300/440/550 My First JS 440 Rebuild (:

[armymen0268]

Hey guys! Just going to start fresh and let everyone know what's up. So my names Bo, I'm 15 and last year i found a js 440 for free, Rebuilt it for $100 and ran it all summer. So towards the end of summer, actually about exactly a year ago, I was out for a ride and saw a pretty big cruiser so i went to jump the wake. I hit the wake and everything was fine until i landed, The engine started popping like a cap gun and then after i started to head back it died. I swam it to my Local ski show dock and took the hood off to find nothing on the outside wrong. I sat there for a good 15 minutes and tried to start it again, it fired right up so i put the hood back on and i went back in.

I told my dad and he said there might have been a problem, so i took my rear spark plug off and it was all, almost like black rust, all over the bottom of the plug. We thought it was nothing and went out and got new plugs. Came back, put the plugs in, and off i went again. Everything was fine because i live in a bay with an idle zone, so i got to the end of the bouys and gave it some gas and off i went. "It was just a bad plug" as soon as i said this, my engine compartment goes BOOM! lol not really but it blew my rubberband off my hood. I freaked out and went right back in.

So from then on we just took it back to my hometown to the marina that i had it rebuilt at. The guy took the top end off and said "yeah no big worry, i'll have it done in a week." Well now 12 Months later, i still have a blown motor. But this is where the fun starts!


So a couple of weeks ago, my dad came across a old 440 that some guy wanted for like $800 bucks. He started talking to the guy and he ended up saying he had an older parts ski, so after my first Varsity football game as a freshman i went up and got for $100 and took the sucker home and pretty much took her completely apart!

To end my whole life story, were using the new ski to rebuild my old ski! The new ski is the Red and white one, I'm rebuilding the White and Black one!

 

[armymen0268]

This is going to be the highlight of my ski, FINALLY i can use my Supertrapp Exhuaust!

She's a junker, Two broken Motor mounts and one is "Working" condition. She'll be my, "mom im bored of xbox, can i go Tear apart my ski?" Excuse

These next few are my old motor, i took the carb off it because it was in WAY better shape than the BN33, i'd really rather have the 44 on it anyways


Oh and i actually got the motor running! It had been sitting for 8 years and with my magic touch i actually got it started in until 10 button pushes of the start key!

-----I need a water proof switch for my bilge, anybody know a cheap solution?

 

[N2 H2O]

Nice build you got going on. You won't see much of a power gain from the supertrapp without an aftermarket pipe and it doesn't even make a huge difference then. I just use the cheap toggle switches from lowes for my bilge pumps. I mount it on the under side of the handle pole. Here's a pic of where I put it. It's kinda hard to see, but it's on the lip that curls around the sub plate. I would look for a jetpower exhaust. They came stock on the 86-90 550's. It isn't as good as an aftermarket pipe, but it's a major improvement over the stock 440 pipe. You can find them for really cheap. I think I have one laying around if your interested.

 

[armymen0268]

Nice build you got going on. You won't see much of a power gain from the supertrapp without an aftermarket pipe and it doesn't even make a huge difference then. I just use the cheap toggle switches from lowes for my bilge pumps. I mount it on the under side of the handle pole. Here's a pic of where I put it. It's kinda hard to see, but it's on the lip that curls around the sub plate. I would look for a jetpower exhaust. They came stock on the 86-90 550's. It isn't as good as an aftermarket pipe, but it's a major improvement over the stock 440 pipe. You can find them for really cheap. I think I have one laying around if your interested.

Yeah, if i can find a switch that i can mount on my handle poll i'll be fine! but Yeah i knew it wouldn't be much Horsepower but it sounds pretty sexy lol i looked up those and they look pretty big, i kinda wanted to keep it a light weight ski with some room to work. I probably could get a new pipe but i just rebuilt the ski and haven't had a water test. I don't even know if it will run! But thanks for the offer

 

[N2 H2O]

I've run a supertrapp before and it sounded pretty mean. If you feel like having fun a day take out the waterbox and run just the resonator. One of my skis came setup like that and it was the sickest sounding ski on the lake. It was a little loud, though so I had to put an inline silencer in. The bilge switches are only a couple bucks at lowes and seem to hold up pretty well. Good luck with the build!

 

[armymen0268]

I've run a supertrapp before and it sounded pretty mean. If you feel like having fun a day take out the waterbox and run just the resonator. One of my skis came setup like that and it was the sickest sounding ski on the lake. It was a little loud, though so I had to put an inline silencer in. The bilge switches are only a couple bucks at lowes and seem to hold up pretty well. Good luck with the build!

Yeah after my old box broke i had to run it with a straight pipe and that's how i blew my motor!! lol thanks, i appreciate it!

 

[armymen0268]

This is for the exhaust...Running a stock 440 Pipe (I believe) to my Supertrapp Exhaust!

Here's half of her!


Oh and Edit: My dad made a V with some hoses and got my pisser hooked back up, even tho it's not that big of a deal! Video coming soon, the sound quality is a bit off. She sounds like poo...but in real life she sounds pretty mean

I kind of sounded stupid, it kind of sounds like i don't know what i'm talking about but i do lol I'm bad with videos

 

[armymen0268]

A Storm just rolled in so i thought this would be a cool picture to start out this next post!

Okay guys, so my first ride was sunday night, around 7 p.m., i got down to the ramp and me and my dad backed the ski in and she fired right up. So we sat there, waiting on my pisser to start pissing (to let us know that water is pumping) and she never did, so my dad thought he put the muffler on wrong. After about another hour of waiting (waiting on my dad to change the direction of the muffler) We got back down to the ramp and she fired up again and i sat there and waited and she didn't piss at all. So i told my dad, "we just rebuilt this ski, and i want my 30 seconds of fun." and my dad said "well go ahead then" so i took off. Now where my boat ramp is, it's all idle zone for a while and even past my lake house. So After a few seconds of riding i glanced over and she was pissing very hard so i felt good! So i pretty much ran it at Half Throttle all the way out until i could get past the bouys and i took off, Stood up and she was running great! Well guys guess what? My wish came true, 30 seconds later she died!
Well my dad then came out in my grandpa's pontoon, we took the hood off in the water and the first thing i looked at was the Piece of crap Rubber Supertrapp waterbox piece. It was ripped in half just like the other. (Picture somewhere in post after my dad ripped the extra off)

So This is where my dad said, no more rear exhaust! On a 550 Body, we made it into a real 440! lol From the other jetski i bought, we just converted the old side exhaust and everything seems to be mounted up correct!

 

[hillbilly550]

that blue jug has been ported
the old Finned exhaust manifold is high performance as well
i may have a jet power exhaust & a water box if you are interested

 

[Joker]

Nice build dude. I'm starting my 300/650sx conversion. I hope we can ride next summer

 

[armymen0268]

that blue jug has been ported
the old Finned exhaust manifold is high performance as well
i may have a jet power exhaust & a water box if you are interested

Thanks for the offer but as of now i'm going to be looking for a SN 701!

Nice build dude. I'm starting my 300/650sx conversion. I hope we can ride next summer

and yeah man that'd be pretty dope. I haven't even been on open water for more than a minute this year! lol