Twin engine possible?

[jameswallace]

Greetings all. Ive come back to owning a rib again!!

I sheared the trim tilt on the yammy 100 on the back of my 2002 ribeye 5.8. So im. I am contemplating twin 70 hp's on the back. Is this possible? Will i have ebough room?

Ill upload pics later.

I would like i did wih my old avon i had use a stainless sheet across the transim to re enforce

[lakelandterrier]

Welcome back to the world of RIBs.

Why would you want twin 70's on a 5.8m? You won't get the equivalent power of a single 140 which is what I'd want on a 5.8m boat.

Unless you're going change the fuel tank to 2 separate tanks and systems I can't see the point from a contingency / back up point of view. Why not fit a 120 / 140 with a small aux if it's backup that concerns you?

More inital cost than a single power unit, twice the servicing cost.

What is the transom rated for on weight / power? That's the first thing to understand.

[jameswallace]

Thanks.

I need to get info on the transom yes.

Im a certified outboard mech amongst other things so service cost isnt something i bother to consider to be honest

I was thinking twin 70 2 strokes. Its findinf a 130-140 hp that seems tricky. Its not for back up purposes i like twin engine for some reason!!

[Bern Hanreck]

pm sent.....Bern

[Pikey Dave]

I've recently sold a twin engined RIB & I loved it. However, the boat was designed & built from the ground up as a twin rig. Twin fuel tanks, batteries, fuel & electrical systems, re-inforced transom etc. Personally I wouldn't convert a single setup to a twin unless you're prepared to go the whole hog, otherwise you'll end up with something neither here nor there. Twin 70's will give you performance of a single 115 or thereabouts, which could be a tad disappointing.

[jameswallace]

Having thought about it you're right. I hit a cross roads now. I love the hull but the tubes are in ok condition but not a great sized diameter. Im not confident going down waves with it. Ive been in serious weather in ribs before but i just don't have the confidence that the tubes will do there thing on a nose dive. So im tempted to re tube and re engine the boat. As well as rebuild the trailer. This would cost me what a twin engine rib would cost. There is nothing wrong with the tubes apart from the lack of size and they're a bit tatty round the edges

[Starovich]

Originally Posted by jameswallace

Im not confident going down waves with it. Ive been in serious weather in ribs before but i just don't have the confidence that the tubes will do there thing on a nose dive.

Sounds like your saying the tubes prevent a stuff? In my experience you can stuff anything, if you try hard enough or are not concentrating. If you are relying on tube volume to stop the burying, i think you'll find the tubes pull off the boat, hence some military types having straps to assist.

Its more about throttle control, trim and wave/swell awareness, most ribs will be ok and if you think its too much for the boat, it probably is

[jameswallace]

Ive de tubed a rib before (not my fault) so been there done that. That wasnt fun. I know they dont stop you stuffing it but it does help! I dunno just doesnt feel comfortable down the waves. Ive had smaller boats in bigger swells and not had an issue. Its possibly a tad under powered with a 100hp on the back

[willk]

Originally Posted by jameswallace

I dunno just doesnt feel comfortable down the waves. Ive had smaller boats in bigger swells and not had an issue. Its possibly a tad under powered with a 100hp on the back

It's a small Ribeye. Surely the issue here is the low bow, not the small tubes? I'm not knocking Ribeyes but I wouldn't pick a small one to go surfing swells in. IIWY, rather than re-tube, or re-engine, I'd re-boat.