Motorcycle Repair: 1984 sporty ironhead, open pipes, straight pipes

Question
QUESTION: i just bought a 1984 ironhead sporty, the previous owner claims that the motor was rebuilt, but he had problems tunning, here's my problem, the bike has alot of backyard work done, it has a mikuni carb, and straight pipes, the bike runs fine once it gets going, sputters alittle on the low end, but top end is fine, starts and idles fine, but after deceling from cruise the bike stalls, i look down at the inline fuel filter and looks empty i also noticed there was no breather in the tank, i drilled o hole in the gas cap, and it seems to run a little better, but still stalls at a stop sign, also the petcock from the tank seems to sit lower than the fuel line is routed could this be a fuel delivery problem? could this be a jetting issue with the open pipes?? very frustrating

ANSWER: Pull your spark plugs and let me know what color they are
Mike

---------- FOLLOW-UP ----------

QUESTION: front cylinder was light colored white/brown, the second cylinder was black, also i put a compression tester in with open throttle in 5 revs i had 120 psi in both cylinders

ANSWER: Once a ironhead is rebuilt, you really shouldnt have a problem tuning it.
When you did the compression test was the motor warm? What ignition are you running (points or electronic) the carb you are running, is it the new style or the old orgional style?
Mike

---------- FOLLOW-UP ----------

QUESTION: the motor was cold when compression tested, the carb on it is Mikuni VM round slide carburetor. i do not know what type of ignition it has, how do i determine, should i re-do the compression test with a warm engine? i have done nothing to the bike since i aquired it, i am new to harley's but was a car mechanic, i am learning quick that they are not the same sport.  

Answer
Do your compression test with a hot motor. Also, do a bleeddown test.
I am not familar with the mikuni round side carb, never worked on on since they are not very popular. They are a vintage carb. If it were me, I would switch it out for a S&S carb.
to see what kind of ignition you have go to the cam cover on the right side of the bike. you will see a small cover with two screws. remove the screws and under it you will see the ignition. It will either be points or electronic. let me know
Mike