honda305 Home honda305 Auctions honda305 Gallery honda305 Forum


honda305.com Forum

Login
□ Search
□ FAQ 
□ 
Vintage Honda Owners,
Restorers, Riders and
Admirers

My CB77 No Longer Charges the Battery

Charging System, Wiring, Lighting
Post Reply
mike in idaho
honda305.com Member
Posts: 411
Joined: Sun Jan 29, 2012 9:18 pm
Location: orofino, idaho

Post by mike in idaho » Sat Jun 14, 2014 9:12 am

sarals wrote:Here's the results of the test.

Brown wire, 4000 RPM - 6.01 volts
Yellow wire, 4000 RPM - 6.00 volts
Pink wire, 4000 RPM - 6.01 volts

Low. Something is apparently wrong with the stator coil. Or, the magnets are weak in the rotor. Either is not good.

The Podtronics apparently works fine.
Where did you connect the tester leads? Voltage numbers with one tester lead connected to ground don't mean much. Connect one test lead to the brown wire and the other one to pink or yellow.
'65 YG1
'65 CB160
'66 CL160
'66 CL77
'78 XS650
'79 GL1000
'69 T100R
'68 TR6
'69 T120
'72 750 Commando
my company car is a Kenworth

User avatar
sarals
honda305.com Member
Posts: 1014
Joined: Mon Jun 25, 2012 9:19 pm
Location: Monterey Peninsula, California

Post by sarals » Sat Jun 14, 2014 9:33 am

mike in idaho wrote:
sarals wrote:Here's the results of the test.

Brown wire, 4000 RPM - 6.01 volts
Yellow wire, 4000 RPM - 6.00 volts
Pink wire, 4000 RPM - 6.01 volts

Low. Something is apparently wrong with the stator coil. Or, the magnets are weak in the rotor. Either is not good.

The Podtronics apparently works fine.
Where did you connect the tester leads? Voltage numbers with one tester lead connected to ground don't mean much. Connect one test lead to the brown wire and the other one to pink or yellow.
Mike, that's how I did it. That's only way to check an AC circuit, you're can't reference ground and get an accurate reading.

Gentleman, thanks for the input!

48, I hear you. Absolutely.

Vince, Mike's still has one listed on Amazon. There's a NOS on eBay for the same price, too. Decisions.
1965 CB77 305 Super Hawk
1989 NT650 Hawk GT
1981 Yamaha XJ550 Seca

mike in idaho
honda305.com Member
Posts: 411
Joined: Sun Jan 29, 2012 9:18 pm
Location: orofino, idaho

Post by mike in idaho » Sat Jun 14, 2014 10:51 am

A magneto rebuilding shop may be able to recharge the magnets in the rotor.
'65 YG1
'65 CB160
'66 CL160
'66 CL77
'78 XS650
'79 GL1000
'69 T100R
'68 TR6
'69 T120
'72 750 Commando
my company car is a Kenworth

User avatar
sarals
honda305.com Member
Posts: 1014
Joined: Mon Jun 25, 2012 9:19 pm
Location: Monterey Peninsula, California

Post by sarals » Sat Jun 14, 2014 11:07 am

mike in idaho wrote:A magneto rebuilding shop may be able to recharge the magnets in the rotor.
That's a good point! I know of one, I'll give them a call - thanks, Mike!
1965 CB77 305 Super Hawk
1989 NT650 Hawk GT
1981 Yamaha XJ550 Seca

Vince Lupo
honda305.com Member
Posts: 1371
Joined: Wed May 04, 2005 7:17 am

Post by Vince Lupo » Sat Jun 14, 2014 1:52 pm

Don't know if these guys might be able to help, but maybe they can do permanent magnets: http://www.scooterwest.com/item_details ... izing/4045

Let us know what you find out!

User avatar
sarals
honda305.com Member
Posts: 1014
Joined: Mon Jun 25, 2012 9:19 pm
Location: Monterey Peninsula, California

Post by sarals » Sat Jun 14, 2014 6:52 pm

Vince Lupo wrote:Don't know if these guys might be able to help, but maybe they can do permanent magnets: http://www.scooterwest.com/item_details ... izing/4045

Let us know what you find out!
Vince, I just sent them an email. Thank you for that!
1965 CB77 305 Super Hawk
1989 NT650 Hawk GT
1981 Yamaha XJ550 Seca

redblk63
honda305.com Member
Posts: 104
Joined: Mon Oct 15, 2007 5:16 pm
Location: pasadena, california

Post by redblk63 » Wed Jun 18, 2014 5:19 pm

I'm with Mike on this one. I do not understand the following.
****
Here's the results of the test.

Brown wire, 4000 RPM - 6.01 volts
Yellow wire, 4000 RPM - 6.00 volts
Pink wire, 4000 RPM - 6.01 volts
****
Can you describe the measurement points you measure between?

I'd suggest the following.
1. Measure DC battery voltage across its terminals with engine OFF
2. Measure DC battery voltage across its terminals with engine at idle
3. Measure DC battery voltage across its terminals with engine at 4000 RPM
The important things are not the absolute values, but whether the voltage goes up when revved. The level it goes to will depend on battery condition and its state of charge.

If there is no Voltage increase above what was measured in steps 1 and 2 when revved, then it's time to look in to the alternator. In my 48 years of Honda experience, alternator failure is rare. In fact, I have never seen it. I have seen bullet connectors on the pink wire with a bad connection, so it charged with lights off but discharged when the lights are on.

I guess the next steps would be. (Someone else may have a better set of tests.)
4. Disconnect the pink, yellow, and brown wires from the alternator and measure AC voltage from brown to yellow at a few thousand RPM, probably could do the same at idle.
5. Repeat 4. between brown and pink.

Only if 4 and 5 show AC results below 12 V would I suspect the alternator. If 4 and 5 show AC results above 12 V (remember the AC reading is an RMS value, so peak values are 1.4 times greater) or so, I'd suspect bad connections or the "podtronics" thingie.

If you could post them, I'd love to see the values you get for those 5 measurements.
Cheers,
Larry - Pasadena (not an expert, but have done all repairs on my CB77s since 1966)

Post Reply




 

CB-77 | CYP-77 | Road Test | Riding Log | Literature | Zen | Marketplace | VJ Survey | Links | Home