2002 Mercury 40 EFI 4S Big Foot to 60 HP?

TinBoats.net

Help Support TinBoats.net:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

RedHatRedNeck

Well-known member
Joined
Mar 31, 2017
Messages
143
Reaction score
0
Location
Centerview, Missouri
Curious if anyone's ever taken a 40 and turned it into a 60? What all did you have to do? How much did it run? Performance before vs after? Thinking since the manual for my 40 has the 40, 50, & 60 it can be done? Not the most mechanically inclined so any input appreciated.
 
https://www.boats.net/parts/search/Merc2/Mercury/40%20EFI%20%284%20CYL.%29%284-STROKE%29/0P153500%20THRU%200P400999/Cylinder%20Block%20and%20Crankcase/parts.html

https://www.boats.net/parts/search/Merc2/Mercury/50%20EFI%20%284%20CYL.%29%284-STROKE%29/0P153500%20THRU%200P400999/Cylinder%20Block%20and%20Crankcase/parts.html

Not sure if that's your 40hp or not, but to know for sure you'd better go part by part through the block & crank case diagrams fuel system and ignition component diagrams to start with. It looks like they both use the same part # for the complete cylinder head and intake manifold assemblies, which is a good sign that much will be the same.

Actually - looking quicky - they appear to be EXACTLY the same engine only the 40hp & 50hp models have a restrictor (part #24 in the intake manifold diagram) I would imagine if they're using the same fuel injectors and same throttle body assemblies with only a restrictor to make differences in the airflow then the computer unit (ECM) controlling the injector pulse and ignition timing would be the only other difference they *should need, but I'm not going through all the diagrams to be certain.
 
Is this one the Yamaha powerhead or the mercury powerhead? Yamaha made all of Mercs powerheads in the beginning. They found out real quick that the 40hp had the plate in it and everyone was taking it apart and removing it. Can't remember when, but they stopped using the plate and went into the ECM to change the program to make the different HP.
 
onthewater102 said:
https://www.boats.net/parts/search/Merc2/Mercury/40%20EFI%20%284%20CYL.%29%284-STROKE%29/0P153500%20THRU%200P400999/Cylinder%20Block%20and%20Crankcase/parts.html

https://www.boats.net/parts/search/Merc2/Mercury/50%20EFI%20%284%20CYL.%29%284-STROKE%29/0P153500%20THRU%200P400999/Cylinder%20Block%20and%20Crankcase/parts.html

Not sure if that's your 40hp or not, but to know for sure you'd better go part by part through the block & crank case diagrams fuel system and ignition component diagrams to start with. It looks like they both use the same part # for the complete cylinder head and intake manifold assemblies, which is a good sign that much will be the same.

Actually - looking quicky - they appear to be EXACTLY the same engine only the 40hp & 50hp models have a restrictor (part #24 in the intake manifold diagram) I would imagine if they're using the same fuel injectors and same throttle body assemblies with only a restrictor to make differences in the airflow then the computer unit (ECM) controlling the injector pulse and ignition timing would be the only other difference they *should need, but I'm not going through all the diagrams to be certain.

Thanks! I have th service and repair manual just haven't made it all the way through the 600+ pages yet.
 
tomme boy said:
Is this one the Yamaha powerhead or the mercury powerhead? Yamaha made all of Mercs powerheads in the beginning. They found out real quick that the 40hp had the plate in it and everyone was taking it apart and removing it. Can't remember when, but they stopped using the plate and went into the ECM to change the program to make the different HP.

Couldn't tell you which one it is.
 

Latest posts

Top