Motorcycle question?

Question

I have a 1978 Honda CB 750k. It has recently started to run a little rough at times. I think that the coil is going out but to replace them is going to be about 200 dollars. I was going to rebuild the plug wires first. Anyone know a link that would show me how to do it or that has done it themselves?

Answer 1

First 3 answers are good.
Many things can cause rough running, including a low battery.
Clear your fuel system, and do a tune-up as suggested. While you're doing this, do a basic check on your electrical, look for loose wires, bad connection, etc.

The CDI unit usually goes before the coil.

Answer 2

I h ave replaced the plug wires on the 750 coils. I may even have an old set of coils in my garage.
Let me know if you need specifics. That said, I do agree with the above, make sure everything else is functioning,before we go after the coils. But those coils did tend to go bad and the wires DO break down.

Answer 3

Your first answer was good advice. Forget about the coils, people are way too quick when suspecting coils, coil failure is extremely rare. Regarding the plug wires, unlike automotive wires which are carbon impregnated fiberous material that breaks down after awhile, most motorcycles use solid metal wires which last forever. Start with a thorough tune-up, if that doesn't cure your problem, THEN its time to start looking for specifics.

Answer 4

You need to do some diagnostics. 29 year old motorcycles are more likely to suffer from dirty carburetors than ignition problems. or dirt/water in the tank. make sure to get fresh clean fuel in her before you start replacing other things. i think you will find carburetor bowl drain screws on the carbs - too. should run some fuel out of them to flush out dirt/water. take usual precautions to not blow yourself up.

Answer 5

Rough at times....before I spend any money, check them coil brackets, to see if one of them is cracked.......