1975

Kawasaki JS

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Specifications

Model: 1975 JS 400

Engine: 1995 750 SXi

-Porting: JCS Engineering

-Head:  Westcoast Removable Dome Type

-Carburetion: Dual Green Modified Mikuni 46mm On R&D Intake Manifold.  Ocean Pro Vortex Air Filters.  Primer Starting Fuel Enrichment System

-Reeds:  Carbon Tech W/Boyesen Stuffers

-Exhaust System:  Westcoast W/Jetcraft Engineering Rear Exhaust Kit

-750 Into JS 400 Adaptor Plate:  Jetcraft Engineering

-Ignition:  Stock 750 SXi Electric Box.  Jetinetics Aluminum Flywheel.  Timing Advance Plate

-Billet Couplers

-Satin Black Powder Coating By Sean Murphy At American Powder Coating, Auburn, Washington. 253-833-7870

Hull:  1975 JS 400

-Paint By Harold's Auto Rebuild, Renton, Washington.  425-226-5000

-Original JS 400 OEM Sticker Package Reproduced By Nichols Design, Auburn, Washington.  253-833-6688

-Nose Exhaust Removed.  Rear Exhaust By Jetcraft Engineering

-Late Model Handlepole Crown

-Nose Reinforcement Plate Under Handlepole Crown

-Nose Brace

-On/Off Switch Relocated To Handle Bars.  Equipped With Lanyard.  7 Degree Polished Aluminum Handle Bars.  Ocean Pro Waffle Grips.  Aluminum Finger Throttle.  Home Made Quick Steer

-Handlepole Spring W/Reinforcement Plate.  Waterdog Handlepole Clip

-Rule 360 GPH Bilge Pump

-Hydro-Turf Black Tray Mat

-Miscellaneous Doo Dads:  White Brothers

Pump and Bearing Box:  1989 JS 550

-Impeller: Skat-Trak Progressive Pitch

-Steering Nozzle:  1975 JS 400

-Ride Plate:  1991 JS 550

-Intake Grate:  R&D Toploader

Production Notes:

Special thanks go to many people without whom this project would not have been possible.  Harold's Auto Rebuild in Renton Washington redid a botched paint job and made it look great!  Nichols Design did a fantastic job reproducing the original, no longer available from Kawasaki, 400 decals.   Jetcraft Engineering for the  adaptor plate that facilitates the engine swap, and also made the rear exhaust.  Eric at JCS Engineering who supplied and ported the 750 cases and cylinder.  Chris Finley at White Brothers who helped get all the correct 'Doo-Dads'  for that polished, finished look to the machine.  And Sean Murphy at American Powder Coating who did the satin black powder coating.

The Story:

I got this machine while I was running a Jetski Rental shop.  The owner brought it in. Said it wouldn't run. The original 400 engine needed a complete rebuild.  I estimated approximately $500-$700 for the job.  The owner didn't want to spend that much on the then crappy looking unit.  He owed me about $200 for labor at that point, and asked if I'd take the machine in lieu of the $.  "You Betcha" I said.  I had run a 750 powered JS hull before, so, when I got the 400, I decided to redo it like original cosmetically, but with some serious HP under hood!   I wanted it as close to the original 400 as possible, but would make changes as safety, cosmetics, horsepower, and handling mandated.  The nose exhaust was the first to go!  The rear exhaust is much more sanitary. I considered making the front-of the-foot-tray on/off buttons work, but decided having the on/off buttons at my finger tips was the wise decision safety wise.  The safety lanyard was added latter when I raced it at an exhibition race in 1997.  Jetcraft recommended using a 440/550 electric box with 650 Kawasaki engine ignition components.  I had the stock 750 box laying around, so I decided to use that instead.  I had to make a special mount for it, and had to modify the under hood very slightly to make it work.  It has worked fine, but I may still go to the 440/550/650 hybrid electric system  eventually.  On earlier 750 conversions of this type, I had tried a 440 pump.  Didn't work very well.  The 550 pumps work great. 

So, how does it run?  It's a handful for sure!  After getting used to my Superjets, riding this one makes me wonder how Jacobs, Sheldon, Goatcher, and the rest of the Pro's rode their high HP JS hulls!  I read somewhere Jeff Jacobs' last fuel injected 440/550 race boat radared at over 55mph!  The 400 isn't that fast, I'm guessing 52, and it's the squirreliest thing I've ever rode!  I raced it once, and I was all over the place.  The rougher the water got, the more I went swimming!  Won the race though!

I've kept all the stock 400 stuff.  I'll keep the 400 this way, as the ski in original, tip top tune would get eaten alive by a good running 300!  Not much fun.  But, if the nostalgia craze that has hit classic cars hits personal watercraft, I might restore it to original.  Anemic running 400, ugly nose exhaust and all!

Thanks for visiting the site, and drop me a note if you'd like!