Mariner 60 Bigfoot no trim when sailing

[beamishken]

If there is anyone guilty of a design fault it's got to be zodiac fitting transoms at the wrong angle all other boat makers make them fit the outboards not vice versa

[9D280]

This has moved on since my last read... and I've had a couple of vinos so apologies for any apparently daft questions.

So if I'm reading this right the thread has gone down the road of the transom being way too steeply raked for the Merc or any "standard" outboard?

....so how come no barrage of zodiac owners writing about the same problem? - let's make sure the engine really isn't at fault!

It can lift you.... But let's imagine you are somehow hanging on a rope which by a cunning arrangement of frictionless pulleys is pulling your boat along. Would that result in the motion you get at 2000 rpm on a 60? . Yes it's a test but the engine thrust will be a good order of magnitude more than your weight even trmined fully up.

If it's tucked under on start the downward angle of the prop will help to lift the transom.



Do you have a trim gauge? Does it move down when you open the throttle then stop at a certain point below which you need to "motor" it down or it self drops a lot more slowly?

Also do you have the single ran or the three ram type? Either way there is a low speed high force section for running and a fast low force section for lifting. Both setups change over and an internal leak can turn the "run" but into a "lift" and not have the power to resist the prop thrust.

The fact you topped it up might hint at a leak?

[chipko]

I’m with paintman here raised in post no. 6 regarding Trim-in stop adjustments.
Perhaps the 20 degree trim up range starts at the trim-in stop setting. If your transom has excessive negative angle resetting the trim-in stops might help.
Our Mariner 60 (albeit not Bigfoot) will power trim way above neutral at planing speeds and induce ventilation.

[paintman]

Originally Posted by 9D280

The fact you topped it up might hint at a leak?

Apparently not:
OP said:

Originally Posted by DonPeterD

It wasn’t drained - I just topped it off with fluid, 5-10% were missing. (Missing as it ran out, when I checked the level while mounted on the boat, transom is tilted 15deg. backwards, so it spills out

Think he needs to speak to Mercury/Mariner.

[Last Tango]

If it's a "three ram" system then quite straight forward. Get extension pieces machined to fit the ends of the two trim rams.
With the single ram presumably the cylinder travel determines where "trim" stops & "tilt" starts so it would be more complicated and there could be consequences at the top of the travel but still worth looking into.
BUT...you have to make absolutely sure it can't "trim" the engine beyond the bracket lateral supports.

[beamishken]

Messing with the tilt pin isn't going to help it only limits the amount you can trim in it won't allow you to trim out further
The problem lies with the angle of the transom 20°Is just too steep, fitting a wedge shaped packer is the way forward (or re fabricating the transom)
Anything you do to increase trim travel will bring you up onto the tilt part of the travel which isn't designed for the forces exerted during high speed use that's why it has a pressure relief valve (prv) to relieve excess pressure and avoid damage to components
You risk breaking saddle or brackets trying to get it to run on tilt travel

[Last Tango]

Originally Posted by beamishken

Anything you do to increase trim travel will bring you up onto the tilt part of the travel which isn't designed for the forces exerted during high speed use that's why it has a pressure relief valve (prv) to relieve excess pressure and avoid damage to components
You risk breaking saddle or brackets trying to get it to run on tilt travel

As I said,,,,you have to make absolutely sure it can't "trim" the engine beyond the bracket lateral supports but we're only talking about 5 degrees to "normalise" this. I'd doubt it's that intolerant or fragile.

[DonPeterD]

Really nice with all your replies - and I’m sorry for not checking in earlier on, but someone got me so drunk yesterday I have to leave this for tomorrow

[beamishken]

Originally Posted by Last Tango

As I said,,,,you have to make absolutely sure it can't "trim" the engine beyond the bracket lateral supports but we're only talking about 5 degrees to "normalise" this. I'd doubt it's that intolerant or fragile.

Why would you risk it when there is a far simpler solution though?