Alumacraft MV1448 Seadoo IB jet, Still jetting

TinBoats.net

Help Support TinBoats.net:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
You could probably use a Teleflex push-pull cable if you wanted the trim tabs adjustable. Then a simple lever and pivot mechanism to operate it, possibly even rigged to a foot pedal.

Thought about doing this on my boat, too, as it did want to porpoise a little bit at WOT. I corrected that by removing my ride plate, and giving it a slight downward kick on the last inch or so, by using my metal brake and making a very slight bend. That eliminated the porpoising, but again, I'd like to have it adjustable, so, I may change the design again at some point, and have a push-pull cable like I mentioned.
 
As I am fairly new to the site, I have been cruising the mod section getting ideas when I came across your build. While there are many, many great builds, so far the fabrication level on this one is amazing. Awesome work. Will be checking back for any updates.
 
Thanks for the compliments fellas. The boat is still snug and waiting for warmer weather. I did open up the shed and made sure nothing was living in it. I even sniffed the seats since the smell of marine vinyl brings back memories for me. :)

Jamie
 
Ranchero50 said:
Thanks for the compliments fellas. The boat is still snug and waiting for warmer weather. I did open up the shed and made sure nothing was living in it. I even sniffed the seats since the smell of marine vinyl brings back memories for me. :)

Jamie

Soon the warm weather will return. Was 80 here in North Texas yesterday. I'll send some up your way.

RK
 
Finally dug the boat out since the weather has conspired to make me perspire and the kids been bugging me to get it out.

Spent yesterday afternoon getting it water ready, washing the funk out and putting the exhaust back together. Once done the boat wouldn't run for long. Suspecting bad gas we drained the tank and took it to the river with a fresh full tank figuring it would eventually smooth out.

Didn't work out.

Today I pulled the carbs off and checked them out, put them back on and while it was barely running ran around back and checked the exhaust flow. No exhaust flow, some dumbass hooked the muffler up to the old hull exhaust port that's blocked off...

Runs much better with an open exhaust...
Jamie

PS, we are off to get it wet, us too.
 
Hey folks, no real updates, boat keeps tooling along nicely. We've gotten pretty good at relaxing with it, horsing around on the trip up river and answering questions about it.

We did suck up a bird, fish or something the other week in the dark. Felt the thump and the pump cavitated pretty bad. Idled back to the dock and what ever it was fell out by the time I got it on the trailer.

I need to post up another video or maybe take the boat to some new water but it's just too nice to be on the water fifteen minutes from the house.

Jamie =D>
 
Good to see you're putting it to good use.

How's the fishing?
 
Slow right now. The river is up a foot or so and there's tons of green grass trash floating. The bass aren't where they were when the river was lower and there's more prop guys out now. We did manage to catch an 8" channel cat two weeks ago. Smallest one I've ever seen and it took him 25 minutes to eat the liver off a #4 treble and hook himself.

Other than hooking the exhaust up wrong I haven't worked on the boat this year, just gassed and gone. I keep trying to talk the kid into trying the net a duck on the way up river. He's almost been pooped on a couple times when they rise in front of the boat. Fun times. :wink:
 
Nice looking build from the video you would never guess that it was home built. From the 2 threads you and PSG-1 both have great fabrication skill when it comes to the conversions.

What's the advantage of using a jet ski motor as opposed to just using a jet outboard?
 
Gramps50 said:
Nice looking build from the video you would never guess that it was home built. From the 2 threads you and PSG-1 both have great fabrication skill when it comes to the conversions.

What's the advantage of using a jet ski motor as opposed to just using a jet outboard?



Sorry for the extremely late reply, just noticed that someone else had posted in this thread.

As for your question..... here's some advantages and disadvantages to each one:



With an OB jet, you still have the weight of an engine hanging off the transom, with an IB jet, the weight is slightly forward, making the boat less stern-heavy.




Also, provided that the engine compartment and exhaust system is properly designed, an IB jet is always going to be much quieter than an OB jet. All the OB jets I've heard were as loud, or louder than, a jet ski.




With an OB jet, the water is drawn up vertically, and then turned 90 degrees through the exit nozzle. As anyone who understands the dynamics of water flow, etc knows, anytime you make a 90 degree angle, you lose some efficiency and overall pressure.

With the IB jet, the water is drawn through a tunnel, at a very slight angle, and exits straight through, it doesn't make any turns, therefore, it is a more efficient means of transferring power.


An OB jet's intake grate still protrudes slightly below the edge of the transom, where the IB jet is flush with the hull.


On the other hand, an advantage of the OB jet, is that it can be trimmed out of the water, which is a good thing if you operate in salt, because with the IB, the pump is constantly sitting in salt water. Also, the vertical design of the OB allows all water in the cooling passages to drain out when not in use.

With an IB jet, the horizontal configuration of the engine allows water to stand in those passages, and in the water box (muffler) which means if you're running in saltwater, you either have to haul out every day, or you need a specialized drive-on dock known as a 'sport port' where you can get the pump out of the water, to flush it. Or, you can flush it while it's sitting in the water, as long as you let it idle, and don't rev it. In this manner, garden hose pressure exceeds pump pressure, so, only fresh water is flowing to the engine. But I don't like this method, as you can't "blow out" the water by revving it like you can when it's out of the water.



And finally, with the OB jet, you're still dealing with a conventional steering system, which is 3 turns lock-to-lock, unless there's some specialized system I'm not aware of.

With the IB jet, you can buy a helm that's 270 degrees lock-to-lock, which is what my boat uses, or, for even sharper response, they also make a 135 degree helm. With steering that quick, you can spin the boat 180 degrees in its own length at 30 MPH. I just don't see an OB jet with a 3 turn lock-to-lock teleflex helm having that type of steering response.
 
Thanks guys, I think PSG covered it pretty well. For me, it was all about cost, compromise and desire. I couldn't afford an outboard setup, had a 1448 and a bunch of parts and the desire to make something cool with the tools I own.

So here we are, several years later with a simple boat that does exactly what it's supposed to. It was built for reliability and enjoyment. I still haven't finished it yet, carpet is still rolled up hanging from the shed ceiling. Again, it's tucked away waiting for warmer weather.
 
She lives again. Went out last night for a short test and tune with a fresh tank of gas and no fishing gear. We had a blast, truly acted like a big jet ski. Doughnuts, spins, wake jumping and flat out hauling butt.

Tonight we took it out again for some top water fishing and had a great time. Last years 11" small mouth class are over 12" this year and very aggressive. None were on beds yet but they aren't far off.

No pics or video, just use your imagination.

Jamie
 
[url=https://www.tinboats.net/forum/viewtopic.php?p=320547#p320547 said:
Ranchero50 » 33 minutes ago[/url]"]She lives again. Went out last night for a short test and tune with a fresh tank of gas and no fishing gear. We had a blast, truly acted like a big jet ski. Doughnuts, spins, wake jumping and flat out hauling butt.

Tonight we took it out again for some top water fishing and had a great time. Last years 11" small mouth class are over 12" this year and very aggressive. None were on beds yet but they aren't far off.

No pics or video, just use your imagination.

Jamie

Glad to hear it's still running strong. You put a lot of time and effort into your boat project, and did an outstanding job!
 
Here's my current trailer setup. My river is very shallow at the ramp during late summer so I set the trailer up to get the boat safely wet and dry.

First time I pulled the boat out I went off the end of the ramp and ended up ripping the axle out from under it. I ended up making a wider axle and flipping the axle from under the leafs to over them. I also welded on a set of 'skis' so when I back off the end the trailer will ride down and up the 'skis' without damaging anything.

The fenders are cut from the bottom of a 55 gallon poly drum. The boat slides across them and they act as side guides if needed.

My bunks are simply 1/2" x 4" x 24" chunks of cutting board screwed unto pine 2x4's. My flotation pods aren't supported but the original transom is. I kept the original back roller in place and use it to guide the boat up the centerline of the trailer. The mid roller is gone. I replaced with with a 3/4" x 1" 8" piece of UHMW that acts as a foot stop for my 1/4" x 18" x 6' catwalk so I don't slip off the end while pulling the boat on the trailer by hand. I still have the front and bow rollers and can pull this 600lb hull onto the trailer easily. The big catwalk is just held on with the original U bold that holds the tongue to the trailer frame and where the rear UHMW screws to the cross brace. The side of my hull is 18" off the road like this.

DSC01637_zpsee3825ba.jpg


DSC01632_zpsd5c85120.jpg


DSC01636_zps55499283.jpg


DSC01635_zpsb9cd8ce6.jpg


DSC01633_zps5889b3ea.jpg


DSC01634_zps68cfc8b8.jpg


To splash the trailer I just back off the end of the ramp and the momentum carries the boat away from the trailer. If I'm solo I'll put the bow rope around the winch stand and pull it up on shore when I pull the trailer back out. To get it out I just back until the back of the bunk is wet, then push the boat off and walk out on the trailer. Let the current carry it down stream over the bunks and while using the rear UHWM as a foot rest pull the hull up on the bunks. I'll use the U bolt and front roller as foot rests to pull the boat further unto the trailer. I can almost do it one handed.

If you want I'll try to get some better pictures this evening when we get it wet.
Jamie
 
Finally got off my duff and bought a cover for the boat. Picked up this fellow for $70, it's supposed to be 600 denier but it feel more like 300d. I fit like a shower cap so I invested in $20 worth of 1.5" pvc. I tuend the 'T' fittings in the lathe so the pipe snuggly slips through them. The uprights just slip over the seat posts and I cut another 'T' fitting so it'll sit on the grab rail. I added the angled bar to the trolling motor to give that section a of the cover a peak. It sheds water easily and isn't affected by the wind very much. The boat will be in the shed on the day's I work but sits in the yard when I'm off

https://www.ebay.com/itm/390610535782?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

DSC01663_zps278b0c11.jpg


DSC01664_zpsc7b302e1.jpg


Currently I've washed the hull and plan on painting it once the wet dries. I also want to do some bondo work to the rear and prep that for paint. I have glue for the carpet so maybe next week the kid and I will get to fit that it.
 
Looking good! I have a cover for my boat, but seldom use it, although I should. Not a problem if I park it in the driveway, but in the backyard, I have cedar trees, and they tend to make a horrible mess in the boat. But then again, the boat rarely sits idle for more than a month, so, no need to keep it covered.

Good idea on using the PVC frame for your cover, as the one drawback of a cover is that it tends to hold water to the point that you can't even lift it off the boat because there's so much water in it. The PVC framework will let the water run right off. On that note, I think I'll start using some PVC cross members, rigged in an arch, to keep my boat cover from becoming a swimming pool.

On the note of trailers, I'm about to do a trailer swap for my boat, gonna pick up an aluminum frame trailer tomorrow morning and modify it for my boat. Needs to be 20" narrower, and several feet shorter, and only 1 axle instead of 2. But hey, it's in great shape, and the price is right at just 300 dollars.

Beats the heck out of 1600 dollars for a brand new aluminum trailer for a 16 ft johnboat. Right now, I'm using a galvanized trailer, it's not junkyard material yet, but it has some rusting issues. Still in good enough shape for a re-work, so, I'm trading it out to my buddy that's selling me the aluminum trailer. He re-works trailers and sells them to make a little money, and he ran across this aluminum frame trailer, which turned into a headache for him, due to trying to re-work it to its existing configuration.

But for my purposes, it's going to work just fine. Once the aluminum trailer is done, it'll be the last one I'll need for that boat.
 
Made a solo trip last night as the kid was still at my buddies farm. Without his 180lb self up front the boat really feels like it's floating a lot more at speed and isn't quite as stable when goofing off. Had a great time, went swimming and had a blackhawk fly over at 1.5x tree height following the river.

I've been working on the padding for the carpet. Trying to find a glue that'll work well with the foam floor mats and the carpet. Kind of a PITA but it feels nice when I walk on them and is very quiet.
 

Latest posts

Top