6m6 in js550

WFO Speedracer

A lifetime ban is like a lifetime warranty !
Location
Alabama
Are you referring to me?
Mine is a stock 1991 440, nothing replaced or changed.
1990 SX is not the pink lightning, only 1991-1992 550SX were the pink lightning.
1990 SX looked like this and was the SX hull but with the old piston port 550.
View attachment 410671
Yep back in the day when I worked at the Kawi stealership I had one of these as my personal demo ski
 
Just got the prop, struggled with getting the old one off, ended up having to cut it off with the death wheel. What a mess! And the solas tool got stuck in the pump, so I fought that out. Now I need to bolt the new skat impeller on. What's the process for spacing it in the wear ring? I know there are spacers involved, do I torque it down and check wear ring spacing? I imagine it all needs to be torqued down for an accurate feeler guage test due to the conical shape of the wear ring.

I was riding my superjet last weekend and met a guy with a 650 Kawasaki swapped 550. He let me ride it for a few, I'm really looking forward to this ski being up and going if it runs anything like that did.
 
Got all of the kit in, and engine mocked up in there. The battery is not easy to access and it takes a different smaller size. Luckily the superjet engine fires instantly compared to a js550 so I'm not too worried about the smaller battery. I need to figure out what I am going to do for exhaust hose because for now I'm going to run a stock waterbox.
 

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Update.

I got the engine in. Plumbed up cooling lines, wired, fuel lines plumbed, exhaust hooked to waterbox.

Getting the water line on was challenging because it's so close to the hull on the stock exhaust, and the ski is narrower than a sj.

I got a radiator hose from oreillys that was 2.25 tapered to 2.0 inches the sj exhaust is 2.25 and the js550 waterbox is 1.75. So I put a clamp on and just squeezed it down. Seems solid to me, time will tell.

One concern I have is the back of the exhaust is touching the ebox. I took the nylon spacer off the mount so the ebox can be closer to adapter plate. I know others have run this pipe in here with the rhaas kit, maybe they can chime in.

It fires up like every js550 wishes it could fire up. Probably try to test on it today or tomorrow.

I need to buy a throttle stop clamp from autozone, but looks like stock cable will be fine.
 
I also had to swap the coil from my superjet since it had wires for a wetjet sit down. The regular superjet wires were too short.
 

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This is so rad! A super reliable JS hull has been my dream forever. I'm in the process of swapping my 62T 701 into a '90 550SX hull. Ive been trying to decide what to do about the exhaust size reduction at least temporarily, as I later plan to widen the tray and increase the size of the rear exhaust. I'll be interested to see how your reducer hose holds up. I'd also love to hear what people have historically done about the exhaust transition.
 
The exhaust hose survived the first outing. I dont think it will be an issue, I had to basically do the same thing when I put a wetjet pipe in my superjet, it's had at least 10 tanks of gas put through it, and the hose looks fine on the superjet.

One thing I discovered was it has some vibration. Maybe it's the polyurethane motor mounts, I've heard they can cause vibration. Or it could be that I hadn't trimmed the hood vent enough and it was up against the exhaust. I will recheck and make sure the couplers are lined up correctly as well.

The ski definitely feels more significant as far as weight goes, but not in a bad way. Much better throttle response! I need to do more fine tuning, and I ordered a R and D aquavane to help the pump stay wet.

I rode my bone stock 1985 550 right after. I'm not sure how I used to ride stock 550s, I mean they are still fun, but definitely need more throttle response and power.
 
I also was looking at the ski this morning before work and realized I had disconnected the primer when I pulled the 550. But never plugged the "t" where it came out of the fuel line. How it ran as well as it did with that fuel line basically pulling air in with fuel I have no clue? I'm lucky it didnt seize or even overheat. But I'm guessing that is contributing to my vibration.
 

smokeysevin

one man with a couch
Location
Houston
What size is the stock battery and what size were you thinking about going with?

I am leaning towards a 12 size in mine but I don't actually know what stock is for the JS.

Sean
 
I'd be happy to share the parts I used on this swap:

1. Rhaas 650/701 yamaha kit
2. Gates radiator hose #20431
3. Skat impeller 19 degrees
4. Dorman-Help cable stop clamp #03336 (4$) (I took the smallest one in the kit and reduced its size to fit the sbn44 using a piece of sand paper and a drill, primitive but effective). I was able to use the old style cable with clamp this way and didnt have to buy or feed a new throttle cable through.
5. Wet jet Kraze coil and wires to reach spark plugs.
6. Duralast etx15 AGM battery.

I think that is all that is involved in this swap. I'm excited to take it out again now that I have worked out a few of the kinks.
 
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