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Old 31 August 2019, 10:39   #21
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I used the same pitch as it was what I was needing to get the max RPM as well as stern lift. Best to call someone like steel developments and they will advise you.
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Old 06 September 2019, 12:48   #22
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Originally Posted by simonl View Post
Same pitch?


If your current prop was the right size you prob need to go down a pitch for a 4 blade to achieve the same wot
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Old 06 September 2019, 15:51   #23
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Having thought about it a bit further I would avoid the automatic trim tabs because with my 4.2m rib we often drive up to the beach and drop off passengers and/or anchor close to the shore. Although we keep a close eye on the rib There have been many times with an outgoing tide that it is touching bottom when we shove it out further and Re anchor.
I would personally avoid anything sticking out below the hull as I think it is just asking to be broken on a rib.
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Old 06 September 2019, 18:54   #24
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Having thought about it a bit further I would avoid the automatic trim tabs because with my 4.2m rib we often drive up to the beach and drop off passengers and/or anchor close to the shore. Although we keep a close eye on the rib There have been many times with an outgoing tide that it is touching bottom when we shove it out further and Re anchor.
I would personally avoid anything sticking out below the hull as I think it is just asking to be broken on a rib.
I wouldnt even consider tabs on something that small. Something seriously wrong if you cant get that to perform properly by playing with weight distribution
Overkill fitting trim tabs to that size of boat imho
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Old 07 September 2019, 08:11   #25
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60HP four stroke on a 4.2m RIB is going to be heavy, Some weight up front will be the best way to fix.
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Old 10 September 2019, 07:03   #26
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Originally Posted by OSPREY RIBS View Post
60HP four stroke on a 4.2m RIB is going to be heavy, Some weight up front will be the best way to fix.


I agree with this.

I have a Futura with a 50 4 stroke and when I first tried got it on the water, it had the same problem as you describe. I moved the seating, console, fuel and batteries further forward (only the engine at the stern) and it’s fine now.
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Old 10 September 2019, 22:33   #27
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Quote:
Originally Posted by OSPREY RIBS View Post
60HP four stroke on a 4.2m RIB is going to be heavy, Some weight up front will be the best way to fix.
100%
I had an early Merc 4stk (90hp) on a used 5.5 RIB (fitted when I bought it) it was Brute Heavey ...Slow and killed the performance...swapped out for a new etec 130 and transformed it
Both in handling and Top end...32knots - 45+
....Maybe that's what you remember Chris!?
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