Steering problem Merc outboard

[RobSmythe]

I have an 80 HP Mercury outboard with hydraulic steering. The steering wheel turns the motor right and left easily when the motor is off, idling, or going dead slow. But at fast speed the wheel turns easily right, but I need two hands and a lot of muscle to turn it left. Trim problem? Lubrication?
-Rob

[Richard B]

Hi Rob, welcome to RIBnet.

I had exactly the symptoms you describe a couple of years ago. It turned out that I had a leak from one of the seals on the hydraulic ram (cylinder) at the outboard engine end of the steering. I guess that a leak or air getting into one side of the system at any other point would give you the same problem.

Look out for the helm pump oil level falling, or any signs of oil leakage (eg. rainbow patterns in the standing water in the rear bilge well). You may need to clean areas carefully as other contaminants such as 2-stroke oil can mask the presence of hydraulic oil.

[Alex Brown]

Hello Rob,

I would also check that the little fin under the 'anti-cavitation plate' (just above the prop) is in place, if it is, check the manual to see if it's pointed in the right direction.

For the first time ever yesterday, I saw a steering wheel block, the hydraulic pump bit of a steering system literally explode and crack into two sections. It made a loud bang and promptly deposited the contents within onto the deck of the boat and splatter a fair bit of fluid around the console area. In this case, the steering assistance system from the engine seems to have malfunctioned resulting in some significant feedback to the wheel.... thankfully it happened just 3 metres from the berth whilst the boat was barely moving.

Definately check your levels as Richard says though, and ensure that whatever you top up with is exactly what it says in the manual.

-Alex