RESTO I'm building another X4

[Matt Braley]

I love rare "go fast" parts and my carbon fiber hulls but I need other traits from a modified ski these days. At this point I already have an ultimate version of all the older Seadoo performance models and I'm still most at home on a X4. These days I'm exploring rivers mostly so I need range. I also need a ski I can skid over an unseen rock in a dark river with without it being the end of the world.

My hull choice will be the 98SPX. It is a little lighter then most X4's and the black bottom is the easiest to repair if necessary. I've had this old race hull for a couple years now and it is it's turn to be saved. I love the look of the old race hulls and there is always a boo boo here and there already so thats guilt free daily abuse. Plus there is the chance that the hull has been trued which would give it a little better speed and handling.

 

[WhiskeyD]

Awesome, can't wait to see the progress

 

[Matt Braley]

Yeah I plan to throw it together quickly. I'll get better pics soon.

Today I pulled a 787 bottom end apart and started cleaning things up. Had to drill several broken bolts but now it's looking pretty good.

 

[glsmohio]

So we thinking stock with big fuel tank or go fast parts as well
...

 

[Matt Braley]

Yes a big tank, rare aftermarket pipe but I have to stay away from big carbs. I'm even thinking of re-jetting 38's from a 717. I'll save big top speed for another build but I won't settle for performance that's less then stock. I can go up to true bore 40's if I had to.

 

[jdanthony]

Looking forward to seeing this build!

 

[Ankeneyou]

Let's see a crazy custom aluminum fuel tank taking up the whole nose! Looking forward to watching this one Matt.

 

[Matt Braley]

Well I've spent all yesterday and today just breaking down the bottom end and putting it back together. It looked good and if it was a flip ski I would have just started building the motor up from what I had. This way I've got the peach of mind knowing that all my bearings are perfect and it now has new seals.

The cylinders that came on this engine had some mods though. Look where they have carved away the back of the sleeves. I was gonna ride with it, even found 2 usable .050 over ProX pistons that fit them perfectly.

When I got to the RAVE valves I noticed that they had routed the cylinders out in that area to run 951 valves. My issue is that one of them had lost it's threads and the shafts on stock 951 valves are longer. I guess I can try to cut one down and then buy a die to make threads on the shaft. These 787 housings have also had O-rings installed on the inside. Now that I think about it I may just go with normal cylinders on this build and save these for someone trying to get the most out of a 787.

 

[rooster18]

Excited to see the build. I'll be watching

 

[Matt Braley]

Thanks for following guys I appreciate it. Last night I was thinking I might as well spend a new OEM NOS set of pistons and cylinders. The hoarder in me wants to save stuff like that for later but I realized that now is later.

I grabbed a pair of OEM wrist pin bearings and slapped them on there. Caged bearings are fine but the old needle bearings are the best, more coverage. I am using a Cometic top end gasket kit. It's a respected company and I've read where they will make you custom gaskets in different thicknesses. As always I had to trim the base gasket because it overlapped where the cases came together and would have disturbed flow. I put a thin coat of the Threebond 1211 on either side of the base gasket cause I'm not having any air leaks.

Normally it's a game of testing different base gaskets to get the squish band into the place that you want it but I have a ton of different cool heads to try. So I put the exhaust manifold on that I intend to run to line the cylinders up and then torqued them down. Grease on the threads and 1211 under the heads.

Speaking of heads, my first choice was this Miller/Buckshot style with 43cc domes. When I went to measure squish it was way too tight at 42ish. I'm looking for between 50 and 60. I think I'm going to be OK with this Westcoast head though. You can see in the pic that the dome in this head has a little ridge to it and the Miller dome I tried first barely has enough to catch a finger on.

 

[glsmohio]

What kinda pipe u going to run matt?

 

[Matt Braley]

I'm going to try my Jet-Pro. It looks like the Coffman and Rossier 951 pipes. The ads in the old magazines say "you don't need a rev limiter" haha so that makes me think it was a dud. I have had it a long time and just want to see what I can get out of it. On this build I'd be happy with a little over 7000 rpm.

 

[emspjay]

Awesome! Can't wait to see this one all done! Subbing

 

[Matt Braley]

I got a full day in today. The Westcoast head gave me the desired tolerances so I went ahead with the assembly. I'm going with all new OEM RAVE parts. I laid them out for a pic. Many of you have probably been surprised at how crazy expensive this stuff is, I know I am. Luckily I picked this stuff up years ago so the sting has faded away. An O-ring make the perfect support for the bottom of the bellows.

I thought about not painting it so it it would just have that random "rat-rod" look but decided to go ahead and spray it. The ski is all black and white so I went with black w/white splash on the longblock and white w/black splash on the bolt on parts.

I went with a post-97 mag cover that had the winged ignition pickup support and the later 787 black flywheel. Rubber seals got a thin coat of waterproof grease and the mag cover gasket and front crank seal were replaced. I used a started I got off a GTX with only 31 hours on it.

 

[mikidymac]

Looks good but funny with just the mag housing white.

 

[Matt Braley]

Well that was just as far as I got yesterday. Today I got the exhaust manifold and rear mount bracket on. She is looking more balanced out now. I splashed the white 97SPX waterbox and the starter with black dots also.

I brought the hull in today and got some work done on it. They had a Mikuni hi-flow external fuel pump mounted in the hull with a stock carb support bracket. It and the mount for the grey box had to go to make room for the big tank. I found a clean fuel baffle that worked, rubber straps and a nice oil tank in my stuff.

I threw in a pic of the Jet-Pro also.

 

[Matt Braley]

Today I went in and got the sponsons on with my sons help. I saved these white Beach House for myself. With the black backing plates they fit the color scheme perfectly. I have aluminum backing plates on the inside opposed to washers and lots of Black Ultra rtv.

I've had a R&D steering setup that someone painted blue. I'm just gonna spray it black and run it.

 

[Matt Braley]

I got back on it today. I got a lot off different random tasks knocked out. I had not put an oiler on it yet because the drive gear just didn't look right to me. The pre-China Hot Rods crank I'm using did not have the square center cut in to the flywheel end. I used a 951 drive gear at first because those go over the flywheel nut instead of in the crank. I ended up pulling the front off a later model 787 and sure enough the drive gear was longer so I'm using that one.

I broke out my ugly old R&D steering setup. I hit it with Aircraft paint remover and a little Emory cloth, then re-spayed it in the black w/ white splash motif. Mocking it up went a little rough and I knocked some paint off the bottom but I can touch it up later. I went to the hardware store and bought new stainless for everything so that's always nice. Notice the home-made pivot piece on the bottom there. Glsmohio made that for me.

I put on a new filter/water collector and a new OEM fuel valve linked with 1/4" black automotive. I also ran oil lines(new oil filter of coarse) and the cylinder drain line going to the exhaust outlet. I threw a good used front mount and battery box in as well.

I went back and read that GroupK write up I was thinking of where they tried 38mm 717 carbs on a 787. They only lost 1 mph and gained 15% more fuel economy so I'm going to give it a try.

 

[WhiskeyD]

Lookin' Good! Interested to hear how the 38's work out

 

[glsmohio]

this thing is looking really good...about time to start planning a ride in fl for the spring

 

[Matt Braley]

I'm happy to have another productive day to report. I got the fuel fill plumbed and I did my best job yet. On my carbon X4 I just pin loose items under the tank straps. This time I rose up and cut down a storage bin so that it will work with the big tank. I also relocated the front ebox mount in front of the tank. A 96-97 GTX grey box has the long 6 pin pigtail that will reach the engine from there.

This storage bin has a lot of holes up top so the air induction single gauge carbon fiber hood I'm using will still have it's benefit. More on that hood later. I've decided that a fuel gauge will be my choice for the gauge hole. I might add a depth finder later but I can drill the dash and put it in the XP800 location.

I put a choke cable and DESS post on today as well as a few more small tasks.

 

[Matt Braley]

Had another big day. I got a set of 38mm carbs from a 717 rebuilt and rejetted. I am trying 80 lows (I will run flame arrestors) and 140 highs. Pop off is 28-29. All the fuel lines are finished.

The engine is dropped in and aligned. I put a Solas pump and prop on it and just went with a stock driveshaft and carbon seal setup. All the waterlines are run except for the pissers. I jetted the waterbox with a 140 and the stinger fitting with a 100. Both are fed from a self cleaning billet strainer so the jets won't clog.

I'll get a minute to work on it tomorrow but then it's going to have to wait until Monday.

 

[rooster18]

Nice progress. Keep up the good work Matt

 

[Matt Braley]

Thank you.

Today I got the handle bars on and the egt gauge mounted on them. I had to redo the ss bracket but it turned out nice. The throttle and choke cables are adjusted and I got adaptors and an old K&N flame arrestor on it. I got the bilge pickups installed in the hull.

I am going to use this old set of Nozzles made by Ultrac. They are supposed to have an advantage but I've tried a set before and lost a mph below what the R&D 85/88 were giving me. It will be fine for this built though. I've decided to plug the VTS hole and just go without trim. With aftermarket sponsons, intake grate and trim tabs this thing will stay planted for sure.

Sorry no pics today.

 

[mikidymac]

Please ditch that K&N Matt.