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Old 06 April 2008, 08:15   #31
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Country: Ireland
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Make: HUMBER DESTROYER 5.8
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Quote:
Originally Posted by Jono Garton View Post
Hi

Trim it half up with the engine not running and stand on the skeg, if it drops/lowers their is somthing wrong with the pump.

Have you checked the fluid level in the pump?

As the boat been left on the water for a long time?

Is there any corrosion around the pump?

Jono
Will do this so to see if it drops.
Ye opened the fluid level and seems to be ok, hard to see level but it seems to be full.
No boat was only ever in and out same day. Hasn't been used since last year.
no sign of corrosion.
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Old 06 April 2008, 08:30   #32
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Originally Posted by ciaranp View Post
Will do this so to see if it drops.
Before doing this make sure that there is plenty of weight up front on the trailer. Weight of an adult on the engine might be enough to tip the trailer balance ... and you don't want the skeg (or boat it that is first) hitting the deck. don't ask me how i know
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Old 06 April 2008, 09:32   #33
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Originally Posted by Polwart View Post
Before doing this make sure that there is plenty of weight up front on the trailer. Weight of an adult on the engine might be enough to tip the trailer balance ... and you don't want the skeg (or boat it that is first) hitting the deck. don't ask me how i know
ok will do..
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Old 07 April 2008, 07:01   #34
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If I tilt well up to navigate shallow water and increase the revs much above tick over, the engine trims down. In calm water to get maximum speed for the revs. I trim right up. The engine reaches its maximum trim angle and moves down a couple of degrees.

I was told (a long, long time ago in the age before RIB's), to get maximum speed in flat water, to trim up until the boat starts to porpoise, then in a little. I can't get my Humber to do that as the engine won't trim far enough.

Jono's right, certainly my Destroyer is very sensitive to trim and just a dab on the switch can make a huge difference to comfort and controlability. You need to play it all the time. Contrary to a lot of the advice I see here, I keep heavy 'cargo' aft of the jockey seat and out of the bow.

I think it's the angle of the Destroyer transom which fools the engine into thinking it's tilted up too much, when in fact it's pretty much level.
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Old 07 April 2008, 11:42   #35
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Originally Posted by alystra View Post
If I tilt well up to navigate shallow water and increase the revs much above tick over, the engine trims down. In calm water to get maximum speed for the revs. I trim right up. The engine reaches its maximum trim angle and moves down a couple of degrees.

I was told (a long, long time ago in the age before RIB's), to get maximum speed in flat water, to trim up until the boat starts to porpoise, then in a little. I can't get my Humber to do that as the engine won't trim far enough.

Jono's right, certainly my Destroyer is very sensitive to trim and just a dab on the switch can make a huge difference to comfort and controlability. You need to play it all the time. Contrary to a lot of the advice I see here, I keep heavy 'cargo' aft of the jockey seat and out of the bow.

I think it's the angle of the Destroyer transom which fools the engine into thinking it's tilted up too much, when in fact it's pretty much level.
Thanks for that, hope to get out tomorrow to mess with it for a bit.
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Old 07 April 2008, 11:48   #36
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Quote:
Originally Posted by alystra View Post
Jono's right, certainly my Destroyer is very sensitive to trim and just a dab on the switch can make a huge difference to comfort and controlability. You need to play it all the time. Contrary to a lot of the advice I see here, I keep heavy 'cargo' aft of the jockey seat and out of the bow.
That's interesting - I keep mine trimmed well out all the time because it seems to make relatively little difference to mine apart from cavitation on tight high-powered turns, and trimming in for rough conditions to avoid it slamming too much. The console in mine is well forwards (originally set up for divers) and there is about 80L of fuel in cans in front of the console.
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Old 07 April 2008, 12:02   #37
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The Destroyer my club had was very well behaved and wasn't sensitive to trim at all. I would suspect that all the weight ar the stern would not help. Personally I intend to stick two batteries and two fuel tanks at the bow of mine to even out the weight of the outboards on the transom. Using the motor trim to keep the stern up is less efficient than having good weight distribution front to rear.
I have never had any boat too light at the bow but it is all a compromise, too light and you bounce about on even little waves, too heavy and you stuff the bow in any kind of sea.
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Old 07 April 2008, 12:45   #38
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That's interesting - I keep mine trimmed well out all the time because it seems to make relatively little difference to mine apart from cavitation on tight high-powered turns, and trimming in for rough conditions to avoid it slamming too much. The console in mine is well forwards (originally set up for divers) and there is about 80L of fuel in cans in front of the console.
I reckon that's because of all the weight in the forward part of the boat, Stephen.

Last year I took an extra 70kg. of kit aboard. Stowed it forrard. Full up/out trim, 3600rpm. which usually gives me 23knts., very comfortable in the chop but speed down to 20knts.

I moved the 70kgs. aft of the jockey seat, between it and the bench seat. Same revs and conditions. Speed then 22.5knts. and the ride bumpy enough to trim in/down a tad, which brought the speed down to 22 knts. A gain of two knots at same revs. so more miles per litre.

I know I'm obsessed with miles per litre - a Yorkshireman living in Scotland. But, after years of sailing everywhere using 'free' energy, every time I push the throttle forward and watch the beautiful scenery fly by, I see it through an image of a jug full of petrol being poured down a plughole. The image fades if I know I'm getting maximum efficiency.
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Old 08 April 2008, 06:42   #39
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Could be - I took the two cans of fuel out once to see if I could crack 40kt and gained about a knot trimmed right out - previous max of 39.3kt went to 40.2kt on the GPS. Unfortunately there is quite a lot of weight on the driving seat too so that probably doesn't help - still I suppose it keeps the bow down in rough conditions

Getting back on topic a bit, it is a shame they changed the transom on the Destroyers - mine is horizontal either side of the engine making it easy to mount an aux, but the new ones would need a bracket due to the shape. I wonder why they did it? Any advantage to the new design?
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Old 09 April 2008, 11:16   #40
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Quote:
Originally Posted by BogMonster View Post
..............
Getting back on topic a bit, it is a shame they changed the transom on the Destroyers - mine is horizontal either side of the engine making it easy to mount an aux, but the new ones would need a bracket due to the shape. I wonder why they did it? Any advantage to the new design?
Yes, I noticed that and don't think it improves the looks and you're right about fitting an auxiliary. I wonder if it's anything to do with having to increase the freeboard aft so that the design may comply with the commercial codes? I have heard that freeboard at the transom is a major issue for the MCA. I know if I go astern in anything above a ripple, we start to take on water.
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