Macklin

I have a 2004 Concept CC with twin 250 Mercs that started wandering at speeds over 50 towards the end of last season. No other issues to that point. My buddy put his power bleeder on it, but did not correct it. The cylinders are Hynautic and titling helm unit appears to be Seastar. I spoke to the Seastar tech guy who gave me a test to do - tilt up motors and spin the wheel then measure for drop. I measured very little in either direction. Still he is not convinced it is the helm unit. Cylinders are not leaking and lines appear to be recently replaced. My buddy (long time marine mechanic) has never seen cylinders leak internally. Do I start there because the rebuild kit is $30 per side vice $350 to get helm unit rebuilt, plus shipping?

Thoughts or suggestions appreciated!

Tinkerer

When the boat is out of the water can you move the engines back and forth at all. They shouldn't move side to side at all.
If they do look for loose connections - it none then you probably have air in the system. Is the oil level proper in the reservoir?

Macklin

nope, nope, yep!

Tinkerer

Check your toe in or out depending on the direction of your prop rotation.

BUP

iTrader: (9)

Prob properly done for air in the system by your mechanic as it sounds like if he used the power purge - I know the power purge from Sierra / Sea Star Solutions / Teleflex --- so hopefully that whats you met by power bleeder ? -

Possible reseal properly as a leak or possible air entering ?? just adding some thoughts here.

Tiny air bubbles form even when filling the system or if the system HAS / HAD A LEAK or new parts installed or any fittings opened up -- they (the tiny air bubbles) in the hydraulic oil collect together - after sitting for awhile then form a bigger air bubble / air gap in the hydraulic system. Possible reseal --- Refilling and bleeding properly might help