Kill Switch

Have searched the site for kill switch issues on MKIII, but still have a question. My kill switch sometimes goes on the blink. I don't (knowingly) move the switch, yet the bike refuses to try to crank sometimes. I can move the switch back and forth with no results. So far, if I move the switch and forth and turn the ignition on and off, it will start. I don't think the switch is replaceable, is it? If not, I suppose I could bypass the switch. However, even though I have never needed to use a kill switch for an emergency, the option is nice to have. I have considered replacing the whole piece that contains the switch as it would be a good thing cosmetically, but don't know what to call the piece or if it is available, or where. Any help would be appreciated.

Though many of us have opted to bypass (remove) the kill switch circuit altogether (the lucas switch itself is the weak link), I can understand the desire to have that option readily available. My suggestion is to get yourself a simple, modern push button switch and wire the ignition (white lead) through that:

http://www.ebay.ca/itm/Universal-7-8-Ha ... gE&vxp=mtr

ElTigre1 said:

I don't think the switch is replaceable, is it?

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There's often no need because the kill switch itself is relatively simple so isn't difficult to repair.

A nylon slider containing a small spring-loaded brass plate bridges two contacts when the switch is moved to the ON position. All it may need is the contact surfaces cleaning with fine abrasive paper, however, the small multi-pin 'Amp' plugs can also cause similar problems so should be cleaned and if necessary cut off and replaced with bullet connectors.

All disk brake models are susceptible to corroding kill switch from leaking master cylinder. I have seen less issues with stock master cylinders that have been sleeved.

If the MKIII only had disk brakes and the kill/cutoff was only an ES related item, why would any other model than a MKIII have this issue.

Sorry, just in the mood.

pete.v said:

If the MKIII only had disk brakes and the kill/cutoff was only an ES related item, why would any other model than a MKIII have this issue.

Sorry, just in the mood.

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Because the MkIII switchgear causes the extra leaks.

In 45 years of ridding bikes, with kill switches I have never used them, even in emergencies never had to use them I think they are a wasted part that can cause more problems than what they are worth, one thing that does get up my so and so is when people turn my kill switch to the off position with out me knowing about and wonder why my bike won't start, I got rid of the kill switch on my Norton over 35 years ago, but my Triumph Thruxton has one and have been caught out a few times with people touching things they shouldn't.

Ashley

If in 45 years of riding bikes you have never used a kill switch I can only assume you have never followed your bike down the road / grass trying to switch off the motor before it revs its nuts off and goes bang!!
I learnt VERY early on that an old Lucas car pull for on and push for off switch fitted to the top of your headlamp shell that you can easily find and thump was rather handy especially when following ones Dommy down the road after striking a patch of oil or when on following ones bike down the grass for example when exiting Windy Corner one late September day in front of the highly amused Manx Highway Board gang digging the hole for the cattle grid that replaced the VERY famous gate with its 'Please Close the gate and keep the wind out' or something similar notice!! I have always wondered which Laxey pub that notice ended up in. I was so distracted at finding humans up there and wondering 'what the hell are they doing' I totally missed the painted peel off point post and having spent TT practice sessions at Windy and watched riders bouncing along betweeen their bike and dry stone wall as they all heading towards the 33rd and running into the ditch that runs along side it i bailed out laying the bike down BEFORE hitting that ditch! I had a fag on the go before they reached me ....... It was also handy when bombing down a hill with a junction at the bottom when the carb slides would not close having frozen fully open!! But I was young in those days and thanks to fitting those switches lived to become very olde and annoying, as the wife and others keep on telling me but one has to have a purpose in this life!

Sorry .... I am with Ashman .... those kill switches can be a real pain when someone else fiddles with it ..... no switch on my Commando .... and if it was easy I would take the kill switch off the other bike too .... key is easier in a pinch anyway ...
Craig

I have been down the road many a times in the dirt as well as the road on dirt bikes as well as road bikes, most of the time on the left side of the bike, have also been trapped under the bikes as well, when trapped under your left side of the bike try and reach the kill switch that is on the right side of the handle bars, impossible to reach, lucky motors not reving its guts out, I have never had problems with turning the ignition switch off or letting the motor conk out, most of the time when things happen so quickly you don't even think about kill switches or turning your motor off, it's a bit hard when sliding down the road on your arse trying to avoid other cars or your own bike for that matter, the first thing that come natural is to save your own arse before your bike.

Ashley

While looking for high resistance connections on my MKIII the only thing I found reliable with negligible voltage drop was the ignition switch itself. All the connections and the kill switch had excessive drop. Cleaning them did improve things but the kill switch was still so-so. My bike has a direct connection from the battery through an ATO fuse assembly to the ignition switch to the Pazon. I've been riding for 50 years and never needed a kill switch so I'll take my chances.

pete.v said:

If the MKIII only had disk brakes and the kill/cutoff was only an ES related item, why would any other model than a MKIII have this issue.

Sorry, just in the mood.

Click to expand...

Obviously the MkIII is not the only model with disc brakes and not the only model with a kill button and not the only model with corrosion issues in the right side switchgear (which contains the kill button/switch). Water collects in neglected Norton/Lockheed cylinder bores and will cause pitting and leaks. Honing will often not remove this pitting and the master cylinder will leak with new seals. Sleeving not only improves braking, but eliminates the pitting of the aluminum bore.

Ron L said:

pete.v said:

If the MKIII only had disk brakes and the kill/cutoff was only an ES related item, why would any other model than a MKIII have this issue.

Sorry, just in the mood.

Click to expand...

Obviously the MkIII is not the only model with disc brakes and not the only model with a kill button and not the only model with corrosion issues in the right side switchgear (which contains the kill button/switch). Water collects in neglected Norton/Lockheed cylinder bores and will cause pitting and leaks. Honing will often not remove this pitting and the master cylinder will leak with new seals. Sleeving not only improves braking, but eliminates the pitting of the aluminum bore.

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Are you sure about that? Show me any Norton schematic that offers the "cutoff" other than the MKIII.

pete.v said:

Ron L said:

pete.v said:

If the MKIII only had disk brakes and the kill/cutoff was only an ES related item, why would any other model than a MKIII have this issue.

Sorry, just in the mood.

Click to expand...

Obviously the MkIII is not the only model with disc brakes and not the only model with a kill button and not the only model with corrosion issues in the right side switchgear (which contains the kill button/switch). Water collects in neglected Norton/Lockheed cylinder bores and will cause pitting and leaks. Honing will often not remove this pitting and the master cylinder will leak with new seals. Sleeving not only improves braking, but eliminates the pitting of the aluminum bore.

Click to expand...

Are you sure about that? Show me any Norton schematic that offers the "cutoff" other than the MKIII.

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All Commandos from 1971 had a kill switch (push button, pre-Mk3) although not always on the right-hand side cluster, and it's shown on all '71-on wiring diagrams.

Ok, I'll stand corrected AGAIN, LAB. Would that be WY?
J19

pete.v said:

Would that be WY?

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Yes.

Thanks, all. I have cleaned things up, but I seem to be having trouble with the detent, so I will probably have to bypass the switch. Not quite sure how to do that, but I have a local British bike guru, so will try to put it in his hands. Will that involve anything external? Thanks.

ElTigre1 said:

Thanks, all. I have cleaned things up, but I seem to be having trouble with the detent, so I will probably have to bypass the switch. Not quite sure how to do that, but I have a local British bike guru, so will try to put it in his hands. Will that involve anything external?

Click to expand...

Just connect white/yellow to white at the switch cluster's harness connection.