25 Honda 4 stroke?

[Stu_000]

Just curious to see if anyone out there has a tinny around 4.2 with all gear etc on board with a 25 Honda 4 stroke on the back? Just want to know how it would perform with 4 adults on board. Also who uses one of those outboard planing thingos (can't remember what its called). I heared they can cause cavitation? Any info would be great. The boat I'm looking at is centre console.

Cheers

[Bear]

My experience is that it would struggle a fair bit with that much to push. You would probably want to look at around a 40hp.

Depends a lot on the hull as well though.

Quite a number of the guys have the fins and I have't heard of any cavitation problems.

Craig has a 30hp Honda on his with a fin. I'm sure if you drop him a PM he'd be happy to let you know what he's been through.

My 4.8 barra punt started life with a 25 Hp donk and at the start it was fine until I added all the gear you need in the boat to make it into a decent fishing rog - then it needed more that 25 ponies.

Even just the bare hull wouldn't plane with a 25 and 4 persons aboard tho - three it would plane - if tyou were going downhill with a tailwind - 2 was no trouble.

I's say you'll need 40 or 50 ponies to start with and save the grief having to change up to bigger HP later is my advice.

Cheers!

[jimi]

Stu, I have a 4.2m dingy with a 25hp 2-Stroke Johnson on the back and to be honest, I'd go with more HP. My boat has full floors, side decks, batteries, electric - all the breaming gear - so is quite heavy.

The 4 stroke is a heaver motor than the Johnson, which is a very lightweight model, so your problem will be worse. Plus you are looking at a center console layout which adds even more weight.

I fitted a stingray hydrofoil to mine, which helped enormously with getting onto the plane and low speed travel. Never had any cavitation problems either.

Still doesn't make up for a motor that is too small though. With 2 up, my boat is fine, but any more than than and it starts to struggle. Top speed with 2 people is 20 knots, 3 up is 16 knots, 4 up - it doesn't even plane.

Hope that helps

James.

[Stu_000]

Thanks for all the input guys. Probably won't be going out with 4 too often, but you never know. The hull is a savage 4.2 thats all I know. I'm going to check it out today. I think it has a Johnson/Evinrude 35 (2 stroke) on the back atm, but for an extra $600 I can go with the 4. Got my heart set on a 4 for all the reasons that have been talked about on various threads recently. If it was a 30-35hp 4 would be ideal but money is tight. Yeah reckon I'll go with a fin, I've heard they are ideal if your out alone for planing etc.

[Stu_000]

Considering the cost ($600 for a second hand 4 stroke) I reckon I can't knock it back. It has done approx 600 hours, which is a fair amount but then again it is a 4 stroke (current model) so I reckon its a good buy. It may be a bit overloaded but the boat is really only geared around to blokes fishing; should be enough for a while anyway.

[Craig]

Stu

As Bear mentioned, I have a 30hp Honda and initially it struggled to push my 3.85m Edgetracker when loaded up eg 3 blokes and a headwind.

I have raised the motor, added a hydrofoil and changed the pitch of the prop (i.e. new prop) and it performs quite well now.

The hydrofoil assists in getting onto the plane earlier and maintaining that at slower speeds but it did not overcome the need to adjust the prop pitch and will not help an underpowered boat. Hydrofoils may produce some cavitation it just depends on the combination of type of hydrofoil, engine, engine trim, engine height and hull but in general opinion is the gains outweigh the losses.

I feel that with the 25hp your boat will be underpowered and you will be frustrated with its’ performance (or lack thereof). However as you seem to think it is too good a bargain to pass up, look on it as a learning experience, experiment and when finances allow you will have worked out exactly what motor you want.

Have fun and enjoy.