The Silent Killer (Switch)

[mizadventure]

oops, I meant -- I can still get the bike home (or at least to my friend-w/-the-lift's garage, which, I'm starting to suspect is it's "real" home).

[pamcopete]

Here is a wiring diagram of the mods for mizadventure.



In addition to adding the ignition relay to bypass the troublesome key switch and kill switch, she installed a VR291 solid state voltage regulator powered from the relay contacts to ensure that the regulator was "looking at" the battery voltage and not the load voltage. She also arranged the two fuse holders so she could connect the fuse holder from the relay contact (87) that powers the coils to the fuse holder from the battery (red wire) so if the main fuse blows, she can disconnect the regulator and "cross" the fuse holders so the coils get power.

[pamcopete]

lupillus

Well, if you do these changes with the red wire and brown wire at the ign switch, then you shouldn't have to change any other wiring. All you are really doing is cutting the brown wire and connecting the load side to one contact of the relay. The brown wire from the switch goes to the coil. The red wire stays where it is connected to the switch....you just splice another wire to the red wire at the switch and connect it to the other contact. All of the load connections stay where they are.

[sgtsteve]

Miz,
Can you repeat/go over what you did with that relay? Where?
Sgt Steve

[xcbullet]

A big thank you to pamcopete,I finally did the relay,Put it off as I don't like messing with electrical,but with the schematic you gave I got it done.At first I tried to T into the coils but it back feed the switch once on it wouldn't shut off.Then thought Id take away the power going to the coils at the fuse,but then starter didn't work,schematic in manual showed it only going to coils ,but from what I seen there was other things that weren't so in the clymers,so tied that back together with the wire nut.once done had twice the volts that I could get at best before.Also in pic I made a small jumper so if the old wiring fails to even turn on relay I can unplug relay & jump the wires going to relay ,that's one of the reasons I put it under the seat.In the pic the two red wires look like there in the same spot but the one on bottom goes to the ground on battery.Tank of gas ran like this & all is good.
update10/26/08 had to get power to turn on relay at coils (old wires)instead of at the fuse so that the kill switch would work.

[detroitmuscle07]

I just did the relay install, but I'm waiting on petcocks so I wasn't able to ride it yet. The voltage change was only .1 volts at the coil now instead of .5 volts before. That seems like it's working properly to me. I'll post back when I can get the gas tank back together.

[pamcopete]

Here is a repeat of the original relay bypass circuit as posted on page 2. The other wiring diagrams on this page are alternatives:

[pamcopete]

xcbullet and detroitmuscle

Glad it all worked out for you. The relay mod takes care of one of the most common problems in the XS wiring and the cheap brass contacts in the ignition switch and kill switch. It's like getting a new ignition switch with precious metal contacts for $5!!

[onebadchop]

I know that i am about a page behind on this discussion, but I have an 83 heritage, made into a bobber. I retained the factory throttle and use the key to kill the ignition. I am now using the throttle side kill switch for my high/low beam selector. Works pretty good.

[CaptDan]

Gents,
It seems the relay upgrade would be even more beneficial on a bike that does not have a battery, where electrical current for the coils comes straight from the alternator via a capacitor, yes?

[pumps]

I just have two comments. About the kill switch. When I was laying on the ground with a 79 KZ650SR on top of me I was trying to keep the weight off of my right leg and didn't want to take my hands off the bars to use the ignition switch to shut the bike off. The kill switch was right there at my finger tip enabling me to shut the bike off.
About the relay mod. Did it to the aforementioned KZ650SR and it worked like a champ. I used the info gleaned from a fellow KZ enthusiast's website from kzrider.com . www.wgcarbs.com/index.php?option=com_content&task=view&id=12&Itemid=26

Hope this helps someone.

[pamcopete]

pumps,

Well, actually, it is not a good idea to switch off the ignition when laying under a motorcycle with gas running down your back unless the engine is running. Generally, most ignition systems will produce a spark when you open the circuit with the kill switch.

Better to just let the battery die slowly and not cause a spark, but it's hard to overcome one's natural instincts.

[10ecjed]

I will clean my switch again this winter. I like the kill switch for two reasons. First when I put the bike in the garage at night there is no easy way to turn on my garage light. Just hit the kill switch, put down the kick stand and then go turn on the light.
Secong comes from dirt bike riding. Once I crashed pretty bad off a large jump in the sand. Landed face first. OUCH!! That hurt. The throttle stuck in the sand with the bike full throttle. No kill switch. It was spinning around in this sand and gravel pit and here I am hopping around trying to catch the darn thing by the clutch. Finally I got it, stood the bike up jammed it in first and let go the clutch. Darn thing took off down the track without me, fell over and started doing it again. Luckily it died and I sat down and cried. WOW that hurt. Next day I was at the shop buying a kill switch.
I do not plan on jumping this bike in any gravel pits so this will probably not happen on the 650. But you never know.
Gotta love that kill switch.

[feliz]

I checked mine today and I have a 1.2 volt drop across the switch........ouch. Is it difficult to disassemble and clean the switch, never done it?

[pamcopete]

feliz,

It's not difficult. Just a couple of screws, but there is a tiny, tiny, tiny spring loaded ball bearing that holds the contacts closed and it will spring out and blast across the garage never to be seen again if you are not careful.

I suggest putting the switch in a clear plastic bag as you remove the screws to contain the tiny, tiny, tiny ball bearing.