HPBCANADA.COM

A ported one will rev like a common HP merc (i.e not some crazy drag). My 225 spun like a ProMax but you can feel it run out of power past 6500 and I didn't like turning 7k with my stock oil injection either. My stock motor with a 32 Cleaver ran 93@6100...you need lots more power to swing a big prop with gear...

Back to the question at hand...parts swapping...apparently you can bolt a Yamaha ignition system on to a slOMC...

Yamaha power tilt/trim tech question: I recently picked up a Yamaha Pro 50 with a power trim unit that I was hoping to use on a 3 cyl OMC short shaft "Yamarude". The power trim unit is functional it tilts the motor all the way up and will trim almost all the way down but once the 2 trim pistons bottom out, the tilt cylinder starts to raise the motor again even with the trim switch in the down trim position. I have checked and serviced the oil level and bleed the air but no fix. Has anyone experienced this before or suggestion on where to begin troubleshooting??

It is surprising how so many parts interchange with the 30, 40 and 50 yamahas. We all like the 3 ram power trim units on the Pro 50 motor. The older 40 and 50 hp small single ram units are not suited for our yamaharude trim systems, but, you can use that trim with its clamp bracket and it bolts right on the 30 hp. You can switch the harness to the 10 pin. Switch over the trim relays and you have a factory setup that is very light and the trim is strong enough to handle the 30 hp. I don't recall factory trim available on the 30 hp.
Nice unit to have on a short shaft... Work perfect on your GT30 racer.

Old thread, but on thanksgiving weekend I had a chance to switch a lot of 30 and 40/50 yamaha parts from motor to motor.
The 30 hp lower units are longer than the 40/50. There is extra space above the plate.

So here is what fits and what did not fit.
Pro 50 power trim bolts on the 30.
The 30 lower unit and 40/50 lower are interchangeable.
The pans & cowls are not interchangeable.
The carbs and read cages are interchangeable.

I never liked the look of the 30 short shaft because of the lower unit. The 30 short is over 15 inch because of the gear case
I put together a 30 short with:
pro 50 trim
50 lower unit
40 hp carbs
It looks perfect. Great motor for a Tom Cat tunnel of small SLT.

Our Scout has a pro 50 long shaft which has to be jacked 2 inches above the transom. Looks terrible!
I made it a 50 short shaft and used a short shaft 30 lower unit.
Now the motor sits flat on the transom and looks right.
I will need to get a prop made because of the difference in gear ratio if the 14 pitch is too small.

Andrew, I didn't think to try tiller parts. I bet you can switch any of them provided they bolt to the steering arm on the motor. The push and pull shifting gear cases would not be a problem. Those shifting parts would bolt in the pan.