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bigman
03-08-2002, 09:02 PM
I am repowering my 18' 2+3 with a new 350mpi Merc Mag, Bravo 1 outdrive. I had a 315W Ford with a Volvo 250, no powertrim. Does anyone have any advice about reinforcing the transon, what prop to use, or what kind of performance I might get from this setup? Thanks for any help, Bigman.

Ralph Savarese
03-08-2002, 09:19 PM
Hi ,
You can reinforce the inside with 1/4" aluminum diamond plate But more importantly be sure the transom core wood is still good. With a Donzi's that age it might be a wise idea to install new transom and or stringers. I went to aprox the same power range you are running but stuck with my Volvo 270 for durability purposes .I saw an increase of about 5 mph from a 302 . I may not be the fastest but other Donzi members who have seen me know I do keep up with them. I Would safely say with the 350 about 350hp or so you should see 65mph
Ralph

CDMA
03-08-2002, 10:36 PM
I agree with Ralph. At that age it probably is time to take a good hard look at the transom and stringers. I did the mercruiser swap on my 1968 18 and rebuilt the transom. It really was not such a bad job and it looks very professional. My guess is with a 350 mpi you will be very close to 70. Spinning either a 23 or a 25 mirage or similar. Also make sure you set up the Bravo to spin left hand. The 18 does not like a LH helm and RH rotation. Tends to lift the starboard side if the driver is alone. For this reason I am currecntly swapping a RH only alpha for a dual directional Bravo.

Best of luck. Anything I can do to help e mail me.

Chris