For you guys that have them and for those that have built them .

For the builders, is there a formula or general rule on length of shaft / length of boat ?

For the users, are the mud motors typically better or worse on fuel than a conventional two cycle motor ?

I just built one with a long tail. I ordered the 80-inch shaft and found out later I should have gotten the 100-inch shft. It has something to do with the height of the transom so must be an angle thing. It runs fine, but I would advise a prop guard and an extra prop. I hit something in the mud and broke the prop. An easy fix with an extra prop long and hard trip back with only push poles.

What boat did you put that 80” on Larry ?

I run a 60in shaft on a 14x36 alumacraft Jon. 6.5hp predator motor. The longer the shaft the easier on the operator. Mine works great but I'm standing on the back bench while operating and an hr long run will wear me out. I run a 7in prop to make up for the steeper angle of shaft. 2 men an fishing gear on flat water will do 14mph. It's a beaverdammudmotor kit. Been very happy with it. Fuel consumption is awesome. Way less fuel than a 2stroke

I was thinking that the fuel consumption would be less but didn’t know if it would be enough to talk about . Flint with that 60” shaft, is the operator staying dry ?

Never had any troubles getting wet.

this is a subject that interests me greatly! I want to build one so bad I can taste it but . Not sure on hp and prop sizing. All I know is pitch of prop can either produce strong torque or speed. personally id rather have torque. This would go on a 16 72 flat bottom john

I'm no mud motor guru just got one for fun an fishing. I run aluminum props that are cheap I order from the same outfit that made the kit. If I hit something hard enough to break it I just slap another on and go. Takes about 2 min. Tony on a boat that size I'd imagine your wallet is the main deciding factor. I'd guess at least a 16hp and would run a ss prop. Them bigger mud motor ss props are pricey though.

I bought a smallish aluminum v boat , with plans of finding about a 3 to 6 hp motor. But our creeks are so low right now that I wouldn’t dare run a conventional motor for fear of plugging the cooling system with mud . I have no doubts that our creeks will fill back up by trapping season, but they don’t have to ! I would hate to miss out on a high dollar coon season for a lack of equipment, so my plan to stay mobile is to go with the mud motor. A drought year like this one could happen any year .

I d think a mud motor for chasing beaver and rats in slews would be the cats meow! Thanks alex I was considering no less then a 12 hrs I have a nice selection of props my deceased step father was a boat mechanic! I believe im mechanically inclined enough to build one from scratch !Like any thing id research it for days before I jumped.

Cool!

I run a go devil with a 23 hp Briggs and Stratton on a 16' Polar Kraft and it is very easy on gas

I have a 24 horse v twin go devil. It uses more fuel that the 15 horse 4 stroke I had on the 16’ aluminum boat prior to it.

I have a friend who builds everything. He can machine parts etc. Several years ago he looked into building a mud motor. At the time he had a 20hp Honda beaver tail mud motor. I had a 23hp Briggs Go Devil and a 16hp Briggs Go Devil. He took measurements from all of them, messed around with endless research and parts lists. He finally landed on a medium kit from SPS Swamp Runner. He said there was no way to come close to $$ building it on his own. Actually he is now a SPS dealer and puts kits together for people who don't want to mess with it. He has sold a lot, lot, lot of them with no trouble. lol

I live on the river and he occasionally has customers test drive SPS's out here. We have also tested many of their prototype motors. I have owned, driven or been in almost every long tail out there over the last 20+ years. From the small boat Golf ball mentioned and where it will be used, I would strongly recommend the small SPS kit with a 6.5hp Predator motor. One person can pull the shaft off in seconds and carry motor up & down steep banks in two pieces. Often when trapping, with the SPS's in various sizes I own, I pull the shaft off and bring it in shop or tent overnight to keep grease warm so pull starting is real easy in am. I have also loosened the shaft and pulled it out far enough to disengage, then start and warm up motor on real cold mornings. Turn off motor, re engage shaft and re start motor, your on your way. Props are cheap and can be replaced in under 5 min. I used to run an 8" prop up stream checking traps, then swap to the 8 1/2" or 9" back down stream with my medium kit, just to get a little more out of her. Many years I can go all season on the same prop, other times I'll break one the first week. I have never used more than 3 in one season.

Few main things are:

1. Always wear kill switch tether and life jacket with mud motors. Make sure dogs and onlookers, or anything else you don't want chopped up are clear from prop area b4 starting. I don't like to take my eye off running prop when people or dogs are around.

1. Balance boat front to back and side to side. You do not want to run with bow up and transom down like a traditional outboard. I like to have a seat I can move a bit forward or back, the rear fixed seat in most boats is to far back and to low for long tail motors imo. I often send my dog forward or back while cruising to keep the boat in the "Sweet Spot". I also will move a Beaver, couple Coons, gas can etc, here or there to balance to Sweet Spot" while cruising. Makes a huge difference. The smaller the boat the more important this is. You will feel it when you get it right.

2. Keep prop in middle of wake. When cruising, prop should be in center of wake. Adjust, by bending skigg (fin below prop) after balancing boat, to keep prop in highest part of wake wash while cruising.

3. Run the boat for several days or weeks b4 taking it out for work. There is a bit of a learning curve and you don't want to be messing with that while running traps or set lines. Do not turn real sharp at high speed until you get used to it. There is increased leverage on handle while turning.

Good Luck and be safe out there!

thanks trapset ill have to check into those the ones I looked at was 7g with a 35 hrs but those were surface drive models

Surface drives are awesome If you don't mind trailering your boat. Way more price wise but are easier to run and more compact. I is a poor boy probably won't ever have one of them

I have no experience with surface drives. I have heard they work better with soft bottoms rather than hard sand or rock bottoms. But, less of a learning curve because they handle more like an outboard than long tails do.

I keep a trigger start propane torch in an ammo box in the boat for quick start on a fire if needed in an emergency but also for warming the shaft on very cold days prior to firing up the engine.

Not trying to be a smart butt here but do you guys still have open water when it gets that cold ? Around here if it gets cold enough to have trouble starting a four cycle you will need something to run on top the creek .

Its the grease in the long shaft that gets real hard overnight making it hard to turn over fast enough by hand to start easily. The small motors don't come with electric start. The currant keeps thew water open in temps well below freezing.