Little Jon Build

[Still Afloat]

So I bought a new Lowe 1448M about a year ago with the intent of building a small jet Jon. Between work, life, working on the house, mowing ten acres, etc, etc it’s taken a year to get started on this project. In the meantime the gears in the head have been turning and I think there is a reasonable design floating around in the cobwebs between my ears. I don’t claim be an expert by any means. If anyone is interested feel free to follow along. I’m a few weekends into the build and I’ll post updates as time allows.

I did a few test runs last year with the bare hull and three different outboards.

The first was a tiller F25 EFI Jet. It’s a 200 pound beast and boat was dangerously tail heavy. I managed to get in some test runs without crashing or sinking and it was apparent that the weight (batteries, fuel, etc.) needed to be as far forward as practical. That led me to some estimated center of bouyancy and center of balance calculations. It wasn’t working out so I tossed pods into the equation and it seemed feasible at that point.

The second outboard was a Suzuki 9.9 that’s been modified to a 20hp. That’s a great pairing with this 14’ bare hull. It’s still light agile and it would quickly launch out of the hole and top out at about 27 mph at wot. If I didn’t want a bow mount trolling motor and the batteries that go with it I would have just stopped right there. (Maybe later I’ll wish that I would have stopped there.) I’m interested to see how this motor performs with the fully rigged out boat. Unfortunately, this snappy little motor will likely spend most of its life as a kicker on my bigger boat. What a shame.

The third motor that I tried is a Suzuki 25 EFI. It was propped too low and things got busy with summer projects and I never came back to it but, it was still pushing the bare hull around at 27mph at 1800 to 2000 rpm short. Weight wise, this motor is around 175 pound so it’s between the heavy Merc and the 100 pound 9.9/20. The Zuki 25 is the only one of the three outboards that has power tilt/trim. Ideally, I want to be able to swap between the Zuki 25 and Merc Jet with minimal changes in balance and trim.

Anyway this intro is dragging too long so we’ll get into the build.

The plan is a lower deck and an upper casting deck that will cover the batteries, fuel, etc. All aluminum, no stinking wood on this boat!
That box and hard hat on the toolbox is a dummy passenger. I’ll probably fish this boat alone most of the time but, you never know.



The seat pedestal on the 2x4s is telescopic. It will extend to a comfortable seated position or squat down to out of the way or allow a passenger to ride up front at speed with a lower center of gravity. The. actual upper deck is about six inches lower than the temp seat placement.

 

[Still Afloat]

In this post I’m laying out the supports for the lower deck. The channel over the ribs is 2 x 1” and the side supports are 1.5 x 2” unequal leg 90 degree. Everything is .125” thick 6061 or 6063. I wanted to go thinner but, this what’s available locally.

 

[Still Afloat]

Now to try out the Miller 211 and Spoolmate 150 that picked up last year.

 

[Still Afloat]

Here are some of my first aluminum MIG welds. Nothing to brag about but, it will work. It’s basically the same steel MIG except it’s faster and your are pushing instead of pulling. The Spoolmate is really bulky compared to a MIG torch. I might try some .035 wire the regular MIG torch for the tight spots.



The second and third photos are gussets that I added to the end of the angle that will support the upper deck. Probably not necessary but, worth the peace of mind.

 

[Still Afloat]

I did run into one glitch. The ribs that I had intended to follow to upper deck were not symmetrical. In fact the entire hull has a significant twist. If I would have caught this last year I would have returned the boat. I guess this is just post covid quality control.

Anyway, I had to remove one of the supports so the vertical transition to the upper deck could be pushed back a few inches. This had the side benefit of allowing more space for a “real” gas tank not the huge space wasting plastic portable.

I got most of it with the sawzaw. No room for the grinder and cutting wheel either. The last bit was the hard way.



Here’s the 5 gallon tank that I ordered. I’ll weld handles on it call it portable in case anyone gives me grief about it.

 

[Still Afloat]

This weekend is the fuel/battery tray if the miter saw that I ordered from Home Depot arrives. It was supposed to get here on Tuesday but, now it arrives (maybe) on Sunday. Thanks a lot Homer.

Stand by.

 

[Ray Clark]

Cool! Thanks for taking us along.

 

[Stand Up]

Very interesting. I'll stay tuned to this channel.

 

[FuzzyGrub]

Lots of progress in a short time. Spring approaching quickly, is a good motivator.

The following are just my suggestions for you to think about, from my years of experience, and use. Finding out what I liked, what I didn't.

If the aluminum across the bow, is to represent the end of the casting deck, I'd move the casting seat back further. Gives you more room with the bow mounted trolling motor that will be there. Fishing rods and tackle, and maybe electronics, it will get crowded fast. The seat will also help getting up onto the casting deck. It is a big step. It also forces you to walk around it, and sometimes that far forward can be a little tippy.

I didn't like using mushroom or big base seats on the casting deck. They become perminent and you evventually find for some uses, being able to remoe is an advantage, The pin style I liked better for up on the deck. Maybe use that one for your passenger seat.

The jet and prop motors will havve different mounting heights for ideal performance of each. Some type of jack plate is probably going to be needed. I wouldn't go crazy with a hydraulic one, but a manual one like you see on Outboard Jets, might be good. I think, over time, you will prefer one to other, and will stick to that. Swapping motors, even if only twice a year, will get old. Especially the heavy jet. That will probably come down to how good the fishing is, where only the je can get you to.

This is probably too late, but couldn't tell how much of the floor framing is already welded to the ribs s mocked up. While all aluminum, the framing and the floor will still add up weight wise. Weight, een if distributed, is the enemy of the jet. On my 1648, I fretted for a long time about haing a level floor vs one that followed the slight angle of the mod-V. I ended up just filling the gap between ribs with foam and a sheet aluminum top. It worked out very well, and the slight angle hasn't bothered me at all, with years of fishing from it. Now, some of that decission was based on having to bolt, screw, or rivet the frame and floor vs welding, which it is a skill and equipment I don't have.

Anyway, nice project and I will be following along.

 

[Billy H]

Lots of progress in a short time. Spring approaching quickly, is a good motivator.

The following are just my suggestions for you to think about, from my years of experience, and use. Finding out what I liked, what I didn't.

If the aluminum across the bow, is to represent the end of the casting deck, I'd move the casting seat back further. Gives you more room with the bow mounted trolling motor that will be there. Fishing rods and tackle, and maybe electronics, it will get crowded fast. The seat will also help getting up onto the casting deck. It is a big step. It also forces you to walk around it, and sometimes that far forward can be a little tippy.

I didn't like using mushroom or big base seats on the casting deck. They become perminent and you evventually find for some uses, being able to remoe is an advantage, The pin style I liked better for up on the deck. Maybe use that one for your passenger seat.

The jet and prop motors will havve different mounting heights for ideal performance of each. Some type of jack plate is probably going to be needed. I wouldn't go crazy with a hydraulic one, but a manual one like you see on Outboard Jets, might be good. I think, over time, you will prefer one to other, and will stick to that. Swapping motors, even if only twice a year, will get old. Especially the heavy jet. That will probably come down to how good the fishing is, where only the je can get you to.

This is probably too late, but couldn't tell how much of the floor framing is already welded to the ribs s mocked up. While all aluminum, the framing and the floor will still add up weight wise. Weight, een if distributed, is the enemy of the jet. On my 1648, I fretted for a long time about haing a level floor vs one that followed the slight angle of the mod-V. I ended up just filling the gap between ribs with foam and a sheet aluminum top. It worked out very well, and the slight angle hasn't bothered me at all, with years of fishing from it. Now, some of that decission was based on having to bolt, screw, or rivet the frame and floor vs welding, which it is a skill and equipment I don't have.

Anyway, nice project and I will be following along.

Good stuff. In my latest Jon boat I also just filled between the ribs with foam and cover that. Bought some 3/8 thick rubber flooring like is in a gym and just have it laying on top. Works out well for my purpoises. Not very heavy, Easy to work with, does not need to be fastened, won’t slide around, Can be removed in minutes if need be for hosing off or getting to the hull.

 

[airshot]

When you mentioned jet....I thought you mean't you were installing a jetski engine....it would get that excess weight off the transom.......and it would fly !!

 

[thill]

Looking really good.

If you want to use the mig torch, swap the tip for a .040 tip when using .035 wire so it feeds smoothly. Your welds look good. It looks like you have it figured out.

Keep up the good work!

 

[Still Afloat]

Lots of progress in a short time. Spring approaching quickly, is a good motivator.

The following are just my suggestions for you to think about, from my years of experience, and use. Finding out what I liked, what I didn't.

If the aluminum across the bow, is to represent the end of the casting deck, I'd move the casting seat back further. Gives you more room with the bow mounted trolling motor that will be there. Fishing rods and tackle, and maybe electronics, it will get crowded fast. The seat will also help getting up onto the casting deck. It is a big step. It also forces you to walk around it, and sometimes that far forward can be a little tippy.

I didn't like using mushroom or big base seats on the casting deck. They become perminent and you evventually find for some uses, being able to remoe is an advantage, The pin style I liked better for up on the deck. Maybe use that one for your passenger seat.

The jet and prop motors will havve different mounting heights for ideal performance of each. Some type of jack plate is probably going to be needed. I wouldn't go crazy with a hydraulic one, but a manual one like you see on Outboard Jets, might be good. I think, over time, you will prefer one to other, and will stick to that. Swapping motors, even if only twice a year, will get old. Especially the heavy jet. That will probably come down to how good the fishing is, where only the je can get you to.

This is probably too late, but couldn't tell how much of the floor framing is already welded to the ribs s mocked up. While all aluminum, the framing and the floor will still add up weight wise. Weight, een if distributed, is the enemy of the jet. On my 1648, I fretted for a long time about haing a level floor vs one that followed the slight angle of the mod-V. I ended up just filling the gap between ribs with foam and a sheet aluminum top. It worked out very well, and the slight angle hasn't bothered me at all, with years of fishing from it. Now, some of that decission was based on having to bolt, screw, or rivet the frame and floor vs welding, which it is a skill and equipment I don't have.

Anyway, nice project and I will be following along.

All good points and well taken. I’d don’t care for the mushroom base either and I might still go with the flush mount plug-in base. I have a bunch of plug-in type Springfield base and parts in stock from other boat projects. As far as the position, it’s as far back as possible due the access hatch for the battery and fuel tank compartment. I also want a front compartment with two hatches, one on each side of the seat post. It’s only a 14’ boat so there will be some compromises.

I’m considering a Jack plate for you reasons and also to minimize holes in the transom due to different mounting patterns.

I hear you that weight is the enemy of a jet boat and I’ve been thinking the same thing. The aluminum is no heavier than plywood and wood framing but, you really don’t need all this stuff to get from one steelhead hole to another. It can be lightened up by pulling out the batteries a removing the Minnkota when using as a jet on the rivers. If the jet doesn’t pan out for this boat it’s not a big deal. It will be fun it does but, I’m not going to get hung up on that. In the back of my head there’s an itch for a larger 90/60 or 60/40 jet boat anyway.

As far swapping motors the steelhead are seasonal so it’s an October through January thing for the jet. These are tiller motors and I have a hoist so maybe an hour at the most. Anyway, this is a secondary boat that’s mostly for winter and spring.

Thanks for the suggestions.

 

[Still Afloat]

When you mentioned jet....I thought you mean't you were installing a jetski engine....it would get that excess weight off the transom.......and it would fly !!

I would have bought an old beater if I was going to do that.

When you mentioned jet....I thought you mean't you were installing a jetski engine....it would get that excess weight off the transom.......and it would fly !!

There are some crazy fast conversions out there.

 

[Still Afloat]

Looking really good.

If you want to use the mig torch, swap the tip for a .040 tip when using .035 wire so it feeds smoothly. Your welds look good. It looks like you have it figured out.

Keep up the good work!

Good point. I’ve got an unused MiG torch that came with the 211. The guy at Airgas said it will work if you keep the feeder hose straight.

 

[FuzzyGrub]

Good stuff. In my latest Jon boat I also just filled between the ribs with foam and cover that. Bought some 3/8 thick rubber flooring like is in a gym and just have it laying on top. Works out well for my purpoises. Not very heavy, Easy to work with, does not need to be fastened, won’t slide around, Can be removed in minutes if need be for hosing off or getting to the hull.

I went 16ga aluminum sheet, 1/2" fatigue mat, with a rubber ribbed top to protect it. The shallow V helps with rain water draining to the back bilge. It did make for a littl extra work for the centered mounted passenger seat.

 

[FuzzyGrub]

All good points and well taken. I’d don’t care for the mushroom base either and I might still go with the flush mount plug-in base. I have a bunch of plug-in type Springfield base and parts in stock from other boat projects. As far as the position, it’s as far back as possible due the access hatch for the battery and fuel tank compartment. I also want a front compartment with two hatches, one on each side of the seat post. It’s only a 14’ boat so there will be some compromises.

I’m considering a Jack plate for you reasons and also to minimize holes in the transom due to different mounting patterns.

I hear you that weight is the enemy of a jet boat and I’ve been thinking the same thing. The aluminum is no heavier than plywood and wood framing but, you really don’t need all this stuff to get from one steelhead hole to another. It can be lightened up by pulling out the batteries a removing the Minnkota when using as a jet on the rivers. If the jet doesn’t pan out for this boat it’s not a big deal. It will be fun it does but, I’m not going to get hung up on that. In the back of my head there’s an itch for a larger 90/60 or 60/40 jet boat anyway.

As far swapping motors the steelhead are seasonal so it’s an October through January thing for the jet. These are tiller motors and I have a hoist so maybe an hour at the most. Anyway, this is a secondary boat that’s mostly for winter and spring.

Thanks for the suggestions.

The hoist will certainly make the motor switching easier. I've also seen people switch out the jet foot for prop. They said once they did it a couple times, could do it in an hour. I use to pull the Alpha II drivve every winter and put back in the spring. After a couple of times, it was just work.

BTW, those itches, you tend to scratch, eventually.

I can't wait to see it christianed with its first fish slime.

 

[Billy H]

The hoist will certainly make the motor switching easier. I've also seen people switch out the jet foot for prop. They said once they did it a couple times, could do it in an hour. I use to pull the Alpha II drivve every winter and put back in the spring. After a couple of times, it was just work.

BTW, those itches, you tend to scratch, eventually.

I can't wait to see it christianed with its first fish slime.

Good friend of mine does the switch from prop to jet on his 115 Yamaha. He can about do it blindfolded now. A little invested up front but he’s got the best of both worlds for lake or skinny water river

 

[Still Afloat]

I’ve seen a few jet Jon’s advertised on Facebook that have both lower units. The other thing to consider is that many Jon boats rated for 60hp have 90/60 jets. It would be a real screamer with a prop lower unit. Anyway, that’s another day and another project. We’ll see how this works out.

I heard yesterday that from my neighbor that the ice is off many off the lakes already. As soon this decking is in the little Jon I’ll take it for a test run with each motor again. That’ reminds me that I’d better get on prop on order for the Zuki 25hp.

 

[Crazyboat]

When you mentioned jet....I thought you mean't you were installing a jetski engine....it would get that excess weight off the transom.......and it would fly !!

That's exactly what I was thinking.