Kawasaki Jet-Ski 440/650 Conversion. RIPPER! (Motor swap)

I drop a 1993 650cc engine out of a Super Chicken. Into a JS440/550 hull. 440 electronics with a 650 voltage regulator. Stock waterbox. Stock 440 impeller. The ski has a lot more power! It does however, have some cavitation when throttle is punched. Needs a bigger impeller. Im going to try a 19 pitch. For now though.. It works great. Usable! Yanks my 200 pound butt out of the water! Please hit "like". It helps big time! Cheers!

[@doublem6027]

Great to see people are still doing content on these ol skis . 🤙

[@StefanMailey]

Thanks brother!! Appreciate you!

[@billythephoenix]

Wow! It ran well. Good job on the ski and the detailed video/edit 👍

[@StefanMailey]

Thanks soo much! Appreciate your kind words. Im posting a new video tomorrow. I race my 9yr old daughter on her VXR 701cc ski. Im hoping the video ok.lol. Thanks again!

[@billythephoenix]

@@StefanMailey 👍

[@JoelArseneaultYouTube]

I buy Spray 9 by the gallon... Love it, haha. Great job on the build. I thought I heard a dead spot... wonder if it's carburation or if the extended exhaust isn't tuned at that RPM... A longer head pipe will raise the power band up a little. Sounds like it runs great once it's revving. Good job on the ediinging... and your own music.. Impressive.

[@StefanMailey]

I’m waiting in a carb kit. The diaphragm is getting pretty stiff. Lol. Also. Today I routed another pee’r out the side. Pretty sure I had too much water going through the exhaust/waterbox. Taking it down to test as we speak..

[@JoelArseneaultYouTube]

@@StefanMailey Aaaah yes, too much water could do it... and even if the carb isn't bad now, a stiff diaphragm needs to be replaced. 👍

[@jacobcannon6134]

Awesome video and build Stefan!

[@StefanMailey]

Thanks a lot! Appreciate your kind words!

[@jacobcannon6134]

@@StefanMailey this video truly helps a lot. Been thinking about doing this myself. I have a 650 motor sitting around and a 440 hull.

[@StefanMailey]

@@jacobcannon6134 Thanks, Jacob! I forgot to show the electrical.. Using the 440 ebox. I might edit a quick vid and post soon! Appreciate it buddy!

[@JosephDredd31]

They used to make conversation plates that were plug and play.

[@StefanMailey]

Not sure what you mean by that. A few companies make the conversion plates. They all work the same way. I had a friend machine one that was replicated from a well known one. They just bolt on. You use your own bedplate. Works great! 550 is much easier to work with. 440 has to be lined up, dead even. Takes a little more time..lol. Thanks for watching, Joseph!

[@JosephDredd31]

@@StefanMailey Back in the day, Early 90's many after market companies made a aluminum engine plate that would allow you to install a 650/750 engine in a 440/550 stand up Hull.

[@StefanMailey]

@@JosephDredd31 The one I used was a copy of a plate that is still made today! I believe there are 3,4 different companies that still produce them! Im guessing you use to or still, ride ski's?!

[@WVdavidB]

Ive been eying a 440 with rear exhaust or a 550SX for this very reason. Orma 750 i happen to have lol...

[@StefanMailey]

The 440 rear exhaust is a bit of a unicorn 🦄. Not very common. If you do a 750 swap. Will you also do the 750 pump conversion?!

[@jagg5474]

What did you do for the coupling

[@StefanMailey]

440 pump side and 650 motor side! Unless I used the 440 also on engine side.. They're all the same except one of them might have a longer snout. What do you have?

[@CreamsicleMoto]

So when you sold this ski was it all sorted because im pretty sure Im looking at buying it now

[@StefanMailey]

@@CreamsicleMoto Ran great, for me. Sold it last summer. Turn key.

[@CreamsicleMoto]

@@StefanMailey okay I like to hear that because the photos have it looking a little rougher than it does in your videos and this would be my first stand up ski so just trying to get as much info as possible on them

[@RyanMcIntyre]

Hey great video on the conversion! I'm going to be doing the same on my channel this year or the next. I've built 328 racing 440/550s but never anything with a 650 conversion - any advice?

[@StefanMailey]

Make sure you consider impeller and/or pump conversion.

[@RyanMcIntyre]

@@StefanMailey I was hoping to stick with the 550 pump for a season or two before squeezing the big boy in there. What impellers are working for you?

[@StefanMailey]

@@RyanMcIntyre I ran the stick 440 impeller. Lol. I sold the ski a few weeks later. Purchased a SuperJet. I miss the 550 hull though. I think you’ll wanna run a 18-19 pitch though. Iv heard they work pretty well with the 550 pump!

[@RyanMcIntyre]

@@StefanMailey Thanks I appreciate it!

[@sethschroeder9490]

Are you using the 550 e box? If so, how did you go about it?

[@StefanMailey]

Yes. 550 ebox. You just need the voltage regulator out of the 650 ebox. Fits in the same spot. You may have a ground wire left over..

[@fatalaquatic9759]

Hey stefan im currently doing a 650 swap into a 550sx and having trouble with the wire set up any tips an tricks on to tackle that job do you use the existing plug or have to wire everthing up seperate please an thank you by the way your build came out clean

[@StefanMailey]

You can use the 550 electronics. You need to swap in the voltage regulator from the 650 ebox though. I should’ve showed more of that in the video. My apologies. I forget to hit record sometimes… lol. Thanks for your comment on the build, much appreciated! Does that help any?!!

[@fatalaquatic9759]

It helped a lot but now I’m stuck I have a red an grey wire left with another one being black an red would I connect the red solo wire an grey solo wire with the black an red together?

[@StefanMailey]

@@fatalaquatic9759 If I can remember.. I connected the red and grey together. The black was left as an extra ground. One is a pulse and the other is exciter. I don't have the ski now so I can't check. Try connection the red and grey together and check for spark.

[@fatalaquatic9759]

I appreciate the help I’ll try that way I wish there was a way to send you a picture , it’s hard dealing with wiring lol the rest was easy hopefully I can get it dialed in thanks again

[@StefanMailey]

@@fatalaquatic9759 Do you have instagram?

[@paulyshore98]

Haha that pipe will be rusty af after hitting it with a steel wire wheel 🤡🤡

[@StefanMailey]

Stainless steel doesn't rust....

[@StefanMailey]

You do know that nothing in an engine bay rusts, correct? Everything is made out of aluminum and stainless steel, right? You also know that pipes are made out of stainless steel because water actually runs through it to cool the exhaust couplers..and waterbox..and helps tune the pipe.. You also noticed that the pipe was already bare stainless before I cleaned it up with a wire wheel?! Its the easiest way to polish a "stainless" (rust proof) pipe. Clown emoji was a bit much..but hey. Your opinion is cool.

[@paulyshore98]

@@StefanMailey unless your wire wheel was stainless, it will rust. Once you scratch stainless with a ferrous metal, it’ll continue rusting unless you passivate it. But you knew that already…

[@StefanMailey]

@@paulyshore98 HAHAHAHA.... Huh. 35+ years and have yet to see that happen. Hey man. Ill leave your comment up. It's pure awesome!

[@StefanMailey]

@@paulyshore98 lol. It is a stainless steel wheel. Carbon steel wheels are dark.. (not that it matters) You know that too though. Anyways, thanks for watching, brother!