Buying first rib questions...

[Smagu]

Hello folks.

Got lots of helpful advice on my last post (back for more haha)

So I'm debating buying my first rib. I've been lucky enough to drive plenty of brand new boats/ ribs however this is the first I've had to pay for myself and budget dictates.

Its an extremely well maintained 5.5m humber unsure of model but its not deep V with 3 x single jockey seats. Early 2000s. And some nice electronics.

The questions I have are.

1. Its got a 60hp two stroke motor. I am aware this is slightly underpowered, my main use for it will be on a loch and very nice summer days close to shore at sea. I would like to tow a knee board possibly too. Maybe a ringo. What speed could I realistically expect with myself and 2 passengers. Previous owner claims they could get around 30knts with 1 passenger and up onto a plane easily with 5.

2. Its on an unbraked trailer (original trailer). With a 60hp engine and in full kit with a 4hp aux engine. Will I be over the 750kg max unbraked weight?

3. The two stroke engines start no problem and sound superb. However there is a small chip in the prop I have included a photo. Is this a major issue or will it be acceptable for the moment? This is by far the worst damage on the prop there are one or two very very small marks but nothing like this.

Thanks so much in advance

[HDAV]

1: take it out and try it might suprise you should be enough for a ringo may take a while to get on the plane a knee board might be an issue light rider should be ok

2: take it too a weigh bridge as stripped down as possible (no gear or fuel) pop aux in boot etc and hope

3: hard to tell but looks fine can smooth it out with a file If rough

[oisin.higgins]

1. 30kts might be possible. I get 24kts on a 5.6m or 5.8m deep v Osprey Eagle with a four stroke 60hp Yamaha, its over propped though, so 30kts is definitely possible.

As for planing, I could plane with 6 hefty adults or 4 divers and a coxswain so it should be fine.

2. As HDAV suggests bring it to a weigh bridge. It's impossible to say otherwise:
- I found a 5.8m Lencraft with a 70hp four stroke Honda to be about 1050kg
- I found a Ribcraft 5.45 with 90hp Mercury Optimax sits on a braked trailer rated for 1.3t, though I've never had it weighed as I haven't needed to.

3. That prop will be fine, obviously not ideal, but I've seen and driven much worse. As long as there's no major vibration when in gear, all that nick will do is make it easier to ventilate (at high trim out/up angles) and cavitate (due to the additional hubble nucleation spots).

[HDAV]

Humber made several hulls in that sort of size iirc what’s on the makers plate? Also when it comes to older outboards trusting the cowl decal isn’t always the best bet check the engines spec plate should have a model number.

This may also help https://www.rib.net/forum/f8/humber-...-5m-59954.html

[Smagu]

Thank you Oisin and HDAV. I think for my intended use and first RIB its a good starting point!

[Smagu]

Hello Oisin sent you a pm there hope you don’t mind

[SimonCh]

Re the engine power, you may find that you need to be clever with people's positioning on the boat. If you're trying to pull up a boarder, the boat may struggle to get out the hole... so a couple of your hefty passengers seated near the bow will help.