Topic: CB500 Lazy Starter?

[sammermpc]

My '72 CB500 has been tough to start for a bit, now. I think it started after being out in a hard rain for an afternoon, but can't be sure.

This thread (http://forums.sohc4.net/index.php?topic=93775.0) describes it pretty well. Even with the battery topped-off (from a trickle charger), the starter will only turn around a couple've of times before grinding to a halt. Like it gradually runs outt've oomph and never quite gets up to speed to begin with. If I keep holding the starter, eventually it won't turn, and all just hear the little click of the starter solenoid (which I've cleaned up a bit, but not disassembled), as I keep tapping.

Anyhow, I'm new to bikes, and don't quite know where to start on this. I could take a look at the starter, but I am guessing I have a lot to do before getting there. I have checked all the electrical connections and cleaned them up and put some dielectric grease on, and the electric seems ok.

Background:
- Valves/cam adjusted (done it twice now, think it's right, but who knows?)
- Will start-up fine once hot, usually. Can kick it easily enough -- sometimes takes six or seven good kicks though.


When the engine's hot, starts no problem.

[dave500]

carefully try jumping it with another good battery when its cold.

[sammermpc]

Is there any way to check if a battery is good, otherwise? I'd have to buy another. Maybe I should as back-up, but I've got a multimeter, etc., and check the voltage regularly. It does seem like it drains faster than usual, but this is right off the tender when it's 13 - 12.7V.

[Icarus]

You could take your battery to an auto parts place and have them do a load test.  Its free.  Even a worn out/damaged battery can be charged up full but that doesn't mean it will produce the juice you need to crank the starter.

[Stev-o]

How old is the battery?  If you don't know or over two years, buy a new one.

[sammermpc]

Ok. Good to know. PO said it was "newish" but I should probably just pick-up another before diving into more complex stuff. Any recs?

[Stev-o]

I like the Scorpion, have a couple.  Sealed AGM, so no acid spills, $59 with free shipping...


http://www.batterystuff.com/powersports-batteries/sYT12C.html

[sammermpc]

Done and done, Stev-o. Thanks. I'll post updates -- though it's started snowing here...

[sammermpc]

Just a quick update -- I got the Scorpion you recommended, Stev-o. Dropped it in. And bang, started on the first go!

Since then, though, starts have been progressively slower, if that makes sense. Started right-off when new, now, a week in, it takes a couple more tries to get it going. I assume that means I've got to take a look through the charging system, as it isn't quite getting the battery where it needs to be.

Thanks for the help. I'll take a turn through the forums and see what wisdom on CB500 charging systems there is.

[Stev-o]

Well, glad to hear the first part, sorry 'bout the rest.

Do you have a multimeter?  If no, get one, something like this...



http://www.sears.com/craftsman-multimeter-digital-with-8-functions-and-20/p-03482141000P?sid=IDx01192011x000001&kpid=03482141000&kispla=03482141000P

Then you can check if your system is charging

[sammermpc]

Yah, I've got a multimeter -- I've never been clear what voltages I'm supposed to see, though, as my understanding is that it doesn't really get charging until it's 3k+.

I remember seeing a chart, maybe in the Clymer. I'll look it up. Is 12.32V normal? That seems lower than the readings I've been typically getting.

[Stev-o]

Ok, heres a simple quick check.

Check your battery volatge with the motor off, should be about 12.3, check.

Now, start the motor and and hold RPMs at about 3500 and check voltage.
Should be 14V plus. That shows it is charging.
At idle, these bikes really dont charge, and shouldnt be left to idle for long periods of time, 3-5 min max.