Merc porting

[K-Dawg]

Can a stock 2.5 150 Mariner Mag III be sent to someone like Jay Smith, Jonh Marles and Have the block worked to 200, 225 specs? Or is in cheaper to buy a new, Rebuilt power head.If so, Will the stock carbs work if jetted? Will the stock electronics work? Thanks for any info.

[SSTOM]

Yes the 150 can be turned into a 200 or a 225. The thing is that the 150 has small ports in the cylinders that loose compression. Depends on what you want to do with the motor. Jay or John can tell you more on the block. The stock carbs and eletronics will work also. Hope this helps Tom

[David]

I would expect a drop on or just a motor swap would be the least expensive approach.

[us1]

Sure you can. I get them well into the 300HP range. Make sure it has finger ports. The early 2.5 150s did not. I think the Mag III all did though. What year is it?

[K-Dawg]

It's a 1994 Matiner Mag III. Would it be cheaper to go through this one or just buy a drop on? Only want a 225. But this is just pre-planning so I will know what my options are. Thats for any advice. I was hoping you or jay would find this post and clue me in.

[us1]

All you have to do is change the port timing and richen up the fuel mixture to get 200 or 225 HP. It never hurts to take apart a motor and check everything anyway. New rings and gaskets are always nice.

[K-Dawg]

Well, I am certain I will be buy a T-4 in the near future and all I have for power is my Mag III. I know I will need more power. Can't afford new boat and motor so, I was trying to figure my best option money wise. Sounds like I'll be sending a motor your way in a few months.

[us1]

Send it on over.