Do most of you guys run kill switches on your shifter karts? From past experience tuning outboard engines with programmable ECMs we would always run the boat to the desired rpm and kill the motor then read the plug and the top of the piston with a bore scope. It seems that it would be impossible to get accurate plug readings on the kart without the kill switch. How do you guys do it?
Most do not, the vibration on a kart could possibly kill the kill switch, and if it dies shorted out, you stop. It may be a very overstated issue, I had one installed for a while and it never hiccuped.
I have one on mine, and used them on Formula 500 cars for years as well (similar vibration), and they work fine. The only issue I had once on an F500 was that I used a toggle switch, and after hitting a curb particularly hard one time, the switch switched itself. I then upgraded to a “firmer” switch (the old one was particularly bad with a rather large toggle arm), and have never had an issue. On the kart I’m actually using an OE Honda part, which is just nicer since it has the correct connector on the end.
That said, I hardly ever use it on the kart. My only real reason for having it is so I can kill the engine in the event of a chain break.
I installed one on mine after a couple of the guys I road race with told me that they were doing exactly as you stated above. At race’s end, they’d stay on the throttle during the ‘cool down’ lap, and as they approached the pit lane entrance, they’d kill the power and coast to the scales. Then they could get a good read on the plug. I’ve hardly ever used mine, but it’s there, and I haven’t had any issues with it. I now have a starter button located next to it, as I have installed a Hegar 4 starter on my Stock Honda.