it from a guy that had the mods done.
I know it has new pipes and has been rejeted. what I believe is the stage one kit.

I know the bike is running rich, and i have adjust my air/fuel mix screw and it does not seem to make a difference.

By the way guys here is one more problem if i havent mentioned it before.
I do not have to use the choke to start the bike when it is cold. I hear that the 1200 should need choke to start and run.

thanks for all your input so far, the bike is at the shop since yesterday, but when i called even they didnt know what was wrong with it.

 

yea sounds like some pro's need to look at it. thats some messed up ****.

Im thinking something on the inside screwed up.

 

Check the obvious.
runs like crap at idle,,doesnt need fuel.
Either the pilot is too rich or it isnt in at all and is sitting in the bottom og the fuel bowl,or the person forgot to put it in.

Check floats,check needle and seat,,check most importantly petcock diaphragm.

 

+1 on the pilot jet being way too big or missing. With the standard SE package (exhaust & A/C), the pilot jet shouldn't need to be any larger than a #45.

 

Agreeing with Charley He knows his Sportsters ... Has bailed me out of trouble more than once when comes Sporty's

 

You should also check the enrichener cable and valve if they been apart and not put back together right or of it's stuck that can cause your problems.
It is also almost 5 years old and if it sat around with the same gas in it for a few years, you may need to pull the carb and really rebuild it, not just squirt it with some carb cleaner, a build up of varnish in the wrong spot can cause all forms of problems.