Topic: The Ever-Popular CB650 bad charging 'issue', formerly hot start 'issue'

[Frankenkit]

depends on what your regulator stops you at.  Mine tops out at 14.8ish too, but my honda oem one topped at 13.9.  Hey, Lee, try unplugging your rectifier and running the same test with the bike running and see how high it goes without the regulator.  Might want to disconnect the stator wires from the r/r too and tst them directly so you don't overload your battery.  electrosport said you can get up to 50v but expect something around 20-30 (at least higher than 14)

[leekellerking]

I dropped a line to Tony Weeks at www.Oregonmotorcycleparts.com to ask what voltage I should be getting. 

He is the one who built my Reg/Rec and should know, if anyone does.   


Lee

Yeah I can get 14 to 15 volts out of my charging circuit but my battery tends to lose water frequently so maybe I'm not the one you should go by.

[leekellerking]

Tony says I was measuring in the wrong place as the battery throws off the reading.  Reading at the red wire going into the solenoid, I get 14.8 at 5,000 rpm (give or take a few -- my teenager was holding the flashlight with one hand and twisting the throttle with the other).  That sounds better!

I dropped a line to Tony Weeks at www.Oregonmotorcycleparts.com to ask what voltage I should be getting. 

He is the one who built my Reg/Rec and should know, if anyone does.   


Lee

Yeah I can get 14 to 15 volts out of my charging circuit but my battery tends to lose water frequently so maybe I'm not the one you should go by.

[Frankenkit]

[Hush]

That's my normal (what is normal for these bikes?) reading too.

[leekellerking]

Hush, I don't think there is a "normal" for these bikes.   

Just "within tolerance" and "outside tolerance."

Anyways, I took a joy ride to the office (with some detours) and I'm satisfied it will get me there an back (all 56 miles) tomorrow.  Unless something else breaks.   

That's my normal (what is normal for these bikes?) reading too.

[Hush]

OK Lee, just watch your water levels now, mine need topping up every 2 weeks or so, not sure why but battery gives out 14.5-15 volts so maybe the regulator isn't happy.

[Frankenkit]

...what do you top up with, distilled water?

[TwoTired]

...what do you top up with, distilled water?

Yes, and nothing but...

[leekellerking]

OK Lee, just watch your water levels now, mine need topping up every 2 weeks or so, not sure why but battery gives out 14.5-15 volts so maybe the regulator isn't happy.

I will do that.  I got an e-mail back from Tony (technojock) and 14.5v at the red wire from the Reg/Rec is about right.

Lee

[leekellerking]

We're back!!!

Anybody know a good source of SOHC alternator brushes?  

Oh, yeah -- 1982 CB650SC.

[Frankenkit]

oooh. I wish I could remember where I got mine... ummm. try partsnmore or z1?

[leekellerking]

oooh. I wish I could remember where I got mine... ummm. try partsnmore or z1?

Regulatorrectifier.com seems to have the best deal -- $16.73 a set.  That's less than Bikebandit wants for one brush!

http://www.regulatorrectifier.com/catalog/Honda-CB650-CB-750-CB900-CB1000C-CB1100-Rotor-Brushes

Hopefully, I can order this Friday (pay day).

[Frankenkit]

try looking up the honda part number then looking at feebay.

[scottly]

Regulatorrectifier.com seems to have the best deal -- $16.73 a set.  That's less than Bikebandit wants for one brush!


Hopefully, I can order this Friday (pay day).

Geez, go to a shop that does motor repair; I got brushes for a Toyota Celica Alt, for like $4, and Toyota V-6 starter brushes(4 brushes) for $8. When I first ran into the rotor brush problem, with two CBXs, on the same day, in 1979, we went to a motor shop in Winnemucca, NV, and bought some brushes with pig-tails, filed them to fit the Honda brush-holders, and continued the trip....

[Frankenkit]

hmm... it may be back. Bike wouldn't start after being gassed up.  Sometimes it'd spin fast enough to fire up... but then it wouldn't.  

I gave it its obligatory 5-10 minutes (hard to really remember how much time passed when you're worried about being late for work) but it started again with a roar and we went home.

Whipped out the multimeter and tested the battery- 12.2v.   pretty low but I tried to start it probably more times than I should've without waiting...

The resistance at the black and white wires by the R/R was 12.6 ohms.  I'll check it again tonight when it's cold- but the actual rotor resistance should be 5.8.   I need to figure out where that extra 7ish ohms is coming from, since when I installed it, the b/w wire reading was within .1 ohms of the reading at the slipring, so there is something wrong here somewhere.

What a kick in the butt.

I need to either figure out wth is doing this, or carry a book with me so I can make it look like I'm sitting around, waiting on purpose.

[scottly]

Kit, how many miles since you replaced the brushes?

[Frankenkit]

maybe 500?

[scottly]

maybe 500?

 

[Frankenkit]

yeah.  Brushes, rotor and stator all replaced (rotor/stator rewound with new yellow, black and white wires) new regulator/rectifier.  New starter solenoid.  New battery.  All connections in headlight bucket cleaned and dielectric greased.  Ignition switch cleaned and dielectric greased. New (to this bike) and rebuilt starter motor. Right switch pod with run/stop/run and starter button cleaned, but not disassembled and cleaned the way the 350's was...  All LED idiot lights. stock wattage H4  headlight.

So. WTF is EFFING LEFT?!?!  

 

It seems like this happens to a lot of 650s.  that there is something designed very, very differently from the 550 and 750 (aside from the wholly different alternator) that could make this thing hard to turn over when hot?  Could it be a problem with a bearing or something in the bottom end that expands with heat and makes the engine hard to turn over? If this were so, though, wouldn't it a) seize after long rides, which it has never done, even after 5+ hours at 5-7k rpms, or b) NOT be good to go after only 5-10 minutes "rest"?
It doesn't even want to bump start when it does this stuff.  I've tried.  It only bump starts....



oh yeah. After 5-10 minutes have passed since its initial death.

[scottly]

Have you had a chance to check the resistance again? If it's still high, can you check at the slip rings.

[Frankenkit]

I was going to go do that right away when I got home.  If it's still high at the black and white wires, I'll test tomorrow sometime when I have more time and energy.

[Frankenkit]

sorry, Scottly, I just keep adding to my post above.

[scottly]

OK. BTW, the shop I have been getting brushes at is a small, mom & pop operation, that specializes in automotive, and when I first called about getting the Toy starter brushes, they told me, up front, to just bring in the old brushes and they would match them up. They didn't give a "fat rat's ass" (to quote my sister) what they came out of....

[Frankenkit]

resistance is now 25.4 ohms at black and white wires.  I'm pretty sleep deprived and since testing at the sliprings means removing the case guard and alt cover... it's gonna wait 'til tomorrow, after school.