2001 Merc 90hp tiller

[marsh hen]

I just finished building a 40hp yamaha and felt like it did not have quite enough. So, i started looking and found a good deal on a 90 Merc. I have never messed with a merc before. Where should i start to get the most out of this motor? Its going on a 17 ft 56"WIDE HAVOC jon boat. Boat weighs about 380 pounds.

Thanks for any help i can get with this motor.

[marsh hen]

come on, need some help. New to site and i have seen where some of you can make the 59ci mercs fly. Just would like some starting points, reeds, tuner, etc. Whats a waste and what is worth modding.

Is the 90hp that much different than the 59ci?

[omcstratos]

Is the 90hp that much different than the 59ci?

Weight, gear ratio, midsection length, exhaust hub diameter. Those are some of the main points.

As far as modding your motor, what kind results are you looking for?

[marsh hen]

looking to wake it up a little. Dont need a fire breathing monster, but like to hear the motor some. Would like to do about everything i can to it but go inside the crank. The motor has less than 50 hour on it and you can eat off of the side of it, super clean. Does cutting the exhaust with the mercs a good idea? Other than reeds, is there anything else that can be done? with the head welded on like Mercury likes to do. Is it a good idea to mess with the timing?

[tyst67]

looking to wake it up a little. Dont need a fire breathing monster, but like to hear the motor some. Would like to do about everything i can to it but go inside the crank. The motor has less than 50 hour on it and you can eat off of the side of it, super clean. Does cutting the exhaust with the mercs a good idea? Other than reeds, is there anything else that can be done? with the head welded on like Mercury likes to do. Is it a good idea to mess with the timing?

Id love to have that motor :) the 75 and 90's are basically the same motor so make sure your motor has the big carbs and reed cage! You can port them, custom reed cage, advance timing an a few other things! Pm me and we will talk

[omcstratos]

As far as cutting the exhaust, all it will do is make more noise. No big performance gains, but in some cases you will run a little lean.