115 hp Mercury Optimax/how do I increase hp?

[boblmart]

How do I increase the horse power on a 2000 Mercury Optimax 115hp? Where can I get the parts (computer chips etc.) necessary to do this? Is this an electronic/computer chip job? Thanks.

 

[JB]

Re: 115 hp Mercury Optimax/how do I increase hp?

No, Bob, it isn't a chip swap or a jet swap. It is a BIG bux swap. It would be cheaper to swap for a bigger engine.<br /><br />The most usual differences in engines that look the same to the non-engineer are port timing and exhaust design. You might also find higher compression, different reeds or reed plate, bigger throats in the air intakes, different chip(program) in the ECM, different pistons, etc, etc.<br /><br />Myths persist that by doing some simple, inexpensive adjustment or part swap, higher HP can be achieved. Most of these are just that: myths. Believe me, Bob. If it were that simple someone (Edelbrock?) would be selling kits to do it.<br /><br />Tune up your prop and boat for more speed and/or hole shot. Cheap, reliable, bolt-on horsepower increase is NOT available for 2 stroke outboards.<br /><br />Red sky at night. . .<br />JB

 

[DJ]

Re: 115 hp Mercury Optimax/how do I increase hp?

J.B. is right. Even though displacement may be the same, there are mechanical differences. In your case it is probably at least injector capacity and pulse width.<br />Also, higher horsepower engines of the same make with the same displacement tend to turn up higher rpm's.<br /><br />With todays electronics it is ever more difficult to bolt on horsepower.

 

[rap]

Re: 115 hp Mercury Optimax/how do I increase hp?

the 115,135,150,175 HP Opti's all share the 2.5 L block. A parts list comparison would be a good start. As you can compare what parts are different. I would be willing to bet there are fewer differences in major components than some might think. Making several models of major components is not very cost effective in todays world. I'm sure the major differences in these engines are bolt on items. However thats not going to make it any less expensive. Your can bet that merc has made this type of upgrade difficult. After all how could they justify charging you several thousand $$ more for the same engine thats simply tuned differently. As if it cost them more to build a 175HP vrs. a 115HP version of the same basic engine. If you were merc or any manufacturer wouldn't you want as many model engines from the same basic engine as you could. basic manufacturing 101 says the higer the quantity the lower the cost. Its the age of the computer govenor.

 

[trevorcday]

Re: 115 hp Mercury Optimax/how do I increase hp?

We have done this exercise on several new Mercs. Unfortunately I have not done it on this particular engine. The thing to do is compare the parts list on the Mercury electronic parts catalog (which any Merc dealer will have) between the two engines in question. Identify which parts are different and price them out. It is seldom cheap but you would probably be taking a big hit to trade in your 115 also.<br /><br />Boblmart; if you would like to know exactly what you need, e-mail me your serial number at trevorcday@hotmail.com and I will figure it out for you.

 

[ODDD1]

Re: 115 hp Mercury Optimax/how do I increase hp?

Why, bob? so you can spend a grand on maybe the right stuff, maybe get the power you want,when something does go wrong, maybe get it fixed [Weeell, it used to be a 115, but i changed this stuff] trade it off for the motor you want, you will be farther ahead and richer in the long run...

 

[trevorcday]

Re: 115 hp Mercury Optimax/how do I increase hp?

I was curious so I checked. The differences between the 2000 115Opti and 150 Opti are as follows:<br />Reed blocks<br />Throttle body<br />Exhaust pipe<br />Throttle cam<br />Engine computer<br />Lower unit gear ratio<br />A lot more than just dial-a-horsepower in the ECM.

 

[down_time_1]

Re: 115 hp Mercury Optimax/how do I increase hp?

bob, i bought a 115 opti from bass pro cinn ohio in march 2002 (new floor model). it's been in shop most of last season , till sept 3 2002. how has yours been? thanks,Paul DuLaney pdulaney@main-net.com

 

[miloman]

Re: 115 hp Mercury Optimax/how do I increase hp?

Bob the old saying goes if it aint broken dont fix it. I think that the others hit the nail on the head. Reprop it you mihgt gain a few hundred rpm better hole shot etc... but i think unless you can build the motor from scratch and have done it onseveral occasions I would pass. It will end up costing you more then the upgrade. Sell your motor get the money take a bit for the difference in the long run I think it will be better

 

[RJS]

Re: 115 hp Mercury Optimax/how do I increase hp?

The emission standards make it illegal to tamper with your engine to get more HP.