Help identifying my steering cylinder

[AQUADJ]

I have a 1990 Blackfin Combi with 1998 Yamaha outboards. I'd like to add an autopilot and need to know the c.i. the steering cylinder pushes. The original steering system is by Hynautics and I believe the cylinder is original but because the motors have been changed the cylinder may have also been changed. There are no markings on the cylinder and all information I've found regarding the Hynautics company does not give dimensions. The cylinder matches a schematic of a K10 series. Does anyone know the dimensions?

 

[F_R]

Re: Help identifying my steering cylinder

A K-10 mounts in front of the engine, between two arms, and connects to the tiller arm by way of a slider plate arrangement. Sound familiar? It is 1-1/4" bore x 9-1/2" stroke, displacement is 7.5 cubic inches.

 

[AQUADJ]

Re: Help identifying my steering cylinder

Thanks for the reply. That information sounds correct but I'm not sure how the stroke is measured. My cylinders including the ends is 13.5" and the remaining rod through the cylinder totals 11.5" for a total length of 25". I was told the K10 cylinder is 9.5", if each end is 2" then my 13.5" cylinder would match.

 

[F_R]

Re: Help identifying my steering cylinder

Stroke is measured by steering all the way over in one direction, measure the rod sticking out, then steer all the way over the other direction and measure the rod sticking out (same end). The difference in measurements is stroke.

All this of course assumes your engine allows the cylinder to travel through it's entire stroke.

Overall width of a K-10 is listed as 25.6", which includes the hex head bolts on the end of the rod, according to the picture.

The main feature of the K-10 is the slider plate bolted to the top of the cylinder ends, with the rectangular hole that the Delrin slider block works in, with big washers top and bottom. If it has that, it's a K-10.

 

[AQUADJ]

Re: Help identifying my steering cylinder

Thanks again, that information confirms my system is a K-10. The slider plate is exactly as the schematic shows and the Seastar is completely different.