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Old 20 June 2011, 10:14   #1
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Speed/Gear Questions

Hi All,
My first post here, and am already looking for a bit of advice! Bought a new Rib last year, and have noticed a few little issues with it that I would like some advice on. Have listed them below:

- It seems to do only 32 knots max whether fully loaded with dive kit or empty. Shouldn’t a 200 power it a little faster than that? It's a 6.4m rib...

- Reverse seems extremely ineffective and doesn’t seem very good at all. Is that normal?! I don't remember noticing it on other ribs we've had.

- When I start the engine I always need to use choke and idle throttle, even when warm. It also sometimes seems to give up starting after a few seconds. Always starts after a couple of goes though. Any ideas?

Thanks for any help!!
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Old 20 June 2011, 10:36   #2
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Hi Calne,
First question has to be what rev's are you getting at WOT (wide open throttle) and what pitch prop are you using? 32 knots does definately seem slow.
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Old 20 June 2011, 10:44   #3
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Then check compression on each cyl

Have you tried playing with the tilt ? Does it make any difference at all ? Will give couple extra knots.

Starting issues seem normal dependant on it's age but again may not be firing on all 6.... I had one a while back (blackmax V6) sounded great, ticked over well but under load (ie on the water) would give similar results as yours. Turned out to be ring failure on 2 cyl (giving 65psi instead of usual 135ish).

That's worst case though.... Sounds prop related if reverse affected too

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Old 21 June 2011, 09:19   #4
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Right, sorry for the delay but I had to check the prop pitch! It's a Quicksilver Laser 2 with 21 deg pitch.

I can't tell you what the WOT RPM is at the moment, I took it out at the weekend to find out but spent the whole day climbing waves. I will try again soon though.

I have played with the tilt, and the 32mph is the max I've managed to get to...

Hope it's not compression, but will get it looked at if nothing simple I can do myself...

On another note, anyone know of a good re-tubing company in the south west? And what I should expect to pay for a 21' rib?

Thanks guys for all the help so far.
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Old 21 June 2011, 11:12   #5
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A rough gues without all the info but 21" is probably about right.

Sounds daft but worth checking all your throttle linkage etc to make sure you are getting full throttle when the levers right down
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Old 21 June 2011, 11:14   #6
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Quote:
Originally Posted by martini
A rough gues without all the info but 21" is probably about right.

Sounds daft but worth checking all your throttle linkage etc to make sure you are getting full throttle when the levers right down
Good points, again the blackmax models suffered from the linkages breaking but we don't know what engine the chap has yet....

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Old 21 June 2011, 14:13   #7
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Sorry, more details required!!

It's a Black Max V6 200HP with the serial number 0C127208...

Not sure what year that makes it. Tried looking it up and got two results, 1986 and 1989, but it's probably me looking in the wrong places!

Thanks again guys...
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Old 21 June 2011, 14:43   #8
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Quote:
Originally Posted by Calne Diver
Sorry, more details required!!

It's a Black Max V6 200HP with the serial number 0C127208...

Not sure what year that makes it. Tried looking it up and got two results, 1986 and 1989, but it's probably me looking in the wrong places!

Thanks again guys...
It's 1989 ~ check the linkages first then get the WOT revs then get a compression check done both from cold and after it's been run 15 mins to warm it up.

Keeps informed of your progress

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