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Thread: Convert Mercury 25hp to a 30hp
11-10-2007, 09:42 PM #1
Convert Mercury 25hp to a 30hp
I just bought the 2007 Mercury 25hp outboard with batteryless EFI. How do you convert it to a Mercuy30hp. Where can I get a stainless steel prop for this new motor.
11-10-2007, 10:24 PM #2
OK, up to my 02, i don't think that you could increase the HP to this extent BUT i've seen miracles happen every days ( laugh )
As for the prop, i believe that your dealer could set you up OR the trade and Sale on this forum could be an option...Glastron GT 150 W OMC 140
Glastron GT150 w OMC 235
Hydrostream Vision with 2.0l 135
Hydrostream HST w 3.0L 225
I know two things that are infinite, the Universe and Human's Stupidity, although I am not sure about the first one.
11-11-2007, 03:10 PM #3
One way would be to go through the parts manuals and see what's different. Same bore and stroke, so the short block is likely the same. Could be porting, valves, camshafts, all of the above.
11-12-2007, 01:22 AM #4
11-12-2007, 01:23 AM #5
11-13-2007, 05:33 PM #6
11-13-2007, 07:00 PM #7
2007 motor? Isn't it still under warranty? A change like that will completely void all of the warranty
I think current EPA rules would require any shop to return it to all original configuration if they have to work on it (if anything breaks in the future).
12-02-2007, 08:04 PM #8
The Two motors are the same. The only difference is a spacer infront of the carby which limits air flow. Go to a Mercury dealer and get it taken off and swapped for a 30hp spacer. I have had two of those motors and trust me 5hp makes a big difference.
Does it void the warranty? im not sure.
01-19-2008, 02:36 PM #9
Doubt you can make it a 30hp...
The 2007 25EFI Mercury (Tohatsu) is a digitally fuel injected 4-stroke and you would need to have the computer changed to make it a 30hp... The 30hp Mercury (Tohatsu) computer would cost you more than just selling your motor and buying a 30hp...
01-18-2009, 11:51 PM #10
port and polish the intake ports and throttle body. i gained 2mph by doing this. I plan on doing this to the head soon see if i can gain 2 more mph.