Hynautic Helm Pump
 

Hynautic H-21 helm pump.
$150/offer

http://www.go2marine.com/product.do?no=81264F
http://i43.photobucket.com/albums/e3...h_IMAG0131.jpg
http://i43.photobucket.com/albums/e3...h_IMAG0130.jpg
http://i43.photobucket.com/albums/e3...h_IMAG0129.jpg

Would this be for a single ram (single engine) or twins? What would be required in addition to this helm pump to convert a boat that has "hynautic" (cable to transom, then hydraulic assist) to full hydraulic?

You would need external rams, Pressure Reservoir, relief valve or a Hynautic Reservalve that combines both. You can find them on ebay or I have seen a couple in the OSO swap.
http://teleflex.ru/upload/files/cata...d-Hynautic.pdf

So if the boat already has external rams fed by the power steering pump, would you eliminate the power steering pump in a full hydraulic system? In other words, you turn the drives by hydraulic pressure without using a mechanical pump to assist you?

Sorry for the dumb questions.

No dumb questions. The helm is an actual displacement pump (I think it is ~1000PSI). You disconnect your steering pump and cylinder from the back and plumb directly to the cylinder with the Reservalve in place. These are used more in outboard application then I/O cause they lack the power steering pump. I did have it on my I/O though.

Ttt

TTT
offers?

is the h-21 pump still available from rookie? Thks!

Yes, pretty sure it is still sitting out at my shop.