Topic: How do I adjust this???

[LoopsAndLogic]

Some of you know me as the 400f nut. Or at least, thats what my family calls me.
 My problem is, after installing a volt gauge on my bike, I noticed that my bike stays at 12.22v at idle, and when I hit 3200prm exactly, my bike charges a little over 15v. Which I know isn't good!!!

But as soon the bike revs over 3500+ rpm, it'll stay at 14-14.50 volts all day. Which is perfect

 I've never adjusted regulators before, but the Haynes manual gives me no input on how to adjust my regulator, except it tells me what needs adjusting.

I'm thinking my regulator is a solid state setup. Yeah??

  Any idea's on what to adjust and how to go about with this??  Could it be the rectifier??

At standing for over an hour, the battery will read 12.59 - 12.71 volts. Pending on the traffic I ride in.

Any help is appreciated
   
 L L

[mattcb350f]

Hi 400f nut! I recently found a PDF version of the original Honda service manual for the CB350 - 400 fours. the URL is: http://downloads.hondatech.info/Moto/CB350-400/CB350-400_06.pdf

this is #6 of 10 adobe files that make the whole manual. this one tells you how to adjust the voltage regulator.
 Hope this helps, Matt.

[drag0n]

It may not need adjustment  some of the older bikes were setup with alternators that didnt charge unless the bike was revving above 2000rpm or maybe that was 2500 i dont remember right off the top of my head but anyway you get the idea i would check around and see if yours has that type of charging system before i'd go trying to adjust  something that might not need adjustment

like my papaw taught me  "If it aint broke, dont fix it!"
Also "Just cause you can, don't mean you should!"

[eldar]

Well there are 2 adjustment points on the 750s. You have an "idle" and a high rpm.  I do not have the manual but I am sure some one does and can tell you what the gaps should be.

Not charging much at low rpm  is normal. Spiking to 15 or move, is not. I would almost bet the idle adjust is off but I do not know much about the 400s.

[jensk]

Well I have this jpeg with a page called Voltage regulator Adjustment. It is for the mechanical regulator on a CB550. I don't know if the CB400 is the same.
If  you need this you can find it at
http://www.kjellerup-hansen.dk/galleri/main.php?g2_view=core.DownloadItem&g2_itemId=224&g2_serialNumber=1
/jensk

[bryanj]

Firstly I would check the acuracy of the gauge with a DMM as most of the "aftermarket" gauges are moving iron slow reacting type

ALSO make sure it is disconnected when you turn the key off or it will draw enough to flatten your battery.

If it is ONLY at that exact revs easy -DONT DRIVE THERE as the other readings seem perfect

[LoopsAndLogic]

I did check with a digital meter and it corresponded precisely with the analog meter!!

What I don't get is, when I had the original headlight on, it charged perfectly at idle. Something like 12.55v.

Now with this dual setup, it charges at 12.22v. In each headlight is a 23watt bulb, and I'm only running one light on in the daytime.

The original is 35w low, and 50w high. Shouldn't I be gaining something here???

I used slotted connectors and 14 or 16 gauge wire for the new headlight setup. I'm wondering if something is wrong with this.......

I'm going to hook up my original headlight today with the new wiring and see what happens.

 Thanks for the links. Much appreciated!   I wonder if my soldering job has a poor connection somewhere

I did install aftermarket switches.

Looks like the regulator on the 400f is nonadjustable.

 I'll let you know what I find

LL

[eldar]

When you tested the voltage before, was the headlight in low or high mode?
In low you posted that it was 35 watts. So the other lights on low are almost 50 watts, so that could show your loss.

[LoopsAndLogic]

When I switch to High beams, the 2 headlights combined equal 46watts. Which is less than 50w.

I just went outside, and hooked up the leads from my meter to the low beam headlight and switched on the key.

The leads read 11.22v while my battery read at standing, 12.72v. Did I just find my problem???

I got the idea from TT to hook up one of my headlights to the key switch wire (yellow/black I think) so that I always have a light on, and when I switch to the high beam, the second comes on then. Thus both stay on.

His idea saved me a lot of time. Anyways, the light still goes off when I hit the starter so I know I hooked up everything correctly, but I think now I have a weak connection somewhere.

I'll wait further suggestions before proceeding.

Thanks 

 LL

[TwoTired]

I don't *think* you have a problem.

Batteries don't remain at a constant voltage while draining or charging.

At idle, the system load is about 100 Watts, while the alternator only makes about 40-50W.  So, the battery drains and the voltage goes lower.

Rev up the alternator and it makes more watts (about 150W).  What the bike doesn't consume is available to restore the battery.

Current only flows when there is a voltage potential difference.  If your battery is at 12V, you have to present a higher voltage for current to flow into it.

What's missing for the analysis, is just where you connected your voltmeter.  Is it connected straight to the battery?  Into the wiring harness?  You have permanently installed a test apparatus, and its connection points are relevant to its indication.

Wires and connectors have resistance.  In order to charge the battery, the output at the rectifier will be a slightly higher voltage than at the battery terminals.  The magnitude of this difference relates to the resistance between the two components.

Meter accuracy plays a part here as well.  A 5% error at the meter, equates to a .725 voltage reading error at 14.5V.  If it is reading 3% high at 14.5 volts, it will indicate 14.93 volts. What is your advertised meter accuracy?

If there is 0.5 ohm resistance between rectifier terminals and the battery terminals. There could be a voltage difference of about 2 V between the components depending on current flow.  This voltage differential diminishes as you get closer to the battery along the conductance path.  Where in the path is voltmeter connected?  Remember, the ground connection or 12V return is a path, too!

Battery voltage:
A lead acid six cell battery, full charged, should stabilize at about 12.6 V after two hours resting.
If a load is placed upon it, it will diminish in voltage, commensurate with the load size and time applied.
When charging, the voltage will rise commensurate with the potential applied over time duration.  A charging battery is considered full when it reaches about 14.5 volts.  Further power applied starts to separate the Oxygen an Hydrogen atoms from the sulfuric acid electrolyte solution (bubbles).  This causes a reduction in mass/ volume of the electrolyte solution and heating of the battery which also accelerates the electrolysis activity.
Immediately after charging current is discontinued, the charge potential surplus at the battery terminal will abate and should stabilize at about 12.6 v.

Hope this helps,

[LoopsAndLogic]

So your saying, when the alternator is only supplying 40-50W, and the load is 100w, which I checked and your correct (never questioned), it's draining 4.16 amps from the battery

  I connected my analog meter to the following:

 Negative = where the batteries negative wire is on the frame. I purchased a looped connector so it fits nicely.
 Positive = is on the side of the positive wire that connects to the solenoid.

  I installed a 3amp, 125vac switch from Radioshack in the positive line.

 I checked with my digital meter on these locations and they checked out precisely. I even get the same numbers from the battery all the way up to the top of the bike on every, as you would say "ground".

I just got back from an hour ride, and when I stopped my bike in the drive, I jumped off, ran to the tool box to grab the meter.....It wasn't there.... Spent 2 mins finding it, than ran back to check the readings from the batt.....

 It was reading exactly 13.13 volts. Is this good???

It's doing exactly the same thing that I described in my first post. Nothings changed.

 I'm pretty much convinced that there's nothing wrong as well TT. Unless anybody else has any input??

I'm going to go study the regulator on my bike, for when I understand exactly how it works, the better I'll be able to figure out if I can adjust it. If not, and I break it, I've got 4 more of these to mess with

Thank you
 
   LL