Mariner 60 Bigfoot no trim when sailing

[DonPeterD]

Yeah, understand it if you can... The trim full up- full down, works flawlessly when in idle or even with the engine off. Could be faster I guess, but don't know how the speed is supposed to go at.

When I go 6 knots it's really slow at getting up.
When I go 15 knots or above, it goes NOWHERE! It just buzzes like an angry hornet!

I have tried to run it up- and down to bleed for air 5 times in a row, multiple times. I have refilled the cylinder with ATF fluid, and that help a tiny bit. What in the world is wrong??

Mariner 60 EFI Bigfoot 2006

[two stroke mick]

Was the unit empty when re filled. Is the movement of the engine smooth when trimming up if it is jerky it would suggest that there is air in the system that needs bleeding. Google bleeding ptt units

Tsm

[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)

It runs smoothly up- and down, when idle or off. Above 15kts it won’t go anywhere!

I have done the steps for bleeding for air, no luck.

[paintman]

It may be a design feature of the engine. One of the pdf manuals online says in respect to tilting up for shallow water operation:
"1. Reduce engine speed below 2000 RPM.
2. Tilt outboard up. Make sure all the water intake holes stay submerged at all times.
3. Operate the engine at slow speed only. If engine speed exceeds 2000 RPM, the outboard will automatically return down to the maximum trim range."

I can't give a link to it, but do a Google for 'Mariner 60 EFI Bigfoot 2006 manual' & you should find 'Brunswick Marine in EMEA Download Center' as a pdf.

[DonPeterD]

I’ve read the same thing, but it makes little or no sense, that trimming a running engine is not an option.

[paintman]

I read it as you should be able to operate the trim range within set angle limits but not beyond when engine revs exceed a pre-set maximum.

Is the mounting angle of your engine or where you've got the tilt stop pin(s) through the mounting that limits the down travel of the engine such that it's reduced the available trim adjustment range? Looking at the pdf the trim range - as opposed to the tilt - is quite small to begin with.

[DonPeterD]

It can be tilt.. see the video here

https://youtu.be/XDazXfEmY5g

can be tiltet down, over a point of complete uselessness! I'm going 4 and 8 knots here, at 8 it's clear, it somehow activates a bypass valve, that doesn't let it go higher. I'm not rugby-size, but with engine off, and my 100+kg on top, it doesn't give a f... it just FLIES up!
So.. I start to believe, that it is supposed to do so - but what the sweet mother of Joseph do I do, when it can't even trim past level, when sailing???

[9D280]

Im about to have to play Dad Taxi so this will be brief...

If you got the same gubbins as me the tilt phase is fast but no power to lift against the force of the prop.... you may also have a leaky seal inside the trim unit. Effectively playing like a bypass valve.

[DonPeterD]

Hi taxi dad
But why can it then lift itself AND me on top when off?
And when sailing, it can go all the way down and up - but only to a point of just under leveled out. If it couldn’t work against the force of the prop, I BELIEVE it wouldn’t go anywhere when sailing let alone with me on top?

Transom is angled in the order of 20deg back, that makes it closer to 30deg from level when it takes off and digs the rear down. I’m leaning towards the limited play it has, is within specs - but starting of with negative 25-30deg is somewhat of a lousy start!
I just can’t be the only one to have this problem??

[DonPeterD]

Ohhh cock...
So now what??

[beamishken]

Fit wedge shaped packers to reduce the transom angle

[DonPeterD]

That’s the first I thought - but is it really a liable option? I haven’t seen it anywhere.

[beamishken]

You can buy wedge sections for the purpose usually the other way around but shouldn't be a problem to install upside down

[beamishken]

https://www.specialistsmallcraft.co....transom-wedges

These won't go upside down but you get the idea it's something thats easily made maybe from a plastic material or wood or aluminium like these if you can get someone to machine the taper

[DonPeterD]

I do.
But how about Hotwirering the freakin limiter?? All zodiacs are build with a -20deg transom, Yamaha, Evinrude you name it, doesn’t have this god forsaken feature !??

[beamishken]

I doubt it's an electronic sensor more likely a bypass port with prv to avoid overload of tilt rather than trim

[uncle al]

How about either a bigger capacity battery? what is your tick over revs?

[paintman]

If the tilt mechanism of the engine is designed to work in that manner - and the pic he posted of the instruction manual says it is - a bigger battery isn't going to make any difference.
In the absence of a way of altering the engine's operation changing the mounting angle or replacing the engine would appear to be the only alternatives.

[DonPeterD]

It’s regulated by a spring operated valve. Above a certain force (2000rpm), the hydraulicoil flows past the valve, and it will not come up any further.
But it makes zero sense, every Mercury has this.. design fault!! So a new or other Merc isn’t going to help a thing.

Sooo why is it working for GA Marine here??
And why is it freaking straight level at that speed?

https://youtu.be/dKWBXlg9Vwc

[paintman]

Perhaps best asking them how they did it - or raising the matter with Mercury themselves to see what, if anything, they can suggest that would change things.

Can't see the 'design fault' argument. According to the pic of the manual you posted appears to be intended to avoid the engine lifting above a point which could cause serious damage to the engine due to lack of coolant. As it's an American company its possibly to reduce litigation/warranty claims from users who choose to ignore the warnings -even though under Warranty Information it clearly states that damage arising from that is specifically excluded.

The online manual also includes in a yellowy/gold coloured box
"! WARNING
Trimming the outboard beyond a neutral steering condition may
result in a pull on the steering wheel or tiller handle and loss of
boat control. Maintain control of the boat if trimming beyond a
neutral steering condition."
That box colour & caption is their "Indicates a hazardous situation which, if not avoided, could result in death or serious injury." So may be another feature to prevent litigation.

As far as changing the engine for something else is concerned you said in an earlier post the Yamaha, Evinrude etc don't have this feature so why would you want to buy another Mercury?