Topic: '76 Honda CB550F: Suggestions for Better Battery Life?

[Deltarider]

I was able to identify that the white field coil wire travels into the headlight bucket

Are you sure? White wire in the headlight bucket normally is the headlight low beam.

[magner]

I was able to identify that the white field coil wire travels into the headlight bucket

Are you sure? White wire in the headlight bucket normally is the headlight low beam.

It’s not literally a white wire, as most of the wires in the harness are blue wires that have been spliced into the original colored wires. I found the new blue wire that the white field coil wire was plugged into and traced it to there.

[TwoTired]

Is the battery in the headlight?

White wire to alternator, attaches from the vreg.  Is that unit in the headlight?

On the stock bike, battery, vreg., and alternator are far from headlight.

I'd have to assess your bike is wired by rank amature, and wouldn't trust much of it to be correct.  Small wonder your bike doesn't charge the battery.

Methinks you'll need to make a wire diagram accurate to your bike.

You need:
Three yellow wires from alternator to rectifier need connecting. Rectifier green and red (minus and plus) need to connect to battery minus and plus respectively.  This connects power from alternator output to battery input.

Next you need to control the alternator output strength.  This is done with the voltage regulator.  It needs power from the battery during run time, stock bikes provide this via the black wire ( switched battery POS) and green wire  (battery NEG). The vreg then needs a green and white connection to the alternator, green is normally handled by frame and engine connections, ultimately connected to battery NEG terminal.  The white wire is the control line from reg to alternator field. The reg sends power to the alternator, so the alternator can make power based on the battery voltage level.  Battery low condition sends full battery power, battery full condition and the white wire voltage is throttled back, which reduces alternator output, in order to keep the battery from frying.
Clearly the wires colors only matter from an human I.D. Point of view.  The internal copper inside the sleeve all looks the same to electrons, which are mostly color blind.

Your job is to ensure your bastardized bike wire connections conform to proper design function.  You will also need to find the voltage regulator and rectifier components.  The stock bike had these as separate units. "Modern" replacements may have combined these functions into one unit, with yet another color scheme for wire colors.  You still need these functions if you want the alternator to charge the battery.  Locate them on your bike or purchase one to make your bike distance rideable on the roadways limited only by your fuel supply.

Good luck!

[BomberMann650]

In case Magmar needs a visual aid.

Here's Mr. Weeks diagram for the OMP vvrem4-sohc.  Simplified, shows where things should go in order to work.

[magner]

Thanks that diagram is very helpful. Is it safe to just go ahead and order a new reg/rec unit? I don't want to waste money if it's not the issue, but it seems like the one on this bike sucks anyway. It only has 4 wires plugged into it; the 3 from the stator coil, and 1 red wire from the positive post on the starter solenoid. It is not getting any wires directly from the field coil like in the diagram. There is no reg unit in the headlight bucket so I have no idea why its the white field coil wire is going into there and then soldering into the 3 wires for the stock right handlebar controls.

[BomberMann650]

I will shamelessly plug the Oregon Motorcycle Parts reg/recs as the lifetime investments they are.

At some point, it might be smart to order and M-Unit too.  Get an actual set of color coded wires in place of mystery blue. 

[Gene]

just logging on to see how it turns out. I have a 20 mile each way commute in Los Angeles/Orange County - ride the bike almost every day - no problems. Has to be the wiring as has been discussed here. Since the PO cut everything up, including the electrical system, your problem is in there somewhere.

[Deltarider]

In case Magmar needs a visual aid.

Here's Mr. Weeks diagram for the OMP vvrem4-sohc.  Simplified, shows where things should go in order to work.

Mr. Week needs to have another look at it. He mixed up lo and hi beam as far as color wires, but that's a minor detail here. Actually that diagram is quite instructive in its clarity. Thanks for posting.

[bryanj]

The unit with 4 wires is only a rectifier the regulator must be somewhere else

[Gene]

There is no reg unit in the headlight bucket so I have no idea why its the white field coil wire is going into there and then soldering into the 3 wires for the stock right handlebar controls.

I don't know your bike but I had a 360 where the regulator was bolted onto the frame under the engine. worth a peek?

[scottly]

With a charged battery, turn on the key and note the voltage.

With the key turned lights on and reading from the posts on the battery i get 11.9V, and reading from the bullets on the 2 field coil wires I get 10.6V

Disconnect the two field coil bullets, and setting your meter to the lowest ohm scale, measure the resistance across the white and green wires: this is on the ends of the wires that go to the stator cover, not the harness.

[magner]

With a charged battery, turn on the key and note the voltage.

With the key turned lights on and reading from the posts on the battery i get 11.9V, and reading from the bullets on the 2 field coil wires I get 10.6V

Disconnect the two field coil bullets, and setting your meter to the lowest ohm scale, measure the resistance across the white and green wires: this is on the ends of the wires that go to the stator cover, not the harness.

I’m getting right around 4.1

[scottly]

With a charged battery, turn on the key and note the voltage.

With the key turned lights on and reading from the posts on the battery i get 11.9V, and reading from the bullets on the 2 field coil wires I get 10.6V

Disconnect the two field coil bullets, and setting your meter to the lowest ohm scale, measure the resistance across the white and green wires: this is on the ends of the wires that go to the stator cover, not the harness.

I’m getting right around 4.1

The voltage reading may mean that the PO wired the charging system for a shunt type regulator, which diverts any excess voltage to ground. The resistance reading is a bit low; it should be about 5 ohms on a 550, IIRC. By running a constant voltage to the field, instead of reducing the voltage to the field to limit the voltage, the field coil *may* have been over-heated, resulting in the 4.1 ohms?
Next test: first, with your meter set on the lowest ohms scale, touch the leads together and note the reading. Next, unplug the connector with 3 white wires, and measure the resistance between all three wires on the stator side of the connector: A-B, B-C, C-A.

[bryanj]

Difference in battery voltage and field wire voltage is too high meaning a high resistance joint somewhere.

[BomberMann650]

Difference in battery voltage and field wire voltage is too high meaning a high resistance joint somewhere.

OP's rectifier is toast and the PO's rewiring is suspect anyway.

[scottly]

Difference in battery voltage and field wire voltage is too high meaning a high resistance joint somewhere.

OP's rectifier is toast and the PO's rewiring is suspect anyway.

Bryan, this may be a matter of the battery voltage dropping between the time with the lights on at the battery, and then at the field. Not a smoking gun..
Bomber, we have yet to determine if the rectifier is toast; first we need to verify the stator wiring. If it checks out OK, the next test is the rectifier.

[scottly]

Thinking about taking it in to a professional...

You already have, in a way.

[bryanj]

A profesional would probably not touch a modified/hacked about wiring problem without returning it to standard.
If one would contemplate it look at 6-7 hours minimum at high labour rate PLUS whatever parts HE/SHE decides are necessary!

[BomberMann650]

Difference in battery voltage and field wire voltage is too high meaning a high resistance joint somewhere.

OP's rectifier is toast and the PO's rewiring is suspect anyway.

Bomber, we have yet to determine if the rectifier is toast; first we need to verify the stator wiring. If it checks out OK, the next test is the rectifier.

Daggummit I best be gettin back to da school house then.

Thought magner had already diode tested the thing...

[magner]

With a charged battery, turn on the key and note the voltage.

With the key turned lights on and reading from the posts on the battery i get 11.9V, and reading from the bullets on the 2 field coil wires I get 10.6V

Disconnect the two field coil bullets, and setting your meter to the lowest ohm scale, measure the resistance across the white and green wires: this is on the ends of the wires that go to the stator cover, not the harness.

I’m getting right around 4.1

Next test: first, with your meter set on the lowest ohms scale, touch the leads together and note the reading. Next, unplug the connector with 3 white wires, and measure the resistance between all three wires on the stator side of the connector: A-B, B-C, C-A.

I am out of town visiting family for about a week; but I tried to do this test already. I had a hard time getting a consistent reading from the multimeter as i had to jam the test lead into the plastic plug that held each of the 3 stator wires. If I recall correctly they were each between 2 and 4 ohms.

[beemerbum]

I suspect your charging system isn't working at all.

I would bet a little bit of money on this.

Considering he just swapped the PO's battery soon after acquisition.  Then drained the new one.  I'd hedge 3:1 odds.

SOHC Hondas are for fun, not practical motorcycling. Get a BMW (Bavarian Manure Wagon) and love the old Honda. Merry Christmas

[seanbarney41]

I suspect your charging system isn't working at all.

I would bet a little bit of money on this.

Considering he just swapped the PO's battery soon after acquisition.  Then drained the new one.  I'd hedge 3:1 odds.

SOHC Hondas are for fun, not practical motorcycling. Get a BMW (Bavarian Manure Wagon) and love the old Honda. Merry Christmas

Wut?...Sure sohc4s are fun, but they are totally practical as well.  I have ridden 100s of thousands of miles on sohc4s and never been stranded anywhere ever.

[dave500]

yeah ive put thousands and thousands of kays on these fours,without spending thousands and thousands of hard earned dollars!shove ya beemer up ya bum hole!

[TwoTired]

25 years of reliable commuting on Sohc4s say it is practical as well as fun.
But, a machine is only as good as its mechanic and reliable as well as its maintenance.

Didn't I read a mag article that said the machine was less remarkable than others (mostly brit bikes) because of its steadfast reliability. Few bikes back then could be driven off the showroom floor and on to coast to coast to coast to coast travel, with only routine tune up maintenance.  It was when unenlightened owners modified them when they didn't simply work at the push of a button.

But, those were the days where it wasn't mainstream fashion to make them racing only bikes, (by rank amatures) and then purpose them for street show bikes.  The ones that were modified so, didn't survive to be used today.  These became "parts bikes".

Cheers,

[seanbarney41]

25 years of reliable commuting on Sohc4s say it is practical as well as fun.
But, a machine is only as good as its mechanic and reliable as well as its maintenance.

Didn't I read a mag article that said the machine was less remarkable than others (mostly brit bikes) because of its steadfast reliability. Few bikes back then could be driven off the showroom floor and on to coast to coast to coast to coast travel, with only routine tune up maintenance.  It was when unenlightened owners modified them when they didn't simply work at the push of a button.

But, those were the days where it wasn't mainstream fashion to make them racing only bikes, (by rank amatures) and then purpose them for street show bikes.  The ones that were modified so, didn't survive to be used today.  These became "parts bikes".

Cheers,

thats a bunch of crap too    This is the bike that has gone the fastest, farthest, most dependablest (I know)
20180908_195337 by Sean Barney, on Flickr