260RIB outboard, 8hp?

[dbsea]

Has anyone else put an 8hp 2-stroke on your 260RIB? I have a 2020 Tohatsu 6hp 4 stroke and I can’t get the dinghy up to speed and on plane with two people onboard. My logic is that the 8hp 2 stroke weighs the same as the 6hp 4 stroke but has 2 cylinders/ more torque. The dinghy is rated to 66lbs or 6hp for the motor, but the 8hp actually weighs 57lbs, less than the 6hp 4 stroke. Finding an 8hp 2 stroke in good condition is another challenge altogether. 🙂

 

[dgiles]

If a reasonable amount of weight is near the front, they will plane with 2 reasonable weighted adults with a 8hp as long as it is propped right. I dropped a couple inches of pitch for more low end and it makes an amazing amount of difference.

 

[dbsea]

Thank you. I’m going to get a reduced pitch prop for my 6hp and see what that does. Good to have a backup anyhow. If that doesn’t work I’ll look for a 2 stroke 8hp!

 

[BB marine]

I had a Gala 270 aluminum Rib that weighed 110lbs 8'10". I believe the 260 is 8'6". I have a 6Hp Suzuki 54lbs that would just get it on plane with one person on board. 2 adult passengers no way! I purchase and repair older small fishing motors and sell as a hobby. 1.5hp to 15 hp 2 strokes. I tried 6 hp Evinrude 60 lbs, 6 hp Mercury 75lbs, 7.5 Evinrude 60lbs all 2 strokes. 1 passenger plane 2 passengers would never break full plane. I tried a 9.9 Mercury 2 stroke 75 lbs and a 15 hp Mariner 75lbs both Engines turned the Gala 270 from a tender to a fun little boat. The 15 and 9.9 are the same engine, difference being timing and carburetor, weigh the same and I really did not see a noticeable difference in performance. Using my iPhone and MPH app, 1 passenger 26mph (me in the boat) 2 passengers My wife and I in the boat 23mph. It jumped on plane instantly!!! All the smaller engines, 6 to 7.5 hp, 1 person on plane average speed WOT 11 mph and it took some time to do it! 2 passengers 6mph WOT. I used the Mariner 15hp for a season, I changed the model decals to a 9.9. The rated HP for the Gala 270 is 10 HP. I would have used the 9.9 but I sold it. It was fun season using the boat with this engine. We did a couple of long runs on Lake Michigan, 20+ miles on a calm day and cruised around the islands on Georgian Bay filling a cooler and actually cruising faster than my Cutwater would cruise . I installed a lifting davit because the 75 lbs was more than I wanted to handle on a regular basis especially when an anchorage was a bit rough. I sold the Mariner and use the 6Hp Suzuki. I can handle it without the davit and except going 4 to 5 mph. If you don't mind picking up a few extra pounds and want a fun little boat to play around in pick up a 9.9, 2 stroke.

 

[dbsea]

Thanks Brian. The 260 is only rated to 6hp, 66lbs. Wouldn’t the 9.9 be way too heavy?

 

[FlyMeAway]

Your best bet is to fit a planing fin (Davis makes one), finagled to fit your engine. You can likely get these installed by a local outboard shop or you can DYI. Even professionally installed it'll be 1/10th or 1/20th or so the price of a new motor (especially a 2-stroke which in decent shape can carry a premium, sometimes more than a new 4 stroke for a 10+ year old engine).

The planing fin will solve this problem pretty much guaranteed.

The other possible option is a tiller extension and sitting amidships in the dinghy, with your passenger all the way up front. This can work too but is a bit more YMMV.

 

[dbsea]

Your best bet is to fit a planing fin (Davis makes one), finagled to fit your engine. You can likely get these installed by a local outboard shop or you can DYI. Even professionally installed it'll be 1/10th or 1/20th or so the price of a new motor (especially a 2-stroke which in decent shape can carry a premium, sometimes more than a new 4 stroke for a 10+ year old engine).

The planing fin will solve this problem pretty much guaranteed.

The other possible option is a tiller extension and sitting amidships in the dinghy, with your passenger all the way up front. This can work too but is a bit more YMMV.

Thanks for the suggestions, they are so great I already did them! :-D I used the Davis fins, and I have a tiller extension. I'm hoping the reduced pitch prop is the missing part of the formula! If not, i'll settle with what I have until I can get a whole new setup down the road. 🙂

 

[FlyMeAway]

Thanks for the suggestions, they are so great I already did them! :-D I used the Davis fins, and I have a tiller extension. I'm hoping the reduced pitch prop is the missing part of the formula! If not, i'll settle with what I have until I can get a whole new setup down the road. 🙂

I do wonder if this means the Davis fins aren't installed optimally. I have not done them with the current dinghy setup but I've helped friends do this install and have done it on prior boats. We even got a smaller motor to push a similar sized RIB on a plane with the Davis fins!

Let me know the prop pitch exploration, though. That's an easy fix. I haven't gotten a lot of dinghy use in the the Tug so far but likely will do more this summer. It's easier with a 3 /o than a 2 y/o... I think?

 

[dbsea]

I’ll report back for sure. I should note that I can plane with just me, and go along at a nice clip. I am 6’5” and 210lbs tho. Add another modestly sized human and I can’t make it work. 🙂

 

[Red Raven]

I tried a lower pitch/size prop on my 6hp and it didn’t work. I thInk I must have been running into an rpm limit. At max rpm it began to cut out off an on. I made the smallest jump in size/pitch I could find. Perhaps you will have better luck with the 8hp.

Curt

 

[dbsea]

Thanks for the insight Curt. I ordered two steps down on the pitch (8" is standard, I ordered the 6"), and we'll see what happens. Good to have a spare prop in any case. If none of the above works i'll probably just suffer until its time for a better/bigger dinghy and motor setup with different davits.