Topic: Motogadget m-unit help!!!

[Carny cafe]

Hey everyone. I am looking for help with my current build. I am trying to install a motogadet m-unit on my 1975 honda cb550f. Right now I have brake, turn signals, and lights all working. I am trying to get the starter button and kill switch set up. Also I am running a dyna s ignition system in case this may change things. I know the solenoid works as I have connected positive and negative and it turns the crank, but set up with the bottom nothing happens. Ps. I know very little about wiring so treat me like a noob.

Thanks!

[calj737]

It's pretty easy really. Are you using the stock controls, or aftermarket? Which color wire from your controls do you on have running into the START input on the M-Unit?

[Carny cafe]

I am using the posh factory controls. A push bottom for the start and push button for the kill switch (the kill push button is a closed circuit that opened once bushed). I can make the wiring whatever colour really.

[calj737]

Have you run either wire from your control to the M-unit START input?

[Carny cafe]

I have the starter button wire leading to m-unit, and a second wire running to clean ground.
On the dyna s I have blue to blue, yellow to yellow, and red spliced into the black eom wires of the coils. Solenoid is confusing the hell out of me. Also don't no if I need the eom relay for the starter either. This is the point which I am lost.

[calj737]

You don't need the OEM relay with the M-Unit. Your start button from Posh is a momentary, push once, engine goes vroom. While engine is running, push it twice, engine goes sleepy. That's a built in function of huge m-unit.

The Yellow/Red wire to your solenoid now comes from the START output side of the M-Unit.

You should have your battery POS and NEG running a lead to the M-Unit as well. The BLACK from your key switch carries the switched 12v to the LOCK input. Also, into the LOCK input you want the 12v sensing wire from your Reg/Rec. This insures the Reg/Rec monitors the battery status and charges the bike properly.

You still need a direct to engine and frame bare metal ground from the battery NEG. I ran an inline 15a fuse between the Reg/Rec RED and the battery POS.


So to recap:
Key switch - BLACK to M-Unit LOCK
Reg/Rec - RED with 15a to battery POS
               12v sensing wire to LOCK
Posh Start - M-Unit START

M-Unit START output to YELLOW/RED of solenoid

If you have any other questions, I'll be back later this afternoon or evening.

[Carny cafe]

Hey cal. I am using a aftermarket rec/reg (oregan moto sohc version) my questions now based on what you have stated are the red and black wires from the rec/reg. the black should go the the brake and headlight correct? Where else would it go?

The red wire, does it go to lock output (aux)?

Also where does the black wire of the coils go into the m-unit?

Sorry for all the questions, but I figure others may have or will have the same.

Thanks!

[Carny cafe]

Oh! And any idea what to do with the red green wire from the solenoid?

[calj737]

Red wire from Reg/Rec should be to battery POS.
Black from Reg/Rec (I think on Oregon units) is the "12v sensing wire" which should go to LOCK with BLACK from Key switch.

The opposite of LOCK is AUX. You need to run 2 lines out of AUX, 1 going forward to provide power for the ignition coils, and for the gauge lights. The second line runs to the tail light as power.

Headlight power comes from LIGHT LO and LIGHT HI.

Tail light power comes from AUX as mentioned above.

Your coils don't wire into the M-Unit, you only supply power to them, from AUX.

RED/GREEN from solenoid wires to Clutch Safety Switch, and Emergency switch (Kill). You won't need either of these based upon your earlier email (you can double tap START button on Posh to "kill engine").

You can reach me directly if you want, I'm just chilling this evening.

[Carny cafe]

Thanks cal!

I'll try taking a run at it tomorrow after work to see if everything works out.

[Trad]

Cal, always so helpful. The best! 

[Carny cafe]

Cal, it all worked! Only thing I need to do is run a thicker gauge wire from the m-unit to the starter solenoid. Also, I had to ground out the green red wire. Other than that it was all perfect! Thank you so much buddy!

[calj737]

The YELLOW/RED from M-Unit START only needs to be 16AWG maximum. It's not carrying anything over 12v and pretty low amps, so don't go overboard else you won't get it to fit into the M-Unit port. I think 14AWG is about the maximum it will accept.

Glad it was so easy; those units are the bee's knees!

[Carny cafe]

It's the red wire gauge I need to increase. If anyone is looking at installing the posh factory control here is what I have learned. Used liquid electrical tape to seal the connections from wire to switch! Especially if the clipons or handle bars have a narrow inner diameter. Other than that it was straight forward thanks to cal. Just got to defuse the tank and then I can synch the carbs. And then I will post the full build.

Now that I have learned these few lessons it is actually amazing how simple the m-unit was to install! Anyone looking to upgrade electrical or upen up that triangular centre in their cafe I would highly recommend it!... Coming from a newb!

[calj737]

When you get a chance, solder that connection and cover in heat shrink for weather tightness. You'll be happy later that you did-

[Carny cafe]

I can see that being a great idea. Probably essential since I'm up in canada and the salt on the roads would probably give a beating to open electronic connections.

[calj737]

Beaten like a rented mule...

[Blackfin5]

Cal.  You need to hire yourself out as a m-unit consultant.  You have my biz!

[calj737]

The funny thing is, the unit itself is the easiest thing in the world. Once you know the couple of tricks on how to merge our vintage bikes with non-stock components into it, it's very, very easy. Trust me, I'm an electronics idiot but their stuff is idiot-proof.

[EricW]

Hi Cal,

Thanks again for the usefull infos and the time you have spend to explain it...

One more question  ...I own a Rick's Motorsport Regulator Rectifier and don't know how to plug it to the m-unit...any idea?

Eric

Honda CB 750 Four 1975
----------------------------------------------
Rick's Motorsport Regulator Rectifier
m-unit
m-button
m-switchs

[calj737]

Just sent you a PM too.

The loose black wire from RR goes to LOCK. If your RR came with a 6 wire plug, remove RED and install WHITE. RED then goes to battery POS. Loose GREEN is chasis ground.

[Blackfin5]

Cal, I'm sitting back enjoying this with an 18 yr Scotch in one hand and a Cohiba in another.  Cheers, Carny....kind of an inside joke.

[SOHC4 Cafe Racer Fan]

This last weekend was a cool Moto weekend at Ian Halcott's ranch near San Luis Obispo. Welding, wrenching, playing soccer pick-up games daily, riding twisties and consuming steaks, carne asada, Angels Envy Bourbon, Cazadores margaritas, Pacificos and moonshine!

[calj737]

Cal, I'm sitting back enjoying this with an 18 yr Scotch in one hand and a Cohiba in another.  Cheers, Carny....kind of an inside joke.

One of these days, I'm going to author up an FAQ written in English and drawn up for our CBs to help everyone out. I've been corresponding with Carny via email since he's in Pa-ree. I think he's pretty darn close as of our last exchange.

I just need a good, free, electronic drawing package to document the 3 different layouts: 750/550 stock controls with new R/R, 750/550 with m-button, and of course these with m-LOCK/aftermarket controls.

As you know, once you actually chat with someone who's set these things up before, they're pretty darn easy and slick.

[tbk125]

I apologize for bringing up a old post, but I just got a m-unit for my 78 cb550k. 

Starting with the key switch- I have 2 brown/white wires, a red and a black wire.  Black goes to lock? does red go to aux? Can I remove the 2 brown?

I am using the stock start button for the time being- the yellow/red goes to start out? What do I need to do with the green/red?