Fairline Sprint 21 Leg Query

[Drew64]

Just a quick query,
we are having difficulties in finding the "optimum" setting for the leg angle, have tried everything from -4 to 7 spent this morning tyring different settings at speeds from 7 knt's to 15 knt's but could not seem to attain the correct setting for the speed we were travelling.
Ended up burning more fuel than normal...

Any pointers much appreciated.

Andrew.

 

[Kawasaki]

Just a quick query,
we are having difficulties in finding the "optimum" setting for the leg angle, have tried everything from -4 to 7 spent this morning tyring different settings at speeds from 7 knt's to 15 knt's but could not seem to attain the correct setting for the speed we were travelling.
Ended up burning more fuel than normal...

Any pointers much appreciated.

Andrew.

Presume you have hydraulic trim?
Start with the leg in the 'down' position
'Hit it' get on the plane and trim 'out'
You should 'plane' at about 16 kts then trim for optimum balance/performance
Planing hulls are only efficient 'planing' or going slow
Up to , lets say with your Fairline, 6 /7kts
Then when on the 'plane' at 16 and above the hull will like it
Don't try and find out what is comfy or economical if the water is choppy , you won't be able to 'feel' what is going on
Don't 'dab' at the trim button, get on the plane and press the button for two seconds continuose to start and feel what is happening
Then trim right down again and feel what is happening
Do this, then try again and push for 3 secs and 'feel' what is happening
The bow should rise a bit and the steering become lighter
Try this technique a few times with differing amounts of time on the trim button
Return to 'down' whilst on the plane and you will get the 'feel' then trim up/out again
Fliipen eck this sounds like a load of grief whilst typing but it's a hell of a job to explain and two minutes if 'hands on'!

 

[Solitaire]

Just a quick query,
we are having difficulties in finding the "optimum" setting for the leg angle, have tried everything from -4 to 7 spent this morning tyring different settings at speeds from 7 knt's to 15 knt's but could not seem to attain the correct setting for the speed we were travelling.
Ended up burning more fuel than normal...

Any pointers much appreciated.

Andrew.

I had a Sprint for 8 years . Went from petrol to LPG to a diesel . At the speeds you are quoting the boat is not fully on the plane. Therefore playing with the trim will do very little . You need to open the throttle fully to get properly on the plane. Then trim the leg , you need water flow to effect trim .
Kawasaki has given you hints, try them. But trim will not work at slow speed, what it will do is effect your ability to steer.

 

[Chris_d]

As others have said the boat will be displacement mode up to 6/7 knts and planing at 15knts+, it will not work in between except burning horrific amounts of fuel and pointing towards the sky. Same rule applies to almost any planing boat so don't even try to make it work between 7 and 15knts.