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CB750K no spark

travis98146

CB750 Member
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Burien, WA
Last month I posted about a 1981 CB750K with no spark. No one could tell how to check the spark units that showed signs of overheating (not even my dealership). I acquired a factory service manual that gave detailed test procedures for the entire ignition system. I now have spark from both coils and will add fuel and try for a start-up today.
 
So the coils tested good? How did the start-up go?

After adjusting spark plate and air gap, it tried to fire. Using starting fluid, it would fire all 4 cyls. I managed to get it running on #1 only. No fuel getting out of the other 3 carbs. Carb cleaning time. FYI, with the service manual, pulse generator, rectifier, CDI units, coils & plugs all checked out OK.
 
Wow i think we need to do a basic check list of start up procedures for bikes that have sat 4 an extended period of time. Isnt that cleaning the carbs would be right near the top of that list. Anyway live and learn its all part of the fun!...Doug
 
Houston, we have ignition! After a carb cleaning and a rebuild on the fuel shutoff valve, the 750 runs. Now it's time to re-do the timing and clean the vacuum fuel shutoff valve.
 
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