Hello MAA,
This is my first post here, although I have been watching for a while. I am thinking of doing a mini build. I had a old 1969 flatbottom riverboat (Richline) Not really a jon its 48 wide but has a 70" beam. I came across a couple ROTAX 582 "Blue top" model 99 65hp motors. Also able to procure 2 four (4) blade "F" blade Powerfin props. 68" I know that this is not as wide as a typical setup but I already had the hull. I am planning on cutting out the transom and redoing it air-boat style. I have a ton of ?'s. I will either be putting poly or gatorglide/linex on the bottom and trying to keep weight low. Will 65hp with a 3 to 1 gearbox reduction with that prop be enough power to push 1 or two people? 20782079208020812082

Heck yes! That Rotax 582 will push that boat and two people easily. (might even be a bit scary in that little boat) I'm running a 582 in my boat and it does just fine. I think you reduction and props will work very well too. There's a ton of information about that motor/prop combination on ultralight aircraft sites. What's the length of the boat? I've never done it, but many feel a jon boat does not make a very good airboat, mainly due the narrow hull and ribbed bottom. Keep us posted! Flathead

Hello ! And welcome to the site...;thumb;...Looks like you're off to a good start with the components...As stated that engine will move you along nicely...

Thanks Flathead and Corky I appreciate the advise and kind words:) I am wanting to make this ito a bowfishing rig. Givin these components, will it run dry ground you think? I cant find much info. From what I can tell this motor with the E gearbox and the right prop can produce 425lb static thrust? Not sure if this is right or not.

Welcome to the site! I'm sure that your powerplant is more than capable of supplying adequate power but I think you might be dissapointed in the long run with your boat. My first airboat was similar to yours but those bottom ribs will negatively affect your manueverability. Also don't expect to run dry without a totally flat boat bottom ... too much drag.

Welcome to the site! I'm sure that your powerplant is more than capable of supplying adequate power but I think you might be dissapointed in the long run with your boat. My first airboat was similar to yours but those bottom ribs will negatively affect your manueverability. Also don't expect to run dry without a totally flat boat bottom ... too much drag.

Thanks aerokirk, I appreciate the info. Do you think if I apply 1/2"
or 3/8" poly between the ribs it would make much difference. (other than weight of course) I am also planning on cutting out the old transome and re-engineering an airboat type shape for added performance outa the prop.

I'm with Aerokirk. I think you'll be disappointed in the long run with that hull. Ya'know, I've often wondered what might happen if someone attached a sheet of poly OVER the ribs thus creating a flat bottom or something close to it....... Anyone ever hear of it being done? AA, I'm NOT suggesting anything.......ha! Flathead

Yes like the others have said it should do fine. It won't slide because of the ribs and you may have to run it a bit harder to keep it on plane because of the narrow planing surface but I'm sure you'll be happy with it. You will probably need to make your cage just a bit wider than your gunnels to clear the prop but it shouldn't be too bad. Maybe two inches on each side

i wouldn't add any more weight, run it the way it is. Keep all your seating low and it should do ok.

Hi and welcome to the site. I'm just looking at your pictures and an idea came to me. You mentioned you are going to cut and rebuild the transom so I'm thinking you have some skills and tools. Do you think it would be much work to remove the ribs from the bottom?? It would then handle like an air-boat. You may have to add some support back to the inside but I'm thinking you may be able to reuse the ribs..... A big part of these boats is the ability to slide and depending on your overall use/ideas, it may be worth your while.

Thank you all for the warm welcome and the great advise. I understand now why the bottom needs to be flat and am going to scrap the idea of trying to retro this hull and build one from scratch. By the time I would take out the transom and add poly,reinforcements,bowfishing deck, seat-engine stand...I think I will be much further ahead if I to listen where others been B 4. Removing the ribbs got me thinking about how much extra work it would be to almost get it right. A huge thank you for the great advise. I will be having many more questions in the weeks ahead. I understand Peirce Aluminum sells kits for aluminum flat bottom hulls. Does anyone know where the best place to purchase a kit near Central WI?(Adams County) Also, I may consider trading that extra 4 blade hub F Powerfin prop and 582 Rotax motor.

I'm in the U.P. of Michigan and I've found that by far the best supplier of my materials has been S.I. Metals in Green Bay, WI. Their prices are far better than anyone up north here. I'm not sure what they carry in aluminum sheeting but they have a good selection of other aluminum stock.

AA

I think you're on the right track there. Heck, I did not even know anyone offered flat bottom hull kits! Based on my limited experience, don't compromise on your hull or power plant. A mini needs all the help it can get! That's the nature of the beast. In addition, if you have a motor and prop to sell/trade, I think you could find a proven hull that would be perfect and still be money/time ahead. Those aviation rotaxs' and props are not cheap! Of course being in Wisconsin you may have to travel a bit, but in the long run it would be time well spent. IMO ......(I'm in Minnesota, so I know) Flathead

Thanks aerokirk for the info, and hello back from a former uper. I actually have an SI about 1hr away, I have purchased in bulk in the past and asked about kits. He said, "I gotta know what I want" (cut sheet) and he would order it. I hear great things about Peirce Aluminum on the Bowfishing Country Forum. Also, thank you for the kind words and encouragement Flathead. Your right, these things can be pricy, the ones I have researched for sale don't have a gearbox / radiator or instruments. I was hoping some kind of a trade/barter deal would materialize. I am in need of a welder upgrade and would like a Miller 350P w/alumapro. If anyone has one willing to barter please get in touch. Here is a pic of what I have to work with. I am in Central Wisconsin and willing to travel a bit for the right deal:)2088