Trimming my tinny

[tinman42]

I am having a lot of trouble trimming my 4.2mtr Stacer. I am running a 40 HP Yammy, elect start, power trim and at take-off the bum digs in and bow points to the sky. The angle is frightening as it gives the impression that 1 strong gust of wind and over it goes. After a few moments of building up speed it 'pops' up, planing and running nicely. I have the motor trimmed all the way in on the trim and tilt and am on the last hole down on the motor support bracket. I have just fitted a 'stingray' aquafoil on the motor which helps a little. I have moved everything possible (fuel tank, gear, tackle box etc) as far forward as possible.

This condition is only evident when running slowly . Basically, if it is not planning it is pushing a lot of water and riding at a 45 degree angle.

Is it possible to 'pack' the motor attachment plates to the transom to alter the angle? Would some bags of sand in the bow help?

I have run out of ideas, can anyone help?:'(

[station-rat]

Transom wedges will give you some more trim angle.Avaible at any marine dealer

[Chimo]

Forgive the Q but what do you weigh?

Cheers
Chimo

[foxx510]

I've seen lots of tinnies do this when they are about to come on to plane, I think it's a common problem.

[CreelReaper]

Hey Tinman42,
Yeah I would be looking at the wedges also. Maybe also check the height of the motor. There are a couple of threads into setting up motor height correctly in previous threads. Or conversely check the yammie website for downloadable manuals for your model. Hope this helps.

Shane

[thelump]

Forgive the Q but what do you weigh?

Cheers
Chimo

Hi Chimo

He would have to a fairly massive unit for weight to enter into the equation. I had a 445 tinny with a 40 yammy on the back and used to sit 2 at the rear to take off and it never lifted that much. And I am 120kegs.:-[ Most likely engine position. Either that or he may be the Bigshow from wrestling;D

[disorderly]

Maybe also check the height of the motor. There are a couple of threads into setting up motor height correctly in previous threads.

Shane


Try this first.http://www.ausfish.com.au/vforum/../yabbfiles/Templates/Forum/default/wink.gif
Could be as simple as the motor sitting too low in the water.

Scott

[STUIE63]

My guess is engine is too low
Stuie

[wiz]

Take the adjustment pin out all together and you can trim motor in further for takeoff.

[upstart]

What fin did you fit? I had a 40hp Yammie on a 13ft Haines Sea Wasp and I fitted a permatrim. Made a huge difference.

[dreemon]

Mine was doing the same as yours, 4.1 40hp tiller and I raised it 70 mm fr. top of transom and added a permatrim, (70mm will be alot more than you'll need), I have the trim pin at 2nd fr last out, hole shot onto the plane is great and got 4 klm more top speed, ..... ...

[Lancair]

Have a look at this short video I made when I added a permatrim to my boat. Etec 40 on 4.2m stessco catcher. Solo, I had some scary moments, esp if I had to slow to cross large wake etc. With one up the front, it wasnt bad at all.
Now I can take off with two people sitting on the rear seat without dramas, but still would have crew up front crossing a bar or big wake etc for balance.

[/URL]
[url=http://s135.photobucket.com/albums/q153/Biggles70/?action=view&current=permatrim1a.flv]Video (http://s135.photobucket.com/albums/q153/Biggles70/?action=view&current=permatrim1a.flv)

Andrew

[bushbeachboy]

A Permatrim will help you a lot. I have one fitted to my 40 Yammie 2 stroke with PTT on my little 4.1 Polycraft. The little poly is a bit bum heavy, and moreso with the nearly 100kg weight of the 40. Then you put my fat posterior onto the seat, and add the weight of the battery and fuel tank down the back and you potentially have a problem. The Permatrim works a treat, and when the going gets a bit rough for the front passenger, I sit him down the back with no worries. Full trim in for take-off and it pops out of the hole effortlessly, then a few seconds later trim out for best running. The Permatrim has made all the difference.

[disorderly]

A Permatrim will help you a lot. I have one fitted to my 40 Yammie 2 stroke with PTT on my little 4.1 Polycraft. The little poly is a bit bum heavy, and moreso with the nearly 100kg weight of the 40. Then you put my fat posterior onto the seat, and add the weight of the battery and fuel tank down the back and you potentially have a problem. The Permatrim works a treat, and when the going gets a bit rough for the front passenger, I sit him down the back with no worries. Full trim in for take-off and it pops out of the hole effortlessly, then a few seconds later trim out for best running. The Permatrim has made all the difference.

I thought the permatrim would help more when the the boat was actually up on the plane whereas this problem seems to lie with the initial holeshot....as in getting the boat up to planing speed..

happy to be corrected though...http://www.ausfish.com.au/vforum/../yabbfiles/Templates/Forum/default/smiley.gif

My old tinny did the same (nose in the air when starting off) and I raised the motor 60-70 mm and it's great now.(originally thought it was trim but it was just height.)

Scott

[tinman42]

Forgive the Q but what do you weigh?

Cheers
Chimo


Less than 100kgs

[tinman42]

It would appear that I need to raise the motor height. Is this a precise science or just guess work as to how much to raise it or is this a job for a professional outboard mechanic?

[FNQCairns]

IMO go with the wedges, they will fix your problem, if you fit a foil it will fix it too but at a performance cost near everywhere, the wedges will just fix it, no negatives.

cheers fnq

[foxx510]

It would appear that I need to raise the motor height. Is this a precise science or just guess work as to how much to raise it or is this a job for a professional outboard mechanic?

If you dig out the handbook for your engine, it should show the correct setup height on the transom. On our Honda, the correct height is to have the horizontal line of the anticav plate on the leg 0-50mm below the keel line.

[tinman42]

Thanks to all who posted replies, your help was invaluable. Based upon what was said I fitted a SE SPORT 200 foil and raised the motor by one hole (about 25mm).
It is absolutely amazing the difference it has made.
Three weeks ago I was ready to sell my boat, thinking I had made a terrible mistake.
Now I don't know that I will ever part with it.
Now, at take-off the bow only raises, so from the tiller you can only just see over the bow and on the plane I have to trim the motor out a fair way to get the optimum ride.
I really can't express my gratitude enough to all those who took the time to assist by offering advice.
I owe you one.
Thanks guys!