B2 alternator onto B1 wiring loom..how ???

I am restoring a B1 and have the engine out to work on. I want to put in a B2 engine now and need to convert the loom to take the B2 single phase alternator. Please can some one tell me the modification proceedure. The B2 has 3 yellow wires from the alternator. I need a combined reg/rec I guess??

like this ??

www.electrexworld.co.uk/rr60-regulator-rectifier-791-0.html

How do I connect it up to the B1 loom ?

All help appreciated.

thanks. :S

If I'm not mistaken the looms are the same. The connections from the stator connect to the reg and rec, which then all plugs into the main harness. I used a D model main harness on a B1 and, unless memory has failed me, I didn't have to alter that portion of the loom.

But it has been awhile...so I might be wrong on that.

timyoungman wrote:

I am restoring a B1 and have the engine out to work on. I want to put in a B2 engine now and need to convert the loom to take the B2 single phase alternator. Please can some one tell me the modification proceedure. The B2 has 3 yellow wires from the alternator. I need a combined reg/rec I guess??

like this ??

www.electrexworld.co.uk/rr60-regulator-rectifier-791-0.html

How do I connect it up to the B1 loom ?

All help appreciated.

thanks. :S

If we're talking about KZ650's then they are not the same. It would help to put the year and model in your signature. Going the way you are, it's much simpler than going the other way.

However, you said the "The B2 has 3 yellow wires from the alternator." Is that right? Then you don't have a B2 alternator. It should have two yellow wires.

Assuming you meant to say the B2 has 2 yellow wires, and you are using the electrex reg/rec you gave the link to:

Your B1 loom has 3 yellow wires from the stator. You simply take two of them and connect them to the new stator. Leave the third yellow unconnected. Then put the 1-phase rec/reg where the old rectifier connected, using the wires that went to the old rectifier. You will be using the other ends of the two yellows (leaving the third unconnected) to connect to the two yellows on the reg/rec.

The wires that went to the field coil can be left unconnected. The wires that went to the old regulator should be unconnected, but taped off because the brown will have switched 12v on it.

I wrote this for the Kz1000/Kz1100's but it should apply for your bike too:

The regulator/rectifier plug on the 80’s bikes usually has six wires in it:

A. One (1)WHITE with RED stripe, this is the bikes main power wire usually 12 gauge in size.

B. One(1) smaller Brown wire, probably 18 gauge or so, the voltage sense wire for the regulator/rectifier, helps keeping it from overcharging the battery.

C. One(1) BLACK with YELLOW stripe wire, part of the ground circuits(Earth), maybe 16 gauge in size.

D. Three(3) YELLOW wires, maybe 14 gauge in size, the alternator output wires going to the regulator/rectifier which converts the Alternating Current(A.C.) to Direct Current(D.C.) using rectification, producing the power to run the motorcycle and charge the battery.

Reinstall the sprocket cover, again checking for pinched wires before tightening. Install the shifter on it’s splined shaft checking for proper location, and the left side foot peg assembly.

Except for the minor oil spill and reluctant fasteners, it’s not a very difficult job to do.

MFolks wrote:

I wrote this for the Kz1000/Kz1100's but it should apply for your bike too:

The regulator/rectifier plug on the 80’s bikes usually has six wires in it:

The '78 to about '80 kz650's used 4-wire, 1-phase reg/recs.

so it's just 2 ac leads, one positive output, and one ground.

Gents, sorry i'm still a bit confused. Here's some more info.

My currenr alternator has 4 wires coming out of it. 3 yellow to the rectifier. 1 green to the regulator.

The current regulator also has a brown wire running from it to the flasher unit and a black/yellow earth wire runnnig to earth.

The Replacement alternator has 3 yellow wires coming from it . no green earth wire or any other wires.

Questions.

What type of combined rec/reg do I fit to this alternator

Where do I connect the brown and black/yellow wires when the old regulator becomes redundant ?

Thanks.

Tim

Still need confirmation on what bike we are talking about.

If it's a 650, you said you were replacing the motor. Then the old alternator is irrelevant, correct?

The new alternator is totally different from the old alternator.

The wiring is different as described above.
In your swap you will no longer need the green wire to the old alternator. If you get a reg/rec combo for a 78 KZ650, and there is no brown wire on it, then you leave the brown wire unconnected and taped up.

timyoungman wrote:

The replacement alternator has 3 yellow wires coming from it .

As Lou said, the B2 shold have a 1-phase alternator (2 yellow wires). Before spending any money on a reg/rec, make sure you're not confusing the wire for the neutral switch with a stator wire - the neutral switch wire joins the stator wires under the sprocket cover, travels along with them and joins the same plug.

The easiest way to determine what you actually have on the B2 engine is to pull the stator cover and look at the stator - if it has 12 poles it's a 1-phase and you'll need a 1-phase reg/rec, if it has 18 poles it's a 3-phase and you'll need a 3-phase reg-rec.