Motorcycle Repair: carb problem, 1982 honda nighthawk, little squirt

Question
I have a 1982 Honda Nighthawk (cb450sc). It runs, but
doesn't have good power, and doesn't accelerate well at all.
It can hardly take off even on a slight incline without
really revving it. Choking it helps some, but doesn't have
the zap it should. I've have carbs apart and cleaned them as
well as I can, soaked em and blew em out. Also have cleaned
the jets several times. There's one very small fuel passage
in the accelerator pump cover that is clogged and I can't
get any air through it no matter what I do. Does that have
any bearing on the problem? One guy told me I maybe should
get new jets but they seem to be fine and I cleaned them
well. Any ideas?

Answer
Andrew, the accelerator pump is there for a reason. If it isn't spraying a little squirt into the air stream when you crack the throttle open, then the engine will fall flat on its face.

Check your carb needles for the updated parts, too.

http://www.hondanighthawks.net/82_450_CarbSB.pdf

I have found that increasing the primary main jet about one size will help that mid-range flat spot, along with the needle changes.

You still need to fix the accel pump, though.

Make sure that the air cut diaphragm is still okay, too.

After you have solved the carb problems, check the spark plug caps for 5k ohm resistance values, unscrewed from the plug wire.

Bill Silver