125mh kill switch help

[Roskowski30h]

This past weekend we were testing the 125mh and near the end of the day had a kill switch go out on us. Verified the kill switch was actually the problem by jumping the kill switch lead on the motor back to itself. I ran this same kill switch all last season with no problems.

We've heard that other people had experienced similar failures with the regular kill switches and that there had been some success changing to a different model/style switch. Do we need to run a switch with a higher current tolerance? Better contacts? Different style switch all together?

[T Chance]

Is this the dual purpose switch where it can be hooked up to either make or break a circuit? I find they are poorly made and it is best to install a new one every year.

[Roskowski30h]

That is the type of switch we had fail in the boat. I've had little to no problems with those types of switches before so long as they were dried out after being submerged. Is there a higher quality switch available, all the marine kill switches I see are typically some variant on that design? I'd hate to just gamble that the kill switch works and have it die part way through a heat

[dwhitford]

I have made dead-reliable kill switches from spring-loaded plastic snap-bag clips from the Dollar Store. I epoxied a strip of metal to each inside face of the clip and drilled thru each clip face and its metal strip so that I could go thru the hole with a 10-24 little nut and bolt to hold on a wire (back to the engine) from each clip face. I hold this clamp open with a wooden dowel cross-drilled for the lanyard that attaches to my life jacket. When the dowel pulls loose from the snack-bag clip, the two metal strips make contact and ground the ignition.

This is so simple that there is nothing that can go wrong short of utter destruction of the snack-bag clip.

[bmitch1]

We use the Mercury Racing kill switches on our 125 mods....I think the internals are a little heavier. I also had issues running the cheaper clip styles.


See Mercury part # 525-368100


https://www.cpperformance.com/p-1446...ignitions.aspx

[mercguy]

I only use the Mercury kill switches....they never fail and can be used either normally open or normally closed....

p/n 856654A4 comes with a 20ft harness...……...is the 3 wire switch that can do either ignition system (mag or CD)...

[bmitch1]

One clarification for anyone shopping for switches - the electronic ignition on the PRD Fireball requires Mercury part # 525-368100 to disconnect the power from the ignition when the kill switch is pulled.

We use the Mercury kill switches on our other Merc, OMC, SW engines that are magneto-based and that requires Mercury part # 525-368101 to ground the ignition when the kill switch is pulled.

If you have a cool trick to use one switch for both functions then I owe you some drinks this summer!

[dwhitford]

Bmitch, I adapted my snack-bag clip switch to kill the magneto Motoplat CDI, requiring 3 wires to kill it, on my 250 Quincy engine. (I like Yeungling Black& Tan, incidentally)

[mercguy]

We use the Mercury Racing kill switches on our 125 mods....I think the internals are a little heavier. I also had issues running the cheaper clip styles.


See Mercury part # 525-368100


https://www.cpperformance.com/p-1446...ignitions.aspx

that switch is for "normally closed" ignitions only Brian...……. the actual Merc p/n is 856654a2...….get the other switch and you can do both style ignitions ……...I do it in my boats when I either run a battery ignition or points style ignition...….