Motorcycle Repair: Carb problem, mikuni carbs, air screw

Question
QUESTION: Wayne, I have a 1976 Honda CB360T. I have new 32mm mikuni carbs. The air box and exhaust has been modified. The new carbs came with a #35 pilot jet, I have changed the pilot jet to a #25 and I'm still having problems. When the bike starts the idle runs up to 4000rpm's and then settles down to about 1200rpm's. The bike will run for a couple of minutes then it stalls and will not start again. After it stalls, the plugs are very wet and after cleaning the plugs it will start again and do the same thing. Please let me know what I should do next. Thank you for all your help.

ANSWER: James,

-What kind of choke system do you have?
If it is plungers the plunger needs to be down
for normal running. The pilot screw on
these is usually an air screw, turning
it out makes it leaner (more air) and in makes it
richer.
-Are the cutaways on the slides
facing correctly backward? Sometimes people get
the left mixed up with the right side. This
would cut the air off and act like a choke.

-Make sure the slides close and open at the same
time. Adjust the cables as necessary.
-Are the slide needles firm in the slide held
down by the clip and spring?
-The float may have to be adjusted to close
the float needle valve sooner, lowering the gas
height in the carb bowls.
-Set the pilot screw about a turn out to start with.
-Have you checked the compression on this bike?
If it is at least 130 psi, it might be okay.
If it is less, the engine may need top end work.
Good luck!


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

QUESTION: Wayne, when you say the plungers need to be down is that the choke lever in the down position or in the up position. One of the slides has a dimple in it on the oppisite side of the guide pin groove, the other slide does not. Is this how you determine left or right side?

Answer
James,

-if your choke lever is on the carbs,
usually the choke lever goes down and the plunger
goes up for choke.
-Lifting the lever should push the plunger down
for normal running.
-Just watch what happens to the actual plunger,
if it is up, that is choke, down to run.

-look at the bottom of the carb slide,
on one side it will be cutaway in a curved
shape. This cut part goes to the rear or
intake side of the carb. If the guide pin
groove doesn't line up, switch the slides
until the slide will go into the carb with the cut portion
facing to the rear of the carb or bike.
I can't say if the dimple on the slide
means anything for sure. Just go by the
cutaways on the bottom of the slides.
Sometimes they used dimples for adjusting
the oil pump setting on 2 stroke bikes.