destroyer leaning under full power at speed

[montu]

hello,i have just bought a 5.3 humber destroyer and a 115 optimax ,(have not had a chance to speak to the marine shop who fitted it to see if they have any suggetions)but sometimes we can be going along nice and then when we open the throttle sometimes the boat will lean to the left quite a bit and once or twice has done it to the right,also the steering becomes very hard to turn to the left when you put a few thousand revs on but is always fine to the right.I know you can adjust the plate above prop which i need to try.Has anyone had the same experience or any suggestions?thanks!

[J S]

Have you tried trimming up/out when you start to apply more power. The stiffer steering is very common if you don't use the trim at speed.

V.Nice Rib BTW

Hope that helps

James

[Searider]

Looks like quite a lot of power on a 5.3 - should be lively!

As said before try altering the trim for different speed settings. With my 5.4 searider with 90hp and old fashioned cable steering the trim had to be adjusted in order to balance the steering up.

Play with the trim until the steering goes light.

[jwalker]

Originally Posted by montu

I know you can adjust the plate above prop which i need to try.

Do this first. Aim for a situation where when you are cruising the boat drives a straight line. Your engine manual should tell you how to adjust the tab.

The rotation of the propeller tends to lean the boat to the left under power. Don't confuse this with the boat listing towards a side wind. If the wind is blowing from the right, the boat will lean to the right and vice versa. It's actually your steering against the wind which causes the list but it doesn't feel like that.

also the steering becomes very hard to turn to the left when you put a few thousand revs on but is always fine to the right.

When properly set, the tab will help eliminate that but if you apply lots of revs at slow speed with the steering set to the left, the forces are so great you may not be able to wind the steering back without reducing the revs. Take care with that; it's a normal feature and you'll need to learn to handle it.

[montu]

thanks for those comments,i will give them a try.Have just spoke to sue at humber and she said the company who fitted the engine may not have offset it.

[Jono Garton]

Hi

We are currently fitting engines 40mm to Starboard on Destroyers, they do love trim as James Said.

Jono

[BogMonster]

Mine is very heavy in the steering if the trim is wrong too

[montu]

hello Stephen L,does your boat ever lean to one side under power,i dont mean if you are heading towards say an object then when you add power you go offline,i mean one tube in the water and the other one towards the sky so the deck is on an angle as if there were half a dozen people sitting on one side of the boat?

[Hightower]

Doesn't every boats steering get heavy during trimming at different speeds? Just learn to use the right trim/speed for your RIB, Hydraulic steering helps during the heavy steering phase.

[Alex Brown]

Hello,

I was just talking with Jono about this in the lock at Milford on Sunday afternoon!!

Trim the engine up pretty much as high as you can and you should find the "lean" will go - my Destroyer does this if the engine is any further down than the 3/4 trim position.

-Alex

[Colin F]

Originally Posted by Alex Brown

Hello,

I was just talking with Jono about this in the lock at Milford on Sunday afternoon!!

Trim the engine up pretty much as high as you can and you should find the "lean" will go - my Destroyer does this if the engine is any further down than the 3/4 trim position.

-Alex

same here - spot on
Great boat by the way

[montu]

Hello Alex,nice to here am not the only one to have this happening.Did not think the trim would stop the leaning when it was happening and look forward to trying it out.Also the engine does not look to have been fitted offset which prob isnt helping,thanks!

[montu]

cheers Colin,how long did you spend running the engine in?was told ten hours,almost there and have started to open it up,what a rocket!was doing 43mph with 3 in at about 5100-5200rpm and still had a couple of mph in it.What prop did your engine come with?

[Colin F]

not sure on prop, if jono garton or ian sharlott see this, they'll give you the answer. mine has made 41.5 knots at full whack, although it did start to chine walk then. plenty fast enough for me!! didn't dare look at the rev counter then

[montu]

mine has a black prop,just wondering if yours is the same or ss

[Ian Sharlot]

Originally Posted by Colin F

not sure on prop, if jono garton or ian sharlott see this, they'll give you the answer. mine has made 41.5 knots at full whack, although it did start to chine walk then. plenty fast enough for me!! didn't dare look at the rev counter then

It is a Black max, Can't remember if it was 19p or 21p but would guess at 21p.

[Colin F]

Originally Posted by montu

mine has a black prop,just wondering if yours is the same or ss

decided to go for an ally one, i can't remember the pitch of it either

[psychopic]

sounds like chine walk to me. using the trim will should sort it at speed. Nice boat by the way. I have the 5.3 Ocean pro with a 90, would love to have the 115 on it, would go like a rocket. Do you know what kind of lph you getting at full speed?

[montu]

hopefully out tonight so will let you know

[alystra]

My 90hp was fitted by Humber. Offset about 2 inches. Made it go straight with the trim tab thingy on the engine. I have never had any leaning problems with the boat. Strong beam winds make it heel, as all boats do.

Steering can lock up at anything more than a fast tickover if the engine is trimmed in/down too much. (Easy to do as the transom is raked and my trim guage no longer works - I have to turn round and look ) Trim up/out and the problem disappears.

Not sure about the wisdom of using hydraulics to overcome the results of bad trim, I'd have thought it wouls put enormous strain on the engine tiller (or whatever)