Alumacraft MV1448 Seadoo IB jet, Still jetting

[Ranchero50]

Ok, took it out last night, no pics this time, but it absolutely flew across the water. Everything even held together. The bad was both batteries are crap, had to buy a new one ot NAPA to get it to start and the second bad was losing one of the tackle bags out of the boat going down the interstate locked in traffic in the fast lane, hit the next exit and saw some guy jumping in his car as I went back by with it... About a $100 gift to someone and of course I didn't have any info in it if the guy was going to return it... At least it was the backup one with the lures that didn't do very well (x-raps, shad raps, cranks, etc).

Still, did I mention that the boat was running very well. I put the small expansion pipe back on and this time the motor revved clean up to 7k and the pump stayed loaded and we were up to 49mph on the depthfinder. The water was like glass and the spray pattern off the side of the boat was out of my line of vision (further back than it's ever been). I think the only thing in the water was the spoon and back 2' of the hull. Almost two miles to the fishing spot and we were there in a little over two minutes.

The Mayfly's were out in force so it was top water twitching rapala original floaters 2 1/2" silver's. The water was almost gin clear too 3-4' deep and the bass were on the top rolling everywhere. Took on about an inch of water up front in three hours or relaxing. Saw two other boats going up to night fish. Beautiful evening on the water.

Jamie

 

[RBuffordTJ]

Absolutely amazing. I have been going page by page through this thread and hope you pop back to post final pics of the shallow water monster soon.

Bufford in Orlando

 

[Ranchero50]

Bufford, the boat has exceeded my every expectation. Honestly the only thing I'm not real happy with is I messed up on trimming the trolling motor shaft and had to recut it 2" shorter and sometimes it'll cavitate if I'm fishing off the other side of the boat.

I redid the steering too last week, moved the pivot point out further on the steering wheel shaft and now I can get 24` of steering either way, before it was around 18`. Makes idling manuevers simple and at speed I can dodge the weedbeds easier. The boat handles like a sterndrive boat too, no forklift sliding at speed like most outboard jets. It's real stable and smooth at speed.

The local river has weeded up, turned into a pasture. I figured out that if I idle across the heavy fields diagonally going downstream that the jet won't clog. Once in the clear channel I can crank it around and let it run free dodging the areas where the grass is on the surface. I have to cut behind one island and shoot a 20' wide 1' deep gap at speed to get through but noone else is up there except the Mexicans swimming and they get out of the way pretty fast when you're coming at them at 49mph :shock:

The boat is fun, light and easy to load. Just back the trailer until the back roller is wet. I put an aluminum diamond plate deck back the spine and walk out to the axle on it. Let the boat drift down until the center strake is on the roller and pop it up on the bunks. I put strips of UHMW poly and they are worth everything for loading the boat.

The hulls is leaking too, but only where I welded the revit holes shut, go figure.

Jamie

 

[RBuffordTJ]

I am thinking if you came at me that fast I would get out of the way too. Diving might be best at that point!

LOL

It is such an cool rig, you wet out of your way to really do it right and it shows. As for the bottom leaking some have you considered something like SteelFlex 9x-2000 for that? I love it on mine and it looksl like there is a plastic sheet on the bottom of my boat now, no rivit can leak even if it wanted to. They have been using the original stuff no airboats for years, the newer formula is stronger.

Hope to see some video of that thing running wide open! My sister lives in Southern Maryland, Lusby is the town, (I think I saw you were in MD) I'll give a shout if I get in the area and bring my HD camcorder. Love to see you blast past a few times.

Bufford

 

[Ranchero50]

HD would be cool, but it'd probably show all my grey hairs... Took her out this evening solo and it finally hit 50.2mph and was porposing a little running that light. Still the old girl was really agile dodging the weed clumps.

Jamie =D>

 

[goose775]

wow. i just read this whole post today. yesterday was my first time here. ive gotten lots of good ideas. jaime id love to come see that thing. i live 2 miles away from quad in hedgesville. i have a lot of friends out there at quad. u probally remember ben from the machine shop, hes out at the guard now. anyway ill get into details of people we know another day. id still love to see that in person, to really see how complex it is. all im doin is puttin some small decks on my 12'er for trollin motors. any way let me know if itd be possible for me to ride out there sometime or if ya jus wanna run it to work with ya one day. i go past there everyday about the time for shift changes so timing wouldnt that bad if u were to bring it with ya. either way.

 

[Ranchero50]

Goose, I worked in Press Maintenance with Ben when he left the machine shop. Ask him about Jamie. Pm or email me your number, I was out last Tuesday evening solo down at Williamsport looking for fish, always looking for someone to go out since the kid lost interest... Hit 53mph on the wheel and chased down a 1860 G3 with a 90/65 Merc on the back.

The boat is still deckless, it takes on some water through the porous welds but I plan on Steelflexing it this winter if I can get it back in the garage. The carbs were acting up coming home last time out, got to playing around and jumping my wake under the bridge. Lots of fun. Overall very happy with the project.

Jamie

 

[CRAPPIE_SLAYER]

That is one SWEET ride! =D>

 

[sdog53502]

That is sweet !!
I have a 16 x 48 with a 650 kawi and a tigershark pump. I am having some problems with cavitation unless the water is pretty flat. Do you think the revised intake helped more or do you think the spoon is the hot ticket ??
Thanks
Steve

 

[Ranchero50]

Steve, the spoon more than any other thing. The hydrodynamics of the original intake was decent, the front wall was a little abrupt, but it would still pull water into the inlet on flat water. With a little chop the boat rode higher so it was injesting air between the waves. With the spoon addition, the spoon was still in the water in mild chop so cavitation was much less. In fact, at speed the spoon is right at the leading edge of the water under the hull. I'm amazed this boat does as well as it does.

A 650 in a 16-48 should perform well, similiar to a 60-40 jet if not better. You could mock up the spoon out of fiberboard or something similiar and glue it on to test the design if you don't have welding skills. Your tigershark intake should be fine if the boat sat further in the water but since it's so flat and big you are n't displacing any water on plane and it's sucking air right down the strakes.

Jamie

 

[sdog53502]

I have a Hobart 135 that I can kind of weld aluminum with. Otherwise I bought some braizing rods I am going to try. I will give it a shot in the spring and see if it helps. Where did you come up with the spoon design ?
Thanks !!

 

[Ranchero50]

The spoon was designed by looking at the bottom of a spoon... :mrgreen:

Seriously, holding a spoon veritcally slide the bottom of a spoon into the water stream coming out of your faucet. The water will follow the curve and shoot towards the top side of the spoon.

I just figure that I'd need around 3' of pad or spoon to get a nice smooth curve up into the jet inlet. The harsh cut of your center strake is hard for water to go around and it's cavitating there as well as letting any air that gets trapped between the hull and water flow up into the jet. it may be worth your while to make a spoon out of wood and silicone and screw it to the hull to see it it works for you.

Jamie

 

[JBoze]

Very cool boat!

 

[Ranchero50]

Been a while, in early December I was given another Seadoo, a '95 Xp that was completely intact. Found out it has the pump housing extension and most of the parts are in better shape than mine. Took some playing but it finally ran, had a rod out and the cylinder walls were pretty scored up. I parted it out with everything sitting in the boat outside under the cover.

Hopefully I'll get it inside before fishing season. I need to go through the carbs, the secondary is leaking fuel at the diaphram and I cracked the exhaust manifold when we got an early freeze and it wasn't drained correctly. Plus I still need to finish the decking and make it nice with carpet etc.

Jamie

 

[rock_smasher]

Hiya Ranchero, nice to see you again! (fellow pwctday'er) I know its been said, but your fab skills are amazing! Great to see this quality of work. After reading the early part of this thread, I started looking for my own boat- couldnt find a tin-boat that i wanted. Found a 15.5 kingfisher fiberglass that was perfect except it wasnt tin. I'm robbing parts off an old kawisaki TS, and grafting the donor piece in, hope it comess out good. (pics and a build thread coming soon)

50+mph, just awesome!! =D> =D>

 

[sdog53502]

Well I started beating on some aluminum to make a spoon. Time to flip the boat and try to weld (or braze) it on.
Wish me luck !!

Steve

 

[Nevillizer]

Good luck (as requested).

 

[sdog53502]

Some pics of the spoon....

 

[Ranchero50]

Looks pretty good so far. I would suggest trying to get the hump (where you notched the sides) a bit flatter. The goal is a smooth curve from the front to rear. My only fear is if the break is too abrupt at the notch the water may decide to cavitate there. How high is your spoon now? Mine only ended up being about 2" overall, about 1/2" deeper than the keel strake.

Today I did pull mine out of the garden, getting it ready for the season.
Jamie

 

[sdog53502]

I have been trying to get it a little less abrupt, not easy to do when all you have is a rubber hammber and a vise.... Mine is around 1.75 at the tallest point. I may need to do a little trimmng to the rib on the boat.

Noticed on craigslist that there is a 750 kawi for sale for $450 near me. I wonder how many MPH that would gain me ??? :?