Can You Turn a 40 HP Evinrude E-TEC Into a 60?

The Evinrude E-TEC 40, 50 and 60 HP are all the same engine. They run on the same two cylinder block, and the number on the cowl is set by the software inside the EMM, not by anything under it. That is why a 40 can become a 50 or a 60 through a reflash. The 40 to 60 step is the bigger of the two, and it is the one that comes with a single extra part: a thermostatic water valve. This guide explains why that valve exists, why the 40 to 50 step does not need it, and how the whole thing is handled.

One block, three ratings

On this small twin, the 40, 50 and 60 HP share the same powerhead, the same two cylinders, the same fuel and injection hardware and the same gearcase. The rating lives in the Engine Management Module. Evinrude loaded a different calibration for each power level and left the metal alone. Reflash the module with a higher calibration and the same engine makes more power, because it is finally running the map it was built around.

40 to 50 HP: pure software

The 40 to 50 HP upgrade is the simple one. It is a software change and nothing else: a gain of 10 HP with no extra parts to buy and nothing to fit. The same block runs the 50 HP map comfortably on the cooling hardware it already has. If that is the step you want, there is no water valve in the conversation at all.

40 to 60 HP: 20 HP and one part

The 40 to 60 HP upgrade is a bigger jump: a gain of 20 HP, roughly 50 percent more power. That is real, but it also means the engine is working harder at full throttle than a 40 ever did. More power means more heat, and the cooling circuit has to keep the engine at the correct operating temperature when it is pinned wide open.

Bear in mind that adding this much horsepower can mean your current propeller is no longer the right match. To get the full benefit you may need to fit a different propeller, and a dealer can help you size it.

Why the 60 needs a thermostatic water valve

Here is the difference in the metal. The 60 HP version of this block uses a thermostatic water valve that the 40 HP does not have. The valve regulates coolant flow so the engine holds the right temperature across the load range, including at full load where the extra 20 HP is being made. The 40 was tuned to make less power, so it was fitted without that valve. Once you load the 60 HP calibration, the engine needs the 60 HP cooling to match, and that means adding the valve.

This is the one genuine hardware difference between a 40 and a 60, and it is the reason the 40 to 60 step is not simply a bigger version of the 40 to 50 step. It is also the reason we do not hand you a reflash and leave the cooling to chance.

How the valve is handled

We supply the correct thermostatic water valve for your engine as part of the upgrade. The valve is a defined part fitted in a defined place on the powerhead, and the owner installs it on the engine. To be clear, we supply the valve but we do not install it for you. It is a straightforward, self-contained job, and once it is on, the 60 HP cooling matches the 60 HP calibration. The valve is priced separately from the reflash.

What it costs and how it is done

The reflash itself is a fixed price, and the water valve is supplied on top of it:

All prices are ex VAT. With remote tuning the EMM never leaves the boat. You sit at the dock with a Windows laptop, a diagnostic cable, a bootstrap cable, an internet connection and a charged battery, and we reflash the module live, usually in under an hour. Prefer to post it? A mail-in EMM is typically back in the post within about three days of arriving. With mail-in you pay carriage both ways (sending the EMM to us and getting it back), whereas the remote option ships nothing because the EMM stays on the boat.

Either way it is plug and play. This is real rated power, the manufacturer's own 60 HP calibration, not an over-tune. Hardware Care is based in Nieuwkuijk, Netherlands, and works with boat owners worldwide by DHL Express. We have tuned over 100 EMMs to their higher factory rating.

Step your E-TEC 40 up to a full 60

Twenty more horsepower is already inside your block. All it needs is the 60 HP calibration and the matching water valve, and both are handled in one order. Read your EMM part number, then check the 40 to 60 HP upgrade to confirm eligibility, or compare it against the simpler 40 to 50 HP path and the full EMM tuning hub.