75hp Long Tail Mud Motor Build

[@jayv7404]

Figured I would put this comment to update anyone who was interested: I made this video after the 2022 summer season, I ran in 1-3 times a week all that season and the 2023 summer season, and it hasn’t skipped a beat- which has shocked me. It turns out the whole time I had an 85” tail shaft on it. I honestly never measured it because it was longer than the last mudskipper long tail I had, which was sold as an 85”, so I just assumed the SPS tail I had was a 100” when in reality it was an 85”. I have since put a 100” tail shaft on it along with a T76 prop and it’s put my top speed on the v hull to 39-40mph. Thanks for all the views and comments!

[@testandoxeon1642]

Search in grabcad for propeller 7.7x16.4 testando xeon. 3d printing and casting in aluminium. Thanks for share your tests.

[@floridawrangler]

“The flat bottom scared me into wearing a life vest”😂 37:19 The adrenaline you get from going 35 on this must be insane Sick motor man🔥

[@hoo_maan8735]

Hell ya brother!!! Dis is what I've been looking around for !!! Stellar build!!

[@MudMotorsMax]

love it brother! this could be huge! i think we need to build you a special HDPE long tail boat for your big power long tail! maybe a Vietnamese Vo Lai or a Thai racing Sampan. we can talk about it sometime for sure. I'll be building boats real soon! Good work keep it up

[@jayv7404]

Thank you! That would be a super cool boat for sure. Something like that I would probably break 50mph with. Also I’m digging your canoe with a long tail. My neighbor has a 28hp single cylinder two stroke engine rated for 16000 rpm I’ve thought about mating to a longtail on a boat like that.

[@MudMotorsMax]

@@jayv7404 I have seen Vietnamese vo lai around 50 miles an hour with 15 horsepower I'm certain you will haul more ass then what's comfortable 😂 keep it up. Yeah that scanoe works well it's just about thinned out on the bottom

[@bricehale6593]

Thats sick man flying down the river I have a 16' marsh hawk with a small home made mud motor its way under power and the tail is only like 41" long so it just wants to lift the rear end up instead of drive the boat forward it goes like 6mph 😂 im not sure what I'm gonna do about it

[@jayv7404]

That’s sweet, definitely gonna need a longer tail tho. Even the short American tails are at least 60”. It’s either that or drop your transom way down

[@azlongtales]

Nice job man!!! Super kool!!!!! Screaming!!!!!

[@jayv7404]

Thank you sir!

[@jumper5029]

I was thinking off this same thing, also thinking of using small ultralight air cooled engine

[@durbeshpatel3047]

That is cool as hell

[@louismoore3314]

Third time watching this. So sick. You should put out a “update” video.

[@jayv7404]

Glad you’ve enjoyed it! I honestly don’t have too much of an update on it. I might do a shirt video on it. I put a different prop and a longer tail shaft on it and got it to 39-40mph and handling smoother, but I ran I’ve run it for two summer seasons 1-3 times a week and it’s still going strong- which has shocked me.

[@louismoore3314]

@@jayv7404 I see, can’t fix what ain’t broke. Damn 40 is insane though! That is pretty impressive how reliable you were able to make it. Sweeet!

[@justinherdman87]

this is exactly what i been trying too gather up parts and build.. i was thinking a 300cc single? or w.e small dki' 2 stroke on a longtial.. or even and old 1 luger snowmobile 340? w.e... If not i mite just try build a jet jon.. nice build though.. awesome..

[@jayv7404]

To be honest with you, I’d do a jet jon unless you’re going to be putting it on a small boat. This was fun to build and all, but a jet jon would be much easier to drive.

[@PappyfromtheKeys]

Great video! Fun to watch an alternative power system like this. The Thai guys and gals have this so well dialed in. Looks like you shot this around Old Town on the Suwanee? Saw the RR bridge. One of my favorite places and rivers to run. Merry Christmas by the way!

[@SCFunSeniors]

AWESOME video, Jay, very informative. I'm also interested in building one myself. Thanks G

[@testandoxeon1642]

Hi, I calculated prop to 600 lbs, 73 hp, 6300 rpm and results 7.7x16.4 inches prop. Try to found in grabcad.

[@testandoxeon1642]

Hi, you can use a turbo charger amr300 to increase the power. I will try to share another prop 7.835x16.4.

[@galpaoalr5047]

Use a 3 blade semi surface drive tai style prop . It will go like a rocket

[@jayv7404]

I’ve always been told a 3 blade prop is slower. I see a bunch of surface drive guys switching to 2 blade props

[@volvo245]

The CC couldn't really make out what you were saying but when you ran it at full throttle it told me the sound was "music".

[@dealerssoffers]

Careful with that battery right next to the gastank.

[@kovenant7]

Thanks!

[@roblacitinola866]

Jeff Spicoli? Nice build bud-

[@rootwad]

YEE, and folks i can NOT stress this enough, HAW!

[@davidheitman7004]

wild!

[@luizroberto6915]

Hi, try to use a racing prop 8.375x11 and tell us the results.

[@jayv7404]

@@luizroberto6915 Unfortunately, I can’t find a prop with that pitch that will fit a standard long tail taper.

[@luizroberto6915]

@@jayv7404 Hi, can you tell a max rpm engine with load( for example, your engine spins 6300 unload, but with load can decrease to 5750) and total weight (pilot+boat+long tail+tank+fuel) and diameter long tail shaft and if a conical shaft as 5/8 but a tip shaft is 1/2 or 1/2 and tip 3/8? I will try to draw a specific prop and leave in grabcad. You can 3d printing and casting in aluminium. Thanks.

[@fredsbbq1975]

Jay thanks for sharing. I am slapping a 701 yamaha jetski engine in my long tail mud buddy . What did you use for a water pump?

[@jayv7404]

I covered that in the video. This is the one I used: www.tractorsupply.com/tsc/product/hypro-4-roller-cast-iron-sprayer-pump

[@fredsbbq1975]

Did you hook up the pump outlet hose to the water hose connection blow out on the jetski motor?

[@fredsbbq1975]

What do you think about this electric water pump 7971-111Y-SB

[@rumaltagracia7843]

Nice 👍🏽

[@ocracokelongtail]

Good job! Answered a lot of questions I had about that type of build. I considered it, but I like the air-cooled because they don't suck in mud/grass. A "keel cooler" like the Thais use might solve this though, and you already have the water pump, so you are not that far off from having one. Did you already have the jetski?

[@jayv7404]

Thank you! Air cooled is definitely better. I don’t hunt or go places that are super shallow so I’ve been fine. My next build will have an air cooled or internal cooling system engine… less to worry about Yup, already had the jetski. Traded a go kart for it and the trailer, then sold the trailer.

[@ocracokelongtail]

My channel explains my remote steering rig for a Harbor Freight 670cc. I have since added a twist grip throttle on the horizontal stick. I need some speed for fishing, but too much and I couldn't handle the thing well.

[@ocracokelongtail]

@@jayv7404 I was looking at your trim tabs and got to thinking about putting cooler pipes below a larger one in the middle of the stern. Seems I might need about 25ft of copper 1" for 40 hp. The Thais attach boards to the keel, but my bottom is flat, so I don't have one. I operate on a lot of skinny water here with grass & mud, so much that I've pretty much given up on the expensive jet drives. Any thoughts?

[@jayv7404]

@@ocracokelongtail So your thought is basically to make one large trim tab and mount a keel cooler in that?

[@ocracokelongtail]

@@jayv7404 Sort-of. My boat is 56" wide at the bottom of the transom, so I already have a heafty 12" Vance setback plate to give the proper ratio for a 100" shaft. The keel cooler rig would be mostly attached to that, with the trim tab closing the gap. I use the Beaver Dam large longtail kit. Plan is to take the intake off my last working 40hp outboard jet and attach the longtail there. (Really..?) There is a garden hose input to the water pump but don't really know how to get to the water output. Aw well, most of my ideas don't work, but sometimes they do!

[@lylehunter881]

Just find a prop shop an have them work it to a 9 or 10 pitch

[@patrickpuma]

25:40 25:57 38:57 41:50

[@yyaksok5039]

good content ! ;)

[@coltensawyer6761]

Just curios it’s a 14-34 what was the weight of that setup you made generally? I’m gonna try a 670 Longtail maybe on my 14-36 just comparing you know. How did the boat take the weight in the flat bottom one ? I saw you had ht on a v as well.

[@jayv7404]

The whole motor and tail set up weighs probably 170-200lbs. It took 3 people to transfer it from the flat bottom to the v hull. You’ll be fine with a 670 long tail. As long as you have good wood on your transom and put some transom braces (I think I showed the ones I did in the video), it will support it no problem. The transom braces are just some pieces of angle aluminum or steel and some self tapper screws. Both boats handle the motor fine, but I didn’t have the braces on the flat bottom and it would bend the transom in and out about 1.5”.

[@coltensawyer6761]

@@jayv7404 my boat has two knee braces in the floor and I’m gonna weld up a steel brace system and rivet it to the top. And I’m doing a aluminum transom right now. I think it will be solid. Did that motor swamp your boat ?

[@jayv7404]

@@coltensawyer6761 What do you mean? Did a bunch of water come over the back?

[@coltensawyer6761]

@@jayv7404 yeah when you come off plane fast. The water come up and over the back. On the flat bottom. And my transom has two floor braces already and I’m doing a 1,5 thick aluminum one along with plate on the outside. And then some kind of support system. Should handle it and not move any.

[@jayv7404]

@@coltensawyer6761 On the flat bottom yes, water would come over the back of the boat under sudden slow downs, but not a ton. V hull doesn’t do it. Definitely have a bilge in the back of your boat.