Have I just gone too big!??

[jwalker]

I had a Destroyer 6.5 for a number of years, it had 200hp on the back. It travelled well, BUT, I sold it to a group of divers and we went for a decent run as an intro to the boat - me, my wife and four divers at the stern and nothing forward of midships - it was ok, just, but it did not handle well and almost hooked at one point. It's character changed completely when excessively stern heavy.

Keep it well balanced is my advice, the bow is pretty high lift so can carry a lot of weight. It went through some big seas buy I never stuffed it, a wall of water around the tubes many times but it never went under.

[CJL]

Originally Posted by carldalmas

They can be dangerous
when overpowered ! As air gets under tubes and flips them over !
Main thing remember you have no boat insurance
if the hull is rated for a lower hp engine
Check your cover
Great fun if you know what your doing keep bow down !

I always LOVE how some people come out with the insurance comment and that the boat isn't rated for this or that.

Perhaps my insurance policy is different to yours? Just a thought!

Perhaps my boat had been properly engineered to take it by somebody who knows what they are doing? Just another thought?



CJL

[CJL]

This is a 5.5m Delta with a 225hp Suzuki on the back operated by the local F&RS......

[jeffstevens763@g]

Originally Posted by CJL

This is a 5.5m Delta with a 225hp Suzuki on the back operated by the local F&RS......

Always loved the delta

[keef1234]

My delta 5.5 has a 130 yam v4 and it's lively, safe but quick

[Safi]

Originally Posted by nugent

Also had a 150 merc on a 5.5 Humber Attachment 128080

Went well with no issues and I know it's still going now after 8 yrs

Did you have problem with cinewalkin or bounsing, how fast did it go?

[carldalmas]

Originally Posted by Safi

Did you have problem with cinewalkin or bounsing, how fast did it go?

Over powered boats that may be ok depends on experience driving them has a big floor !
If you have exceeded the boats engine rating
1. The transom may not take the torque it was designed for
2 your boat insurance will be invalid ! in any claim !

[Poly]

Originally Posted by carldalmas

If you have exceeded the boats engine rating
1. The transom may not take the torque it was not designed for
2 your boat insurance will may be invalid ! in any claim !

Fixed that for you...
Plenty of discussion of those topics here over the years including people who have been open with their insurer and had no problems.

[boristhebold]

Contact the rib manufacturer and see what they say in terms of max weight and HP. And get them to put something in writing.

And then contact your insurer.

If the manufacturer states its OK and the rib has been tested or whatever need be with that setup and all past fine, and if your insurance company is happy with that then thats one element sorted.

If either raise issues then think very carefully about doing it you dont want to have an accident and hurt anyone or be paying out for the rest of your life and have to sell house etc if something nasty happens.

If it were me, no I would not put that on the back.

[Daibheid]

Originally Posted by Jeff

I had a 5.5m Cobra (1999) with a 150 Opti and never felt it was overpowered.... or unsafe.

I ran the same boat for years with a Yamaha F100. It would get up to over 43 knots one or two up but felt it was going to bite and hard! Chine walking or pulling really hard to starboard. A great package with a lot of weight on board or driven a bit slower but a bit tail heavy. Probably had a 60 two stroke on from the factory

[Safi]

Originally Posted by CJL

This is a 5.5m Delta with a 225hp Suzuki on the back operated by the local F&RS......

I seriusly doubt this could be driven att full throttle 🧐

[nugent]

Sorry replies on wrong page

[nugent]

Originally Posted by Safi

Did you have problem with cinewalkin or bounsing, how fast did it go?

Can Not remember speed of mine now but handled faultlessly

I put large fuel tank in the floor changed out for a better heavier built console also fitted further forward all changing weights etc,

It's a great boat and still going well to this day I also put a new transom in on the build

[Safi]

Originally Posted by nugent

Can Not remember speed of mine now but handled faultlessly

I put large fuel tank in the floor changed out for a better heavier built console also fitted further forward all changing weights etc,

It's a great boat and still going well to this day I also put a new transom in on the build



Attachment 130611Attachment 130612

Ok, the bottom has to be different on the humber?
People is geting about 43-44 kts with 150hp on sr6
So your humber (half that weight) sould easily do 50+ kts
I also have a big tank in the front, the tank is about 85kg empty.
I filled it to the top about 200liters + myself about 110kg and 2xbatteries 40kg under the console so alot of weight but its still chinewalks badly.
All that weight resulted in bounsing att 30-38 kts