Cb750 Electricals

jstark21

New Member
Okay so I just bought a 1978 Honda CB 750F

I took off the carbs to give them a good clean job, as well as the rest of the engine. However, after being put back together I started it and it would idle for a little bit at 1000 rpms and then little by little slow down and and drop rpms to about 500 until it dies.

I would then try to start it again but the battery would be very low on juice and kick starting won't even work.

So obviously something is wrong on the bike, and it is driving me crazy. I was thinking about getting a battery elimination kit and dropping a capacitor in it to shed some weight and give a cleaner look. Would this rid me of my problems?

Could there be a fault in the charging system?

I just need some good input and thoughts on what direction to take this thing in

???
 
If you can't make it work stock modifying it will only make things more complicated.

First these bikes don't start with a dead/low battery kick or not.
Second get a manual and go through it. It will walk you through tuning.
Third I don't know of any sohc that runs without a battery, save a magneto ignition.

Based on the little info here are some possibilities
-weak battery
-bad charging system. This could be a bad stator or rectifier or regulator or just a broken wire.
-wrong settings on any one of a number of things in the carbs.
-user error, you aren't leaving the choke on right....
-failed petcock
-cracked coil
 
How is the battery? New or old? Could be the battery or charging system is going. How much choke are you giving it when starting? On my '77 CB750K I have to pull the choke all the way out when starting and then almost immediately push it back in to half way, once it's warmed up a couple of minutes I ease it back in and it runs great. Have you tried turning the idle speed up a little? Try one thing at a time to isolate the problem.
 
onetruepunk87 said:
...I have to pull the choke all the way out when starting and then almost immediately push it back in to half way, once it's warmed up a couple of minutes I ease it back in ...

:eek: :eek:
 
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