Topic: 1978 CB750F ignition switch alternatives?

[Geeto67]

Has anybody re-wired their 1977-78 CB750F 5 pin ignition switches to use a different type of switch? I am changing out the top clamp and will no longer have a way to mount the stock switch, looking for something I can use in it's place, preferably something that can flush mount in a headlight bucket.

thoughts? options?

[bomorr]

Has anybody re-wired their 1977-78 CB750F 5 pin ignition switches to use a different type of switch? I am changing out the top clamp and will no longer have a way to mount the stock switch, looking for something I can use in it's place, preferably something that can flush mount in a headlight bucket.

thoughts? options?

If you have an abs plastic bucket you could always put a motogadget m-lock inside the headlight bucket. Thieves would be so confused.

https://revivalcycles.com/products/motogadget-m-lock-wireless-key

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[Geeto67]

Has anybody re-wired their 1977-78 CB750F 5 pin ignition switches to use a different type of switch? I am changing out the top clamp and will no longer have a way to mount the stock switch, looking for something I can use in it's place, preferably something that can flush mount in a headlight bucket.

thoughts? options?

If you have an abs plastic bucket you could always put a motogadget m-lock inside the headlight bucket. Thieves would be so confused.

https://revivalcycles.com/products/motogadget-m-lock-wireless-key

I have a fiberglass headlight bucket.

$160 RFID keyless lock system? um...no thanks. And it isn't because of the price (I'm sure it's a deal for the kind of tech it is), but it kind of misses the point of messing with old motorcycles.

[bomorr]

fair enough, to each their own. I personally love having a few misc. Tech Upgrades to update some of the old tech on these old bikes. But there is still something about having a truly clean stock bike from the 70's, the problem is I can never find one that some hipster hasn't chopped up and abandoned becuase daddy never taught them how to wrench.

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[Geeto67]

anybody have a real suggestion? Most universal iggy switches are either 2 pole or three pole and I guess I am trying to figure out how you wire something like a 3 pole switch in place of something that needs to take a 5.

Also, looking at the wiring diagram I see the ignition switch takes a ground off the rear stop light switch? is that right or am I reading it wrong:


I am thinking for any 3 pole switch I can combine the two leads that go to the taillight and the one that goes to the gauge lighting, right? any problems with load in combining them to one terminal? I would hate to have to replace switches regularly because I am exceeding the amp rating.


Anybody use a universal "marine" switch? I see a few of them are 5 terminal but one of the terminals is for a start function (like a car) which I don't plan on using. Something like this:
https://www.westmarine.com/buy/sierra--omc-ignition-switch--487751?recordNum=17

[Stev-o]

I used one of these in a K4 cafe a few years back...

http://www.autozone.com/batteries-starting-and-charging/ignition-switch/duralast-ignition-starter-switch/59504_0/?_requestid=3472477

[seanbarney41]

Geeto, I have done this.KIMG0022 by Sean Barney, on Flickr  This is on an F0.  I just used spares from an earlier k plus the Triple A mount I got at a swap for $1.  The earlier K switches seem to last much longer.  Then I scrounged up the correct sex block connector, cut and spliced the early k switch wires to fit, and plugged it into the F harness.

Sorry about the blurry pic and lack of detailed info.  Really bad case of the flu right now and Nyquil is seriously limiting brain activity.

The 750f model wiring is much more confusing than the early k's.  This bike needed more wiring mods to make it work with the parts that I had.  It took a long time to figure everything out.  I just isolated whatever part wasn't working until it was.

[Geeto67]

I used one of these in a K4 cafe a few years back...

http://www.autozone.com/batteries-starting-and-charging/ignition-switch/duralast-ignition-starter-switch/59504_0/?_requestid=3472477

that's pretty interesting - is there a wiring diagram for the different terminals?

[Geeto67]

Geeto, I have done this. This is on an F0.  I just used spares from an earlier k plus the Triple A mount I got at a swap for $1.  The earlier K switches seem to last much longer.  Then I scrounged up the correct sex block connector, cut and spliced the early k switch wires to fit, and plugged it into the F harness.

Sorry about the blurry pic and lack of detailed info.  Really bad case of the flu right now and Nyquil is seriously limiting brain activity.

The 750f model wiring is much more confusing than the early k's.  This bike needed more wiring mods to make it work with the parts that I had.  It took a long time to figure everything out.  I just isolated whatever part wasn't working until it was.

Was the stock early K switch a 4 terminal connector? or one of those round barrel do-hickeys? Either way they are still a 4-way switch. So did you combine one of the leads? or just leave it off all together? Looking at the K3-K7 wiring diagram it looks like the 4 block has all the same wiring except that extra lead for the taillight, so that gives me hope.

[seanbarney41]

Geeto, I have done this. This is on an F0.  I just used spares from an earlier k plus the Triple A mount I got at a swap for $1.  The earlier K switches seem to last much longer.  Then I scrounged up the correct sex block connector, cut and spliced the early k switch wires to fit, and plugged it into the F harness.

Sorry about the blurry pic and lack of detailed info.  Really bad case of the flu right now and Nyquil is seriously limiting brain activity.

The 750f model wiring is much more confusing than the early k's.  This bike needed more wiring mods to make it work with the parts that I had.  It took a long time to figure everything out.  I just isolated whatever part wasn't working until it was.

Was the stock early K switch a 4 terminal connector? or one of those round barrel do-hickeys? Either way they are still a 4-way switch. So did you combine one of the leads? or just leave it off all together? Looking at the K3-K7 wiring diagram it looks like the 4 block has all the same wiring except that extra lead for the taillight, so that gives me hope.

yeah, I can't quite remember.   Thinking something is slightly different different between F0 and F2/3.  I used wiring diagram from Clymer which looks quite different.  Pretty sure I did have to jumper something or left something unconnected.   One thing I see on the diagram you posted...the fifth wire is just to light the tail light in the switches 3rd position.  Does anybody ever really use that?  I sure don't.

[754]

Early were round brown type , then they went to white square connector.. Should be 4 or 5 wires.
 If it wont fit the bucket, you could try under the tank. Where Sean has his, easy to hotwire..

[Stev-o]

I used one of these in a K4 cafe a few years back...

http://www.autozone.com/batteries-starting-and-charging/ignition-switch/duralast-ignition-starter-switch/59504_0/?_requestid=3472477

that's pretty interesting - is there a wiring diagram for the different terminals?

Sorry, I dont remember but guessing yes.

[Jerry Rxman Griffin aka MuthaF'er]

One (only?) difference between early F and late F SWITCH SET is the early seat lock is spring loaded hinged key hole cover while the late F is not. I have one of each sets on each F0 bike. Both work fine.

As some one mentioned the extra position is for 'parking lights' which are not necessary. Why wouldn't an early (non 77/78) K model switch work for your application? Just cut off the plastic connector and mate it the switch.   

[SKTP]

I wired my 78K to work with the under the tank key....it was pretty easy. I just got both wiring diagrams (78 and 76) and followed them.

[scottly]

I am thinking for any 3 pole switch I can combine the two leads that go to the taillight and the one that goes to the gauge lighting, right? any problems with load in combining them to one terminal? I would hate to have to replace switches regularly because I am exceeding the amp rating.

Any single pole (two wire) switch will work, provided it has a 15 amp or greater capacity. Connect the red wire to one terminal, and the black wire to the other. The TL1 and TL2 wires are simply connected to each other. You can use a five or three wire type switch, but you will only use two of the terminals. Most automotive switches have 4 positions: off, accessory (radio, etc) ignition (run), and momentary start. If the accessory portion of the switch can handle 15 amps, you could wire the black wire to it, and turn the bike on in the first position, but if you use the ignition contacts, you will have to turn the key to the second position. 

[Geeto67]

I am thinking for any 3 pole switch I can combine the two leads that go to the taillight and the one that goes to the gauge lighting, right? any problems with load in combining them to one terminal? I would hate to have to replace switches regularly because I am exceeding the amp rating.

Any single pole (two wire) switch will work, provided it has a 15 amp or greater capacity. Connect the red wire to one terminal, and the black wire to the other. The TL1 and TL2 wires are simply connected to each other. You can use a five or three wire type switch, but you will only use two of the terminals. Most automotive switches have 4 positions: off, accessory (radio, etc) ignition (run), and momentary start. If the accessory portion of the switch can handle 15 amps, you could wire the black wire to it, and turn the bike on in the first position, but if you use the ignition contacts, you will have to turn the key to the second position. 

Ok, not sure I follow. I get that I connect the ignition and ground wires to the two poles, but connecting the gauge lights and the tail lights to each other? how does that get power to the systems? If I have an accessory terminal, couldn't I just connect them to it?

[scottly]

There are NO ground connections on the switch. The red wire supplies +12v via the main fuse to the switch, and when the switch is on, connects +12v to the black wire. The stock switch connects the brown/white wire at the TL1 terminal from the taillight fuse to the brown/red(?) wire at the TL2 terminal. When the stock switch is in the park position, the red wire is connected to the brown/red(?) taillight wire at the PA terminal, bypassing the taillight fuse, and turning the taillight on, but not the ignition or instrument lights. With a simple on-off switch and no parking light feature, the brown/white and brown/red(?) need to be connected to each other for the taillight to work, and still be protected by the taillight fuse.