Need help with 2.5 ss Merc 2005 model

[marcw31]

I am looking to buy a year 2005 2.5 SS which has low hours but the owner says he removed the exhaust (there is a big trapezoid hole where i guess it used to be just above the lower unit case. Also the guy said he had a computer mod done to extract another 100rpm or so which i think will get it up to 8000 +/-. Is this stuff good or bad and what do you all think about this motor when in good condition. I plan on putting it on an 18 Liberator. Any guesses on top speed with a 27P prop? Thanks
MArc
:cheers::cheers::cheers::cheers::cheers::cheers::cheers::cheers::cheers:

[WILDMAN]

8000 rpm with a 27 will put you at 100. You'll need a bigger prop for topend. Why people hack up a perfect motor just to make more noise, I'll never know. I'd say that big hole just made it worth at least $ 2000 less. It definitely will not give you more power! Unless you can get it for 10K, I'd stay away from it. Just my opinion though.

[Raceman]

Good condition makes a LOT of assumptions. You should at the minimum have a compression test and leakdown test done, and then it's a crapshoot. If I were buyin' a used motor I'd do the two tests AND THEN if I wanted it and the price was agreed on, tell the seller that I would buy it subject to pulling the heads for a good look at the cyls............. but maybe that's just me. Anyone who would have some computer model done for exhaust relief should probably stick to computers and have somebody with some MINIMAL knowledge of outboard motors do the modifying.

As far as the hole in the exhaust giving it another 100 RPM's.....:icon_bs:

RPM is more a function of setup/load/prop/gear ratio. If you want to turn it 8K, I'd have to ask WHY. It will: 1. shorten the life 2. make it more prone to mechanical failure 3. make it use more fuel 4. accelerate harder (get from 0 to X MPH quicker) 5. run slower on top end.

Unless you're drag racin' it you'll be better off throwin' the pitch to it.;)