Help me.. It won't start and its nice out!

[Greywolf43]

I have a 1979 CB750K. Stock. This year, after fully charging the battery, and setting things up so it can be taken out for some two wheel fun, I attempted to start the engine. The engine turned about 1/2 way and stopped, Now all I get is a clicking noise from the solenoid and nothing from the starter motor. I truly suck at electrical problems, and am hoping someone can help me out. I've checked the wires that I can easily access, and i don't see anything loose or corroded.

In short, I turn the key, and the solenoid clicks rapidly but the engine does not turn. The lights dim when I do this, and spring back up afterwards. (This is true even when hooked to a car battery) Any helpful suggestions would be greatly appreciated. It has run fantastically for 20+ years that I've owned it, and no starter problems for 70,000+ miles.

 

[Greywolf43]

An update. I've tried bridging the solenoid to see if the motor turns, and it does not. It makes a tiny bit of noise, but doesn't move. As this is the first start of the season, the bike will be virtually impossible to start via a jump start. Any help would be appreciated.

 

[amc49]

You gotta have a known good battery before you can crank anything, simply charging one doesn't mean spit. The car one could be bad or too low also. What the clicking is telling you. No voltage at the starter and not at solenoid too.

Loadtest either one of the batteries, they'll be likely dead. Or issues with your wiring harness. Auto parts stores do loadtest for free commonly now. You can turn the engine over to make sure nothing has locked up on it, use the right side of engine at alternator.

People use cheap crap low dog low price jumper cables and why they now have so much trouble jumping off things. Use either bigger cables or two cheap sets one on top of the other and you can jump off things all day long. Cheap cables do not have enough cross-section metal at the clamps to carry enough power to jump properly. I came up with that trick at the parts store when so many people bought cables right there on the spot and they then could not jump car or truck to get it off the store parking lot.

Battery needs to be 12.3 volts or higher or dead, they commonly give trouble at lower volt than that, brand new battery around 12.8 volts. 12 volts even is an utterly dead battery. Measure it after charging and then letting it sit one hour at least to remove surface charge. Surface charge is charge not soaked into the plates yet and a higher number that fools you into thinking battery is good when it's not. Why after fresh charging you get a 13 volt battery that then won't crank for jack.

You can jump with a car battery but NEVER jump with car RUNNING, the higher amp from a car alt will toast the bike parts.

 

[Greywolf43]

Well, after trying to bypass the solenoid and using the battery from my trailblazer (not running, of course) I got a rebuild kit for the starter motor, and after much contortion, got the part out without removing the carbs. The leaf switches (or whatever they're called) were worn down to nothing. Uopn replacement, the bike kicked right over. So, it turns out it was the starter motor (original factory part) that was the problem. Thanks for the insight, and I'm just glad I got it running just in time for rain.

On a side note, the bike has 184,539 miles on it, and that may have been the cause of wear. that's a LOT of starts. lol On the bright side, the replacement parts cost $30, so it didn't hit me too hard.

 

[amc49]

That is indeed a whopping number of miles, you are definitely in the top 5%. Most of them in hotter climates like here in Texas cook the chain tensioners to be going bad at 30K and chains then breaking from it by 50K. Most of the starters never get enough wear to break.

 

[Greywolf43]

I've been through a ton of chains. And tires. One engine top end rebuild around 100k miles. I did switch to a smaller thickness chain, and it lasts longer than the original. I just got an AGM battery to get rid of the lead acid. Now if monsoon season will just end.