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Celestialsailor · 28-07-2022, 20:39

Incidentally, I was viewing the thread... https://www.cruisersforum.com/forums...sd-267100.html and the op was asking for the best dinghy outboard combination. he was on about the Takacat. I suggested the PB with a 6hp. It was like I farted in the room. Even new out the door with a PB and outboard, you only at 1/2 the price. I guess PB's just aren't trendy enough.

Celestialsailor · 31-07-2022, 00:04

I think I have decided to find a used Tohatsu 3.5hp 4 stroke. All the used 4hp, 2 strokes I see do not have a gearbox. Instead, pull and go. The Tohatsu has a neutral and forward.

skipgundlach · 31-07-2022, 05:22

Miscellany:

I could always talk to Sandy, the original owner, via email and phone. Dunno why others had difficulty. Also have no knowledge of new ownership.

The new folding transom is convenient but horribly inadequate for marine transportation. The original (well, for decades after the double enders) transom with 4 bolts had the beef, particularly if you used different fasteners than factory-provided, and had them hard-fastened. I second the eye bolts; those eyes are great for a lifting bridle, if you want to get it out of the water every night.

The bow cap is merely cosmetic. I never used mine on either of the two I had for 15 years of full-time cruising. I also had no issues towing, other than it wandered around a fair amount; I didn't have it close to the transom, in order to allow it to move without my being concerned for exhaust water entering it.

As to emptying, I found that if you stood in the bow, regardless of how much water was in it, and used an empty jug or OJ square bottle, and scooped toward the bow (see bow cover note!), it would be empty of all but sponge-wipe quantities in a minute for a couple of gallons, or in several minutes for ankle-deep water.

Our 10' bote, with an aged 2-cyle Johnson 6, planed over 400 pounds of payload (engine, fuel, dive gear, two POBs) at 15 knots and sipped at fuel. A 5 mile run to a reef was easy, and we've had it in 6' seas, as well (see previous post about sliding down the face)...

Mike OReilly · 31-07-2022, 08:09

Quote:

Originally Posted by Celestialsailor

I think I have decided to find a used Tohatsu 3.5hp 4 stroke. All the used 4hp, 2 strokes I see do not have a gearbox. Instead, pull and go. The Tohatsu has a neutral and forward.

This is what we have. Has always worked well for us.

rslifkin · 31-07-2022, 11:53

As an interesting note, even though they're not sold as a 5hp in the US, I've seen a kit offered to up-rate those Tohatsu 3.5s to 5hp. It won't spin as big a prop or have as much low rpm torque as the bigger (and heavier) 4/5/6 hp engine, but for a boat that can already plane with the 3.5 it may give more speed or allow planing with a slightly heavier load assuming an appropriate prop is available.

**hpeer** · 31-07-2022, 13:04

Quote:

Originally Posted by Celestialsailor

I'm wondering if the support along the center line was to brace the folding transom. Mine is the solid Genesis version. I think down the road I will add 2 straps on each side at the transom 1/4 fasteners and run them forward to distribute the load further into the hull.

I have not found that necessary.

**hpeer** · 31-07-2022, 13:04

Quote:

Originally Posted by rslifkin

As an interesting note, even though they're not sold as a 5hp in the US, I've seen a kit offered to up-rate those Tohatsu 3.5s to 5hp. It won't spin as big a prop or have as much low rpm torque as the bigger (and heavier) 4/5/6 hp engine, but for a boat that can already plane with the 3.5 it may give more speed or allow planing with a slightly heavier load assuming an appropriate prop is available.

Keeping the bottom clean makes a BIG difference.

Celestialsailor · 31-07-2022, 18:48

https://www.readysetboat.com/tohatsu...propeller.html

Here is the kit. I would imagine it might accelerate the motors life span.

CarlEriksen · 03-08-2022, 00:44

Quote:

Originally Posted by Celestialsailor

https://www.readysetboat.com/tohatsu...propeller.html

Here is the kit. I would imagine it might accelerate the motors life span.

Isn't the 3.5 hp Tohatsu just a differently carbureted 2.5 Hp? If I understand correctly it's just a matter of one running higher rpm. So this mod would run the rpm higher still. Stands to reason that the 2.5 can then be brought to 5 hp was well.

Agree that it would reduce lifespan - if the hp is used. Any engine at sustained higher rpm will last less hours.

While Tohatsu uses the biggest engine at 85cc in this segment, 5hp would be 'aspirational'.

Different topic: I just bought at old double ender 12' PB. I see it has trim tabs built in, I wonder if this will plane? Any inputs on this? I intend to power with a 2.5 Tohatsu upgraded to 3.5 via carburetor.

Celestialsailor · 03-08-2022, 00:48

The double ender trim flats were an attempt to make them plane. I cut mine off the 1st one I had as I only used a 1.2hp to push me around. Found out quick that any head wind over 35 made it impossible to return to the mothership.

Rumrace · 03-08-2022, 06:14

Those cute little moulded in tabs are to help maintain the plane not get up. I have huge hydraulic tabs on an 18’. Down they likely eat up 100hp to get the transom out. When a doe fin is not on the surface it’s robbing power. That’s why they are best suited for underpowered larger boats.

rslifkin · 03-08-2022, 06:35

Quote:

Originally Posted by Rumrace

Those cute little moulded in tabs are to help maintain the plane not get up. I have huge hydraulic tabs on an 18’. Down they likely eat up 100hp to get the transom out. When a doe fin is not on the surface it’s robbing power. That’s why they are best suited for underpowered larger boats.

It also depends a bit on the hull in question and weight distribution. On my boat (38 foot planing hull), moving weight aft and deploying the trim tabs further actually increases speed when running on plane. The extra lift and getting the hull higher out of the water reduces drag more than the extra tab deployment increases it.

So on a dinghy, depending on weight distribution and hull shape, tabs or a foil may add enough lift to be worth the drag and still come out ahead (particularly if it lets you trim the outboard out a bit and not waste as much of your thrust aiming down to lift the stern). Of course, the faster the setup runs, the less likely that compromise is, but at lower planing speeds it's not uncommon.

Celestialsailor · 04-08-2022, 23:08

Quote:

Originally Posted by CarlEriksen

Isn't the 3.5 hp Tohatsu just a differently carbureted 2.5 Hp? If I understand correctly it's just a matter of one running higher rpm. So this mod would run the rpm higher still. Stands to reason that the 2.5 can then be brought to 5 hp was well.

Agree that it would reduce lifespan - if the hp is used. Any engine at sustained higher rpm will last less hours.

While Tohatsu uses the biggest engine at 85cc in this segment, 5hp would be 'aspirational'.

Different topic: I just bought at old double ender 12' PB. I see it has trim tabs built in, I wonder if this will plane? Any inputs on this? I intend to power with a 2.5 Tohatsu upgraded to 3.5 via carburetor.

Yes...I think the 3.5 has a larger bore carburetor than the 2.5. I believe the claimed 5hp is yet a larger carb, still. Regarding the trim tabs on the double ender...your guess is as good as mine. See if you can borrow a small 2.5 or 3.5 to find out.

fox9988 · 11-09-2022, 00:10

I bought a used 12' Porta-bote. Tried it out recently with a 3.3hp Mercury short shaft 2 cycle. 7 knots with 460lbs aboard (including the motor) and a clean bottom. 11 knots with 310lbs aboard. On smooth water. It did the best with the weight shifted forward. Feels like the motor needs trimmed down but the leg is less than an inch from touching the hull, at the bottom. Motor runs great. I have a 3hp Yamaha 2 cycle I'm going to try for comparison. Might run twin engines on it, redundancy would be good. I expected it to run close to twice this fast.?