Mermaid Meteor II throttles unbalanced

[Robojl]

We have a Seaward 23 motor cruiser with her original (1989) twin Mermaid Meteor II engines - based on the Ford XLD418. The morse MT3 dual function control levers are balanced at tick over in neutral but as you put the engines under load the starboard throttle has to be ahead of the port to achieve the same RPM (about a cm).

It's not a throttle cable length issue as they are balanced at tick over - my suspicion is the governor spring on the engine needs adjusting. Has anyone had a similar issue and knows how to adjust it?

Thanks in advance!

 

[burgundyben]

Maybe one prop is a bit more load than the other?

I chased a similar thing on a biat for years and gave up.

 

[kashurst]

Could just be play/stretch in the throttle control/cables etc. A cm worth of movement at the throttle lever end isn't much to build up over the length of all the cables etc. Have you measured the injection pump throttle lever movement at the fuel pump with the engines off, in neutral and at different positions forwards? Could just be something loose/bent somewhere in all the gubbins. If everything is exactly the same, try disconnecting the prop shaft coupling and with the engine running, see where the levers need to be to create equal rpms.
I wouldn't touch the fuel injection pump if everything is otherwise in good order. You could make things a lot worse.

edit why do we call the levers throttles? There is no throttle, the levers set the desired rpm.

 

[QBhoy]

Fairly normal thing that you could put close to right, with a fair bit of footering….
But can I just add that the thought and logic mentioned around it not being a cable issue, may be a little inaccurate. I’d think that when the engines are at an idle speed, there isn’t usually any influence or load on the cables. Only when throttle is applied, will the cables take up and come under any strain or load. One cable may be stretched a little.
Regardless, there can be slight adjustments made at either end perhaps.
I might also add, that there is very often variance between two engines, their analogue tachometer reasons…and the actual true rpms of the engines. Not sure I’ve ever been on or driven a twin engine boat, that will truly have their engines in sync, by using the tachometer value as a reference to achieve it.
Anyway…somewhere between or amongst the above, lies the answer. Hope it helps