Charging

[Fairview]

Hi, I have a CB550/4 k1 which is in unrestored condition but running nicely. I've ironed out a few problems over the summer including an irritating oil leak. The trouble I have now is a lack of charge, it's been like this since I had it but is going to be an issue with the shorter days now as I need the lights.

If there was a class for Motorcycle Electics I'd definitely be in 'Remedial' so I'm not anticipating an easy fix for this. I've looked through the manual and other posts but am still not clear on any of it. The battery seems to hold its charge when the bike is doing nothing and will seemingly charge on long fast motorway runs. Normal day to day stuff and it completely discharges.

If anyone here could give me a step by step diagnosis to start with that would be great and if you can avoid talking about flux capacitors and so on that would be even better. Thank you.

[SteveD CB500K0]

First step is to measure the battery voltage, across the terminal with a digital voltmeter:
1. Ignition off
2. Ignition on, lights off
3. Tickover, lights off
4. 3000+ revs, lights off
5. 3000+ revs, lights on

Post results here

Steve

[matthewmosse]

Off the face of it I had a similar issue and eventually found that it was only charging from 2 of the 3 coils on the altinator (first check might be to just clean and inspect the contacts on the 3 yellow wires. The long motorway speed retaining charge factor leads me to think you have a similar issue - On a couple of occasions I had to complete the last 20 miles of b road riding in the dark and only switching my lights on when I could see approaching headlights either ahead or in the mirrors and relying on moonlight the rest of the time. I had to keep the revs up to even keep her running. I was really glad when I swapped the altinator for a good one but I now know one of my spares is the dud but not which one! doh!

[Bryanj]

One of the problems with these is that with lights on and if everything is working they do not charge till over 3,000-3,500 revs.

The alternator itself is normally very robust and only fails due to mechanical (accident or ham fistedness) rather than Burn out.

The most common problem is a bad connector somewhere but you need to get a decent multimeter and be reasonably proficient with it to sort it out

[Ewan 500 K1]

One of the problems with these is that with lights on and if everything is working they do not charge till over 3,000-3,500 revs.

The alternator itself is normally very robust and only fails due to mechanical (accident or ham fistedness) rather than Burn out.

The most common problem is a bad connector somewhere but you need to get a decent multimeter and be reasonably proficient with it to sort it out

I'm conusticated ... why does the clymer manual say that "nightime" charging current v's revs is;
 1000revs = 2-3  amps
2000 revs and all revs above that  = 1 amp

[Ewan 500 K1]

see "charging system test" page 124 -129 clymer 350-550cc fours manual. I followed that and found that the stator coil was duff. Replaced stator with one that tested kay and everything been fine since

[Bryanj]

The confused part is all explained by the word Clymer mate

[Yoshi823]

A suspicious alternator stator is quite easy to test.With a multimeter set to ac volts measure across any two yellow wires & you should measure about 25vac. If you were only getting about half that or none at all from that pair it would be easy to check across an adjacent pair of yellow wire & to isolate exactly which winding was open circuit. As the standard bikes have a seperate rectifier to the regulator these are also easy to test.

I have come across corroded points inside of the OEM regulator case in the past. Just polish these up with a points file & they're good to go. The points gaps are specified in the manuals. I do a final setup using a voltage supply with a multimeter hooked up to the output. The adjusting screw which sets the regulated output voltage is then easily set. 

[Ewan 500 K1]

The confused part is all explained by the word Clymer mate

  you mean Clymer talk S**T ?   

Haynes quotes similar alernator out v's revs for "nighttime " running of a 400/4 ... but does not that there is zero alternator output until 3000rpm under "daytime" conditions. Clymer for daytime claim 6.5amps at 1000rpm "daytime" , dropping to zero amps at 2000rpm , then picking up again at 3000rpm

[SteveD CB500K0]

That's probably a typo...

Glenn has the numbers here: http://www.sohc4.net/index.php/chargingsystem-2/

[Ewan 500 K1]

That's probably a typo...

Glenn has the numbers here: http://www.sohc4.net/index.php/chargingsystem-2/

cheers for , that ..right handy. Anyone got the same for 500/4's ?

[SteveD CB500K0]

Pretty similar I'd have thought.




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[LesterPiglet]

The confused part is all explained by the word Clymer mate

Love it.   

[Fairview]

Thanks for the replies everyone.

Steve, this is the sort of step by step idiot guide I was hoping for, so here are the figures

1. 12V
2. 11.25V
3. 11.60V (fluctuating)
4. 11.78V (fluctuating)
5. 12.26V (fluctuating)

Incidently, when the battery gets low if I turn the lights on at tickover the bike looses ignition and stops running and all the console lights go out. A press of the starter button seems to get them back and then it will start on the kick, I'm not sure if this a related fault or not.........

Thanks again.

Tristan

[hairygit]

If pressing the starter gets it back, check your earth cable to frame connection from the battery