QuestionHey, i recently bought a honda vf 750 1983 sport, when i bought it the carbs were off the bike but i re-fitted them after blowing the carbs out with a compressed air line, and re-set the float heights. when i put it back together it start first time but run for around 30 seconds then it stopped dead and will not re-start. or fire at all. but if u leave it overnight and then turn it over it'll sound like it fires once then it goes back exactly the same just turning over. i've replaced the sparking plugs, and their all sparking with a pretty good blue spark, theres plenty of fuel in it and the fuel pump i putting plenty of fuel into the cylinders. my thaught is electrical problem. does anybody here know what it could be n what i should look for?
thanks alot
AnswerLee,
-How is the compression on the cylinders?
Should be 150 psi or higher.
-When starting it's not likely an electrical problem if
you have a good spark.
-Have you tried some wd40 or carb cleaner
in the carb mouth, see if it fires on that.
-If it does then you still have fuel problems.
-The fuel pump usually runs for a few seconds
when you turn on the key, can you hear it?
-the carb jets have very small holes and
also have to be removed and cleaned carefully.
-The passageways under the jets can be plugged
and may need to be soaked or cleaned well.
-Few people clean their carbs well enough,
the small idle and main jets prevent
fuel from reaching the engine.
-make sure the float bowls are
filling with fuel, see how much comes
out if you drain them.
-fuel petcocks can go bad as well
and prevent fuel to the pump.
-if your problem were no spark then I
would be looking at the pulse coils and
spark units or modules.
-Make sure battery is fully charged and
cables tight.
http://www.kabalis.com/SuperMagna/ServiceManual/
