Big Block Billy

Yes if running alpha's, swap lower for counter rotation and move cable in box to make it shift backwards.
If running bravo just move the cable in the box. That's it.
If you really need some counter rotation parts for the 350 I have them, cam's gear drives etc... BBB

Alessandro

Hello everybody,
I'm writing from Italy and I have more or less the same problem: I do need to invert the rotation of a Merc 5.0L MPI of 2002 which is one of the two the engines which refits an old Riva boat. The problem is that I'm obliged to do so because the trasmission is a V drive and I can't change just the inverter as new Velevet models doesn't fit with the existing Vdrive and the old one can't work in reverse over 2,000 rpm.
In other words when the previous owner refitted the boat didn't realised that he needed a right and left engine and just installed two lefts. The result is that both propellers are turning counter-clockwise...
How many parts needed to be changed for modifying the rotation?
Thanks!
Alessandro

picklenjim

Why can't you just leave it that way? I know of several boats around here running both props the same rotation. It would be a big expense to go through unless it's absolutely necessary. Basically would have to get a counter rotation short block.

ezstriper

most all of the reverse engines are inboards...and they no longer do that...done in the trans....but there still lots out there...I have a newer one in my gibson....had no choice...can reverse a 72c trans like newer ones...but no big deal to switch back...the pistons may or may not have been swapped...whoever the marinizer was who did the engine would have done that..seen then done and not before..put a head and see if the notches are in the front or rear ?

Alessandro

Well with both propellers rotating in the same direction the boat looses efficency in particula at high regime and generates turbulences. The trasmission is in front and sent back with vdrives.
You know this is an historical boat and should be equipped as in the origin otherwise moves from historical to old...
Maybe the only solution is to try to sell one engine and rebuy a regenerated one.

rjr

I used to have a Bayliner with both motors going the same direction. Not talking a lot of power but the only problem I had was that you could not let go of the steering wheel without turning.

Mbam

It is possible to change on of your existing V drives to chain instead of gear. What is the number on the V drive tags?

Alessandro

It' Velvet Drive V 71C (year 1973).

picklenjim

That would probably be the best solution.

vdriven

If you are running this with a Mercruiser alpha drive, it would be a lot less screwing around if you remodel your outdrive to turn L.H. ?? Or even run them both R.H. if you have power steering on it as I am sure you do, you wont have much of a torque problem anyway. Good luck