What breaks in stock steering that necesitates hydrolic steering? Are add on systems as strong as full hydrolic?

Add-ons are just as strong as full, just not as easy to turn at idle speeds. The tiller arms are a weak point.

The stock steering system has too much play for high speeds causing erratic boat handling. Hydraulic steering supports the drive better.
Sincerely
Dennis Moore

I like that last answer. Gets right to the heart of it!

BT

Thanks Dennis, thats kind of what I thought. I drove a high power cat last summer with loose steering, pretty un-nerving at 90+.
OBTW, I enjoyed your BBC book, excellent info, well organized.

What is the practical speed limit for the Merc steering. At what speed does it get "too loose" for the conditions?

I think Merc recommends 70 mph and faster.

A simple thing as the Powersteering BELT breaking will throw you for a loop.

A hydraulic steering system will prevent the drives from flopping to one side and turning you into a circus act.

I would imaging twins with counter rotating props would diminish the circus act potential significantly. My power steering pump was toast most of last year. Only real issue was slow speed manuevering. I don't touch the steering wheel then anyway due to twins, so It doesn't much matter to me.

BT

BT,

Twin counter-rotating props WILL flop .... take it from me, been there ... it took everything in my power to stay in the boat. I definately had NO control over what was happening at 70 mph in 4-footers.

I believe it's the steering valve that uses pressure to turn one way and the relief of pressure to turn the other way. Well, with no pressure, things want to turn one way or another.

I think the hydraulic-assist will hold the pressure in the cylinder to prevent the flop. But for sure, a full hydraulic will hold the position in the event of a pump failure.

G