JetJon Conversion - SeaDoo SP into 1236 Fisher

[PSG-1]

It looks cool with the OD green nozzle. Is that zinc chromate primer, or is that paint?

Anyhow, I see you ran into some of the same issues I did with cable travel and set-back. I had to add extension brackets to my pump the first time around. When I re-did the boat with the 4 stroke, I re-did a big part of the pump tunnel, and in the process, I made sure to get the set-back exactly right, now I don't have to use extensions, or modify the cables or brackets. The cable system will work either way, modified or not, as I ran mine like that for about 6 or 7 years, but I like being able to simply replace a part without having to modify it.

 

[painlesstom]

Thanks, I'm set up for powder coating and that is what I did with the nozzle and reverse bucket. Tough stuff that even tolerates salt rather well when done right.

The issue with cable lengths wasn't really too much of an issue. The Seadoo steering cable didn't have to get modified, I just made a longer rod end section. The reverse cable took a few minutes to cut a couple inches off and re-thread, easier to do that then try to figure out how to shorten the pump... The only thing I did to the Yamaha nozzle was to drill another hole for the steering cable to bolt to, this increased the travel of the steering. The Seadoo pump needed some work for the Yamaha steering nozzle to fit over it though, that isn't a part one would typically have wear out and need to replace. Since I'm using the Seadoo hull and pump, with a Yamaha Waveraider nozzle and Yamaha Waverunner trim cable, there wasn't any way to get around modifying it to work as my reverse cable. I probably could have bought one the right size, but it was too easy for me to tweak the one I had. (The Waveraider reverse cable was shot) I did add detents to the handle assembly so it will hold the nozzle just enough to give me neutral. I dubbed this thing FrankenJon for a reason, I've used 4 different skis for parts so far. lol

Can't wait to get it in the water and see how well it all works together. Still lots of work left though...

 

[PSG-1]

Lots of work left, but you've tackled one of the most difficult aspects of it, the installation of the pump. The engine is the second hardest task. Everything beyond that is fairly straight forward, though.

 

[painlesstom]

Personally the Engine and pump have been the easy parts so far. lol It's all the details that eat up the time in figuring out the console and making sure everything is going to work right and last.

I did get some more finished on the console. I reversed the geometry of the reverse control, and added detents where I wanted them, so
Forward - Neutral - Reverse have their own click. Looks very factory, I'm really happy with how it turned out.

Finally got my seat and got it mounted on a hinged based I made, so it will fold forward and away from the deck so I can raise it, or the engine cover.

I got the engine cover started, the basic shape is done that I will build up and level out with some more fiberglass. This is one areas I don't have much experience with so it's been pretty tedious. Luckily it won't be a load bearing item, only a cover, so I'm confident it will work out just fine.

Made up the windshield too, which completed the console. Just need to trim out the back side and it will be finished.

 

[JMichael]

The blue plastic is the shape/mold for the fiberglass engine cover? If it is, isn't the seat going to hit that when you put the seat back in the up position?

Nice looking windshield. I go under too many low limbs to have something like that. LoL

 

[painlesstom]

Thanks, windshield should work nice for where I'll be using it. Plenty of low limbs around here too, but those are the places I take my Mokai.

The seat has 1" clearance to the engine cover, it won't hit it.

This is the initial shell of the cover, I will have better pics in a couple days.

 

[JMichael]

Looking good. How are you venting heat/gases from the engine compartment?

 

[painlesstom]

Thanks. Both sides of the stern where the deck is cut at the angle, the space between the tubing will allow exit ventilation. I will be putting vents on the front panel that closes in the deck area under the seat. There will be twice the airflow allowed, compared to what the jet ski offered.

 

[Mizzie]

Always wanted to do a jet jon but the fiberglass to aluminum bond always worried me... Seems like you got it done! I can't wait to see how this turns out. Subscribed!


-Mike

 

[PSG-1]

Nice looking windshield. I go under too many low limbs to have something like that. LoL

Sometimes, I don't even have to go under limbs. In fact, yesterday, I was running through the marked channel of the flats. It's marked with 3/4 PVC poles. In the "S-curve" of the flats, there's a PVC pole that leans over, and when I made the sharp turn...SMACK! The pipe hit the windshield with a loud bang, but since the glass is lexan, it didn't even leave a mark.

I'm glad there's a windshield there, if that pipe had hit me in the head, it would have definitely gotten my attention. :shock:

 

[PSG-1]

Thanks. Both sides of the stern where the deck is cut at the angle, the space between the tubing will allow exit ventilation. I will be putting vents on the front panel that closes in the deck area under the seat. There will be twice the airflow allowed, compared to what the jet ski offered.

Are you going to put cowling scoops over the top of those vent holes in the transom? If it were me, I'd have one facing forward, and one facing rearward, and build them in a manner that water has to be a couple of inches deep before it will enter those scoops.

Reason being, if you get out on the water and start doing spins or doughnuts, etc, or if you get in rough conditions, or there's a large boat wake, water can come over the transom, and flood the engine compartment.

Having one facing forward will feed fresh air in to the engine compartment, and having the one facing toward the rear will allow some of the heat from the engine to vent out, as the cooler you can run an engine, the better. If you do this, then you don't have to cut any ventilation holes in the front of your cowling. Putting a hole in the front means more noise right behind the operator, something you don't really want. Also, if you line the engine compartment with egg crate foam, it will make a HUGE difference in the sound levels.

 

[painlesstom]

Thanks for the good advice. I'm not too worried about water coming in though. The river I run on is calm and the traffic is very little, many times I won't even see another boat while out. I also have a 800 gph bilge pump on an auto switch in addition to the dual pickups the pump has. The only time I've taken on water from my other boats, was from getting in or getting stuck in a storm.

The egg crate foam is a good idea, and something I will look into when I get it running if feel the noise is going to be an issue.

Update for today.

Made some more progress and things are starting to take shape so all you guys can see what I have been seeing in my head all this time. Engine cover turned out pretty good I thought, for being the first fiberglass part I've ever made. I will say that if I had known how much I was going to end up spending on the materials... well, I would have done something different I think. Wasn't cheap, but it worked out well in the end.

I put a peg on the cover that sits in a hole in the deck to prevent side movement, I also put pins on the back legs of the seat that engage the engine cover so, again, no side movement allowed. I used a rubber hold down fuel tank strap from one of the donor ski's to secure the cover to the deck so it is held when I open the deck. I still have to add some stop cables to each, to limit travel. Getting closer.

Some fuel and oil lines to finish up, and then the electrical stuff. I still have to put together a trailer for it... I'm seeing the light at the end of this tunnel, but it's still a ways off yet.

 

[PSG-1]

VERY nice fiberglass work! Much better than I could do, for sure....LMAO you wouldn't want me doing that. My fiberglass work is mediocre at best.

I can see it coming together now, it's looking good. That's going to be a nice boat when it's done. =D>

As for the egg crate foam, the stuff you really want to use is available from McMaster-Carr. You want the good stuff that's made for this purpose, not the egg crate foam used on bed mattresses.

For enough to line an engine compartment, it will cost you around 80-100 dollars, including shipping. But you do get what you pay for, again, this is an industrial grade foam, the same kind that jet ski manufacturers use to line the engine wells of jet skis. It will last a long time, and not break down like cheaper foam has a tendency to do, especially being embrittled by heat exposure in the engine compartment.

 

[painlesstom]

Thanks, there was an immense amount of commitment and determination involved in that fiberglass. Thought it was never going to be done, finally was, and I can relax for a few now. lol

I've got an account with McMaster too, order from them regularly, so will keep them in mind for the foam. Thanks for the tip.

I hope it runs and handles as well as I'm expecting. Been trying to think everything through as much as possible, I'm sure a few things will need some tweaking. I'm fairly confident it will do what I'm looking for, fuel consumption is one aspect that is a big question mark though. Not sure what to expect. :shock:

Merry Christmas to everyone! :mrgreen:

 

[JMichael]

I've been wondering what it's gonna do fuel wise also. Like what sort of mpg you could get out of it if you baby it along just fast enough to stay up on plane.

 

[PSG-1]

The only way to know about fuel consumption, is to take the GPS on about 10 trips. Vary the throttle from idle, to cruising speed to WOT, try it alone, and then with passengers, try it in swift current/tide vs. no current/tidal movement. Run on some stretches of open-straight water, and then some stretches of winding river and hairpin turns.

Start with a full tank, noting exactly how much it takes to completely fill the tank, then, at the end of a trip, re-fill the tank and make a note of how many gallons it took, then average it out with the GPS track and trip log.

Doing this will give you an AVERAGE fuel consumption rate. For instance, my jetboat gets about 5 MPG, or, burns approx 3 GPH, at average running speeds. With a 22 gallon capacity, theoretically, I could run about 100-110 miles, or run for about 7 hours before refueling. That's the absolute limit, which I'm not going to try.

Because, even with MPG and GPH info, you should always go by the 1/3 rule. 1/3 to go to the destination, 1/3 to return, and 1/3 for reserve. If you operate by this rule, you'll always be on the safe side.

I rarely exceed 60 miles for the total distance traveled on any of my outings, because, first off, that's a pretty long boat ride, and second off, I've run out of gas on the water, and paddling sucks!

 

[painlesstom]

I've got a 9 gallon tank, and the motor I'm using is rated at 5.5 gph at WOT @ 40 mph in the ski (7.2 mpg). I doubt I'd ever take a trip that totaled more than 40 miles. I'm hoping that I can get 10 mpg at a planing speed of 25 mph. That's my goal anyhow, hope it's close to reality. I have a Humminbird 385ci, so GPS is covered.

The 1/3rd rule is good common sense, I don't like to paddle either. Also one of the reasons I mounted the fuel tank where I did, so I can see it. I've even thought about finding a small, air cooled, 2-3 hp outboard as a backup motor in case something mechanical got me stranded.

 

[PSG-1]

You could also plumb in a 3-way fuel valve, and have one of the ports with a QC fitting for a portable fuel tank, for a little extra fuel.

However, if you do this, DO NOT squeeze the primer bulb when it's switched to the portable tank, you run the risk of busting seals of diaphragms in the pump by doing this, as jet ski carbs are a little different than OBM carbs.

To gain prime, you unsnap the QC, and press the ball on the fitting against the QC just enough to open the flow, then pump the bulb until some fuel flows, and then re-connect it.

 

[painlesstom]

Yeah, I'm not a fan of primer bulbs. A good fuel system doesn't need them anyhow.

Holidays, weather, and a few orders slowed progress a little, but I finally got a change to get some more finished. It's down to the little details really. I got the steering stick finished with a start/stop switch and foam handle grip, looks like I bought it somewhere so I'm really happy with that. The lanyard switch and choke got mounted on the front of the deck too.

Framed up a area between the seat and console that will get covered with plywood that will cover the fuel/oil hoses and wiring. I plan on being able to start it again this weekend.

The deck and engine cover needed travel limiting cables. On the deck I ran the cables through pulleys that hook to springs on the transom, this causes them to draw the cables away from hot, or moving, parts when closed.

I also finished bracing the seat base assembly and powder coated it, very solid now.

Getting very close to making a walk around video so everyone can see things in more detail and how it all works together.

Wishing everyone a Happy New Year! :mrgreen:

 

[painlesstom]

Some more finished today.

Transducer mounted and head unit mount installed, I have fishfinder and GPS now. Couldn't go without a cupholder, I even hooked some tubing to the bottom and ran it down to the floor so it couldn't leak on my shelf. Oh, I finished the fuel system and fired it up today too! I love it when things work..

https://www.youtube.com/watch?v=UQeevuvuBl8