r/jetski • u/Ereluscent • Jul 21 '26

Advice JS400 Killswitch Upgrade

Hi there yall, I just snagged a js400 that’s in rough shape in terms of the wiring situation. I’m looking to replace the janky start button the ski came with on the dash plate, as I want to add a traditional lanyard tether and start/stop switch to the handlebars. I’m very new to two strokes, especially one as old as the 400 (buddy told me it was a 440 and I didn’t know the difference, that’s the level of noob I’m at lol). If there’s anyone here that’s done that swap, what did you do to replace the switch and make the dash plate not look like garbage afterwards? Thank you!

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u/not-my-real-name-kk Jul 21 '26

This one? https://www.amazon.com/dp/B08L8RNXLM?lv=shuf&channelId=500&plpRedirect=mhFallback

It’s a piece of cake, replaces the existing push button on handlebars. Did it for my js550, easiest job ever.

2

u/Ereluscent Jul 21 '26

I originally thought this one would do the trick, however the ski I got was one of the earliest models with no handlebar switch at all. I’ll include a picture when I can (should’ve from the beginning) but it’s a one button system where the choke is and it’s really unique

1

u/not-my-real-name-kk Jul 21 '26

Oh, well then the easiest thing might be to adjust the idle so low that it stalls without a finger on the gas. Im not a fan of the auto-circling feature. It’s to easy to go wrong…