93' Evinrude rebuilt

Joined
Feb 23, 2010
Messages
62
I just had a new engine installed on my boat, a rebuilt 93 Evinrude 50hp. Right now I'm running a double oil/gas mixture (25:1) in order to help break it in, as per the installer's instructions. What I want to know is if I'll gain anymore top end speed when I switch back to a 50:1 mixture? The reason I ask is this engine doesn't seem as fast as my old engine, an '89 Force 50hp. The marina even said this engine was bored over slightly so should have a little more than 50 pony's. Any input?
 

waynehol

Petty Officer 3rd Class
Joined
Jun 4, 2009
Messages
88
Re: 93' Evinrude rebuilt

Running rich fuel should not decrease performance very much, at least not during the break in period. It will smoke more. When you switch to 50:1 be sure to clean and or replace the plugs if needed
 
Joined
Feb 23, 2010
Messages
62
Re: 93' Evinrude rebuilt

Thanks for the input. Could you (or anyone) offer some possible explanation as to why this engine is running slower? Will performance increase once its finally broken in or no?
 

HybridMX6

Senior Chief Petty Officer
Joined
Oct 22, 2008
Messages
676
Re: 93' Evinrude rebuilt

could be a matter of getting the proper prop on it. You will need to post your current prop info, and perhaps your old prop info from the other motor if you know it, in the prop section, and they can let you know better than this part of the forum.
Did the installer tell you that you could rev it to max rpm while under the break in period? Just curious, I've never done it before, but have heard you always go up and down in the rpm curve, never staying at one constant rpm, for long enough to achieve max speed anyways. More like a bunch of short bursts all over the rpm band.
 
Joined
Feb 23, 2010
Messages
62
Re: 93' Evinrude rebuilt

They said 2 constant minutes max at WOT. I think I've been doing a pretty good job of varying speeds. I'll get on plane then back off to 3/4 then back to full then down to 1/2, then idle then 3/4 etc..etc..

I'll check all the prop info out and post in the appropriate forum thanks!
 
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