'79 DOHC Charging and Fuel system ????

[Schlutt]

Good afternoon. I've been lurking for a couple of months and I appreciate all the information that I have seen so far. I am new to riding and I got first bike about four month ago. I got a '79 cb750K DOHC in a trade that was too good to be true. The bike rode great for a while then the trouble started. I am having fun/frustrated rebuilding one bolt at a time but I encountered the typical charging issue that many run into. I have replaced the wiring harness, rotor, stator, regulator/rectifier, starter relay and turn flasher. After all that it looked like my charging issues were solved. I saw it was charging over 14v.  

I then took it out for a ride and had carb issues so I had to rebuild them. The bike had been sitting for 30 years or so, so I'm not surprised things are failing. However, today after getting the carbs back on and giving it a test ride I let the clutch out too fast and the engine died. (we have all done this). I didn't nothing of it except the bike wouldn't start. After pushing it back to the house I tested the battery at the posts and it read 13.25v which should be plenty of juice to get rolling but I all heard was a click.

Any advice would be greatly appreciated.    

[TOOLS1]

"I let the clutch out too fast and the engine died. (we have all done this)." I have never had that problem.

A click? Sounds like the starter might have went bad, or a cable connection to the starter.
TOOLS

[18Bravo]

Push start it. It will fix absolutely nothing, but you'll be able to sleep knowing that it can't be that bad if it still runs. Plus it's good exercise.  :)

[Schlutt]

Tools,

I check and replaced what I thought was a bad connection. However same song and dance. I heard a little whine from the starter but then all I heard was the click from the relay. I am guessing that it must be the starter that is going out. Is there a way to rebuild it or do I need to just get a new one? Or do you think that this can be fixed with a new set of brushes? It sounds and feels like its not getting enough power but the battery read 13.5v before I tried to crank. Please advise.  

[TOOLS1]

If the starter is "whirrring" then the starter drive is not engaging, which is a common problem on the DOHC engines. Parts to re-build the starter drive are available, and it is not hard to do. I would do a search here for "starter drive" as I know others here have done it already.
TOOLS

[LukeM]

1.  Pull the starter from the bike.
2.  Secure the starter in a vise or to a large block of wood.
3.  Locate a pair of jumper cables and a 12v battery.
4.  Connect the MINUS side of the battery to the case of the starter.
5.  Touch the PLUS side of the battery to the PLUS terminal/cable on the starter.

The starter should spin freely.  There will be a lot of torque when the starter spins up. This is by design.

If the starter works fine, the problem is probably with the starter drive.  The bolts securing the starter overrun clutch to the crankshaft often come loose. They did on mine.  

If the starter does not spin freely, it may need to be rebuilt.  Kits for this can be found at most Honda parts stores, aftermarkets, or online stores.  There are YouTube videos of diagnosing and repairing these parts.

Good luck.
Luke M