I installed Marine Machine external steering on my '89 F311SR1 with Silent Thunder platform. It did not hit when trimmed up to trailer. Their steering system uses wing plates. I flipped mine over to lower the attachment point. Used the drive shaft location (X) for vertical location of rams. After that it was mock up and look at everything with drives trimmed and turned in various combinations. Yes one SS braided hose did rub one corner of the inside of the center pod of the platform. The handling difference is enormous. Do not do the outside only type of system, go ahead and do the full system from the helm. Good luck, Joe Murray.

I have IMCO on mine and it works like a dream, its a bit close and i broke a line, but easily fixable, just dont crank the wheel when in trailer mode or totally timmed up (learned the hard way) but learned none the less. I have silent thunder as well...Rob

The pic is of the drives in trailer with the shrinkwrap pulled away, so that should give you an idea.

Perfect!

I been looking at the Hydraulic also ...anyone know if I could go Hydro from helm back to internal ram ....and then maybe next year go external ? Cuda ... I saw a thread where you guys were talking about using both pumps ...seems it was a year or so ago ....

mopower, I have hydr external steering on my 272SR1 and it won't hit if the drives are straight. I used the IMCO system with the rams installed in between the drives. The photo attached is without the Silent Thunder however I initially had it on with it. My initial plan was to taper the inside corners of the center section of the ST platform however when it didn't hit I just left it alone.

From memory it was very close with the stringer for the bolts but I can take measurements for you if will help.

By the way how fast is it?

Ian T.

Cay, Thanks for the advice. Since a number of these will work ,it'll come down to price more than likely. Except for Imco there guarentees tend to suck.

How fast is it?...well , 80 untrimmed and still had throttle. Try to bring the trim up and it starts to get real squirrelly . I got to keep a lot of boat in the water to go straight. Get some steering and trimmed up , next season could see 85 maybe 90. Oh yeah , I'm adding Canfield Aluminum heads this winter too. My Merlins are too big and the port velocity is too low to get a good charge unless I spin them to the moon.

Talked to Imco yesterday ....3600 or 4200 with tilt wheel .....Ouch !

I want to keep it under 3500 if possible...and I mean as far under 3500 as possible

I only did the add on system so it wasn't quite so expensive. I notices the greatest improvements in stability when I replaced my gimbals, make sure they are very tight. Even so you are in for a fun ride. I run 93 with just about neutral trim, full fuel and two people.

What was your final HP? Have you considered modifying the ST platform and installing some other kind of noise control? I picked up 7mph when I removed the ST platform and I am sure it was from exhaust improvements. I am convinced that my exhaust and carb are limiting my HP.

Last years hp was 638@5800