QuestionHELLO,MY CB 750 SEEMS TO RUN A LITTLE LEAN.ALWAYS RUNS BETTER WHEN THE CHOKE IS A LIITLE APPLIED.TO CHECK ALL 4 ADJ SCREWS ,WHAT CAN I MAKE ALL 4 AS A GOOD STARTING POINT.HAVE NEW PLUGS,PS IS THERE A SPARK TIMING TO BE CHECKED? THANKS MIKE
AnswerMike,
hondas seem to need a warm up to run well.
Try starting with the screws a couple of turns out,
turn them in until the engine falters, then
go out a half turn or until the engine
runs smoother. You may have idle jets
that are getting plugged up, you could
try some additive like "Seafoam" or
a carb clean.
-If it has always been lean, you could go
up one size on the idle jets or
possibly the carb needles could be
raised a hair to richen the fuel mixture.
-Timing is electronic I believe,
not much to check. If it has a mechanical
advance unit that can be checked
and you can hook up a timing light
to see if it fires on the "F" marks.
You have to remove the small side cover
on the engine to check these.
I would just leave the timing alone if you have spark
and the bike is running ok. It is likely
the carbs that cause the lean running.
-Make sure your tank petcock and fuel filters
are clean. The petcock valve has a little
rubber diaphragm that can go bad and also filters
that can plug up.
-check around the intake tubes for any air leaks,
this can lean the fuel mixture.
