Tweeking a 1993 120 Hp to 140 Hp

[bgiles]

Hi guys, I have a 1993 Evinrude 120 Hp which from what I have learned is the exact same block and setup with respect to cu inch, bore , stroke and general setup as a 140 Hp.<br /><br />Has anyone had experience in "tweeking" this motor to gain that extra 20 Hp. Based upon a little bit of investigative work via other posts etc, it appears as if different "reeds" are probably used and perhaps some modifications to the intake and exhaust side of things.<br /><br />Any words of wisdom would be appreciated, always looking for ways to gain that extra mph or two !!<br /><br />Not sure I'd want to do a complete rebuild but if it only involved some minor swap outs, I'm in.<br /><br />Thanks in Advance<br /><br /><br />Bruce

 

[Brew2]

Re: Tweeking a 1993 120 Hp to 140 Hp

I'm sure others will come along that know more, but....<br /><br />I'm pretty sure the 140 has a different set of carbs that have a larger barrel to let more air in. Don't know what other mods would have to be made, but as a minimum I think you would need to swap out the carbs.<br /><br />Good luck!<br /><br />Brew

 

[WillyBWright]

Re: Tweeking a 1993 120 Hp to 140 Hp

You can swap parts and hope for 140Hp, but I believe the blocks are ported differently. That pretty much is a deal breaker.

 

[Dhadley]

Re: Tweeking a 1993 120 Hp to 140 Hp

The blocks are the same. The powerhead part numbers are the same. The carbs were the only thing different but I doubt if youll see any difference worth the $$$. Thats why in later years they eliminated the 120 and 140 and just called it a 130. <br /><br />Concentrate on your set up. Max it out. Spend money on a prop when the set up is maxed out. <br /><br />Tell us more about what boat, prop and set up you have now.

 

[bgiles]

Re: Tweeking a 1993 120 Hp to 140 Hp

Thanks Guys, Dhadley my current setup is a 13 1/2 x 22 Raker running at 5800/5900 rpm with a gps speed of 53 mph trimmed out to the maximum. The boat is a 1992 Checkmate Pulse 170. <br /><br />I have a 6 inch setback jackplate that I'll be putting on in the Spring time which may buy me another 1 mph or so, at worst it should handle a little bit better. Currently the cavitation plate is approximately 2 inches above the pad so there is a little bit of room to go up to the 3 inch mark.<br /><br />I have too much time on my hands with all this snow kicking around. Once I get the jackplate on I figure that I've done as much as possible without going overboard on $$$$'s.<br /><br /><br />Again, thanks for the information !!!<br /><br /><br />Bruce

 

[Dhadley]

Re: Tweeking a 1993 120 Hp to 140 Hp

Nice ride!<br /><br />Your just under 15% slip. Not bad but it can be better. Checkmates tend to have a pretty fair hook in the hull. That gets them on plane quick and helps make a great ski boat but it may never air out like an Allison or Hydrostream. <br /><br />Thats a pretty good prop. The jackplate will definately help. Dont be afraid to turn the motor. When you get that prop to hit the limiter, we'll just get a bigger prop. No big deal.

 

[bgiles]

Re: Tweeking a 1993 120 Hp to 140 Hp

Dhadley, thanks for the vote of confidence, as you say, let's see what the jackplate brings us and we'll go from there.<br /><br />Thanks Again<br /><br />Bruce

 

[Dhadley]

Re: Tweeking a 1993 120 Hp to 140 Hp

Sounds like a plan. Keep us posted!