Lightest 4hp or 5hp

[Searider]

Evening all.

I have just purchased the smallest RIB in the world - a Bombard AX2000 and have a 3.5hp Tohatsu 2 stroke for it. I had hoped it would plane with this engine and whilst I wasn't surprised it didn't with my 90ish kg was disappointed that it wouldn't with my much lighter teenage son driving.

I think I need a little more power whilst keeping the weight down.

So, what are the lightest:

4hp?

5hp?

(I'm not a fan of the OMC 2cyl 4hp engines)

[jeffstevens763@g]

Originally Posted by Searider

Evening all.

I have just purchased the smallest RIB in the world - a Bombard AX2000 and have a 3.5hp Tohatsu 2 stroke for it. I had hoped it would plane with this engine and whilst I wasn't surprised it didn't with my 90ish kg was disappointed that it wouldn't with my much lighter teenage son driving.

I think I need a little more power whilst keeping the weight down.

So, what are the lightest:

4hp?

5hp?

(I'm not a fan of the OMC 2cyl 4hp engines)

I would guess Suzuki have a look on Ron hale marine and compare

[Fenlander]

What's it rated to?

[Searider]

4hp

Previous owner used a 5hp without issues.

[Searider]

Originally Posted by jeffstevens763@g

I would guess Suzuki have a look on Ron hale marine and compare

I'm looking at used - so guessing 2 stroke.

[Fenlander]

I think your 3.5 will weigh about 13kg... going up to a 4 or 5hp will probably take you to 20kg. Is that too much for what you had in mind?

If it's OK then I quite like those Mercury/Mariner/Tohatsu 2-stroke 5hp that look the same as the 4hp models.

Like one of these...

https://www.youtube.com/watch?v=ce5ykBGkn48

[Searider]

That should do it.

Yes - the tohatsu is about 14kg.
I had a 4hp yam 2 stroke a couple of years ago and although heavier was manageable.
Are the 5hps about the same weight?

[Max...]

Aren't 4/5/6 all the same block/weight generally? If so go 6.

[Rover310]

Originally Posted by Max...

Aren't 4/5/6 all the same block/weight generally? If so go 6.

Depends on the make. My 90's Evinrude 6 hp shared the same displacement powerhead and parts group with the 8 hp, the only difference being a larger carb bore on the 8. They weigh the same. Only way to tell them apart from one another was the '6' or '8' decal on the back of the hood.

Whereas the 5 hp and smaller Evinrudes of similar vintage also shared a common powerhead/parts group with each other, those motors typically having built-in fuel tanks as part of the motor cover. The 6 & 8 use remote fuel tanks.

[badbaws]

have you got a floorboard as that makes a huge difference.

Get a second 3.5hp run in tandem.. I did this with two x yamaha maltas. i used to get 6 knots with one and got 13 knots with two of them, plus it was great fun!

Failing that get a yamaha or tohatsu 5hp as they are same weight as 4hp but single cylinder. Johnson use twin cylinder but are much heavier. normally 4/5hp same block and 6/8 same block Yam / Merc /Mar / tohatsu

I have had my Avon Redseal planning with a 5hp and that is with the round transome and bracket. It did have floorboards.


RIBnet Forums - badbaws's Album: wake - Picture