RESTO An Extremely Modified X4

[Matt Braley]

Hey Matt, I find it interesting that your PTO was hotter than your MAG cylinder. I've been trying to hut down the cause of my PTO running 100degF cooler than my MAG cylinder. Some guy on PWC Today said that it's because the MAG has to make such a tight turn relative to the PTO at the Y-pipe. I'm having trouble believing him, as I can't see SeaDoo designing a 2-cyl engine with such a drastic temperature differential. I've been through the carbs, and despite having adjusted the Pop-off to be the same, I saw no other differences. That made no difference. I took out the plugs yesterday and saw that the insulators are both nice and chocolate brown. I guess that's a good sign, though I would really like to get my cylinders to the same temps. It seems that even when I screw the High needle all the way in, it barely makes a difference on the EGT temp on that cylinder. I heard that if it's knocking, it will get cooler (but in a bad way). How can you tell when a Rotax pre-detonates?

Normally it is the rear cylinder that has a problem burning pistons when one starts bolting aftermarket pipes on. You should be OK if those chocolate brown plugs came directly after a long wide open run. Knocking from pre-detonation in these engines means that the top of the piston has bad news waiting for you. It can be caused by low fuel octane(old gas), improper ignition timing settings, incorrect spark plug, lean fuel mixture, etc. You must back off the throttle at the very first "ping" that you here. It is normal for the high speed jet to be closed on these carbs. I like "lightly closed".

I bought a real Coffman's pipe today online(race version with a water jacket) and got a call from that welding shop saying that they fixed my Neptune pipe. I'm very excited about both. I'm bringing my Mikuni carb pop off tester to make sure the Neptune hold pressure. If it does then it's going on this weekend!

 

[IDoSeaDoo]

Matt, how close are your EGTs? The engine in question is not modified, except for the chamfering/cleaning rough casting marks inside the case. Also, how do you know it's pinging? What does it sound like?

 

[Matt Braley]

The EGT's were always moving and I had a red hot pipe under my but. I think they were about 50-80 degrees off but I feel like I could tune that in with the carbs(just couldn't reach passed the pipe).

The pinging sounds like an old car going up a hill in too tall of gear on cheap gas.

 

[Matt Braley]

Neptune Pipe Installed!!

It sounds great on the trailer. I'll get it wet tomorrow. It is reverse cooling now.

 

[Stunnerable]

This is a cool build. I love that trim system!!

 

[Stunnerable]

View attachment 18469Ya Minne I wondered about those sponsons cause the oval part is just cut out of flat plastic but the backing plates are billet and fit perfect to the curve of the hull. I shoulda known that's a little too nice of work for home-made(unless Racerxxx is doing it).

Spim- another Zebra? It could be the Karen Countryman ski I copied! If so it was probably tuned and light weight? I'm just an optimistic thinker.

Isn't that Nick's seat!!??

 

[Matt Braley]

I had it done over at Jettrim per Nick's recommendation. I love the high top but it still feels odd to me when I ride it.

I bought another trim system like that today in fact. Thanks, they are so smooth.

 

[Minnetonka4me]

Great project! Its been so cold up here I havent even pulled my machines out of storage! We had our fishing opener and the Governor was in Park Rapids, MN. The lake was more than 50% covered in ice today.

We have touched 80 once this year, it was 55 today and its supposed to be 92 on monday. Minnesota weather is so effed up.

 

[Matt Braley]

Stunnerable I think I know what you meant by the seat now. Nick's brother Jess(99SPXXX) has one like the seat shown pictured on the Commercial Sewing ski. It has some special kind of air induction thing going on inside it. He may have that actual seat, who knows? They could not have made too many of them.

I fit in a pic of the brass pump because it is ported. I had to pull it to realign the engine so I saw that I currently have a Solas XO in it now. I guess I should have put up a stock pump next to it but someone took the time to remove half the brass from the vanes.

 

[Stunnerable]

Exactly Matt.

Rare seat for sure.

 

[Matt Braley]

Well it ran good and stayed nice and cool under the seat. The WOT runs seemed to peg the EGT's at about 1080(i hope that's OK?). I got past 7200 rpms but only saw 58.2mph. I was kinda disappointed with that but here is were the "tuning" starts. At least I have something pump gas friendly that I feel is safe to put hours on and from here I can try different impellers and jets and whatnot.

 

[Minnetonka4me]

The air "deduction" part of the seat there in the back; It basically allows the engine compartment to breath better and keep fresh cool air in there.

My brother sunk a heck of alot to not only recover but also reconstruct the seat. It was all built out of fiberglass, and he had it reinforced with carbon fiber before Gary made the one off cover. When he bought it it had yellow vinyl on it.

Its funny...my brother almost matched the colors in that picture completely on accident!

Oh and another picture VJS posted this morning...

 

[Matt Braley]

That pic is so awesome!!! Where did you get that? Look in the back at the 96 XP Neptune ski!!!! That might be Mary Ann Sexton with "Champion". If so then I'd give my left nut for that ski

 

[racerxxx]

MB, I'm not sure if it helps any but the hump seat I picked up for my XP was ventilated by a hole saw. They also put the holes opposite the carbs so if there was water entry it would fall on the exhaust side, not the carb side. That would suck if you had aftermarket arrestors. The guy John I got the seat from said it came from Watoose Designs, possibly a seat they had on a race ski or a tuner ski, who knows that's not why I bought it.

There is also 2 "tall" seats on Ebay right now for anyone interested.
http://www.ebay.com/itm/SEADOO-SEA-..._Watercraft_Parts&hash=item43b0784253&vxp=mtr

http://www.ebay.com/itm/JETRIM-JET-..._Watercraft_Parts&hash=item4ac48abb66&vxp=mtr

You can see the other pics in my thread RIGHT HERE

 

[Matt Braley]

Very cool stuff. I've seen that first seat on there forever but that second one was neat. It has a hump in front. Actually that might be a ball buster, I can see why it's a rare choice.

The holes look like a good and easily achieved solution. I may try that if I feel like I'm starving for air.

 

[Minnetonka4me]

Matt the picture was posted on Vintage Jet ski page on facebook.

You arent a REAL junkie till you "like" the VJS page!!!!

https://www.facebook.com/pages/Vintage-Jet-Ski/197254523644900?ref=ts&fref=ts

 

[Stunnerable]

Agreed! They always bring a smile to my face.

 

[Spimothy Leary]

Great project! Its been so cold up here I havent even pulled my machines out of storage! We had our fishing opener and the Governor was in Park Rapids, MN. The lake was more than 50% covered in ice today.

We have touched 80 once this year, it was 55 today and its supposed to be 92 on monday. Minnesota weather is so effed up.

its still cold up there because of your "stein" reference in your email... would you like me to take back my cold weather curse ?

 

[43!]

Awesome setup. Two questions. Where did you get the trim from? Also, what hand guards are those? Thanks!

 

[Matt Braley]

The hydraulic trim by Baker came from the classified section of a pwc site. The hand guards came from ebay. They are off brand copies of Acebris.

The ski is running really good with 6 hrs. on it. I put a Skat 16/24 on it and it liked it better than the 16/23

 

[Matt Braley]

The air "deduction" part of the seat there in the back; It basically allows the engine compartment to breath better and keep fresh cool air in there.

My brother sunk a heck of alot to not only recover but also reconstruct the seat. It was all built out of fiberglass, and he had it reinforced with carbon fiber before Gary made the one off cover. When he bought it it had yellow vinyl on it.

Its funny...my brother almost matched the colors in that picture completely on accident!

Oh and another picture VJS posted this morning...

Well it's time to check in with this thread and update you guys. Fist of all I quoted this pic because what a small world(or industry I guess)....see that lady on the bottom left? That's Terri from Poppy covers. She is the one that made the stripes in the first place. I bought a cover from her (check the sticky) and we ended up talking about it. It was cool to contact the person who dreamed up the scheme that I copied.

So I've worked myself in circles on this thing. At about 9hrs in I saw water gushing into the hull while flushing through a notorious crack in the Neptune pipe. Since I had to pull the motor to change the pipe I dropped in a fully ported Miller racing 787. It ran great but revved up like it was supposed to and ran too hot for pump fuel. Pump gas running was a must for this one so I backed off and put the stock 787 in it. I found a good welding shop to repair the pipes and I have not had a failure since. I've tried different pumps also like Solas and Skat Magnum. So far though the ported brass pump with a really tall Solas XO style (17.5X26.5) has done best. Now I have just gotten back two more XO's from Impros each pitched slightly shorter that that one. I also have a few different nozzle sizes to mess around with as I watch the temps, rpm's and speed.

Yes I now have a real speedo in my single gauge hood. I rose up on one from Speedhut and after some initial trouble I like it. It rained on the first day I installed it and beaded up completely behind the glass. I called them and they suggested I dry it out and silicone the back up which I have. It's doing good now so far and they will warranty it if it fails. They offer two different sizes in the 2" range and I got the smaller one. I should have gotten the larger because there is room for it.

I'm between 60 and 61 mph right now pulling 12 gallons of fuel in the hot muggy Fl sun(a couple weeks ago). I intend to add to that a little now that the air is getting cooler and I have these new impellers to play with. The ski runs fantastic and pulls really hard all the way up to it's top speed after all the little tweaks. I know I could gain a couple easy mph by removing my big sponsons and grate(tried the Inventioneering but went back to Jet Dynamics #6). The one mod I want and don't have yet is a lightweight carbon fiber hull. I will keep you guys posted as I gain a little mph.

 

[Matt Braley]

Well the forum is a little slow today so I thought I would speak a bit on this project. I did get it over 61mph since my last post. The bearings in my "old school" Skat Magnum pump were talking to me a little bit so I sent the pump out to Skat Trak in Cali for refurbishing. It will be back soon, I saw the charge was $200. I have a new OEM wear ring in it and with a fresh alignment I should see this ski gain a little more mph.

I want to talk to Dr. Honda about making a SEA-DOO decal for either side of hull but that is gonna be about it. I do have like 161 psi on one hole and like 170 on the other(Novi head) so a fresh top end would probably be worth another little improvement in speed. I just don't know What more to do to it. The only "mod" I really want that I still do not have is a Carbon fiber or kevlar X4 hull. I have a faster X4 but it requires 112 octane race fuel so that's no fun.

I am driving this baby over to Jacksonville(Atlantic Bch.) this weekend to ride with a couple friends. It's running great and I have been fanning out further and further from the house in my evening solo trips. It is a great piece of mind to be able to monitor the engine temps in real time. Check out this pic I snapped coming in a little late the other night.....you can see the illumination of all the gauges except for the TTO tach.

 

[IDoSeaDoo]

I drool every time I read this thread. As they used to say "You've got my milk bro!" Do you have the bigger fuel tank in there?

 

[Matt Braley]

Yesir. I can fit 13 gallons in because of all the plumbing when it's bone dry.

 

[racerxxx]

That gps speedo looks rad all lit up.

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