Throttle valve not opening fully

It's a good idea to check that your throttle valve opens fully when throttle is set WOT position.

I noticed that this was not the case with my Madeira 40 and I was not getting the full power!

Fortunately this is easy to fix, you need to remove the airbox first, then put throttle to wide-open position and check that throttle valves are fully open. If the throttle valves are not horizontal you need to loosen the bolts holding the part number 9005740 "Accelerator cam" and slide it downwards.

There should be no gap in neutral or WOT throttle positions, make sure to test both!

If there is a gap where the yellow arrow points then adjust
the accelator cam by loosening two bolts (indicated in red).
I had a gap in the idle position and thus the valves did not open fully.

Now the throttle valve is fully open in WOT position.

Converting Madeira 40 to Madeira 50 (Part 2)

It was time to test Madeira 40 on water with bigger Dellorto 38/34 carburetors.
I did not change the propeller so the test was done using Signature 11 1/4 X 18 semi-cleaver.

This summarizes the gains in top speed best:

I did not notice any increase in the top speed and the motor did not reach higher RPMs.
So bigger carburetors do not necessarily mean more power. The outboard was also stalling at trolling speed, I need to work with the fuel/air mixture screws.

The remaining difference compared to 50 HP model is the cylinder head, I'm planning to replace also that and see what happens.

Selva Madeira reed valve blades

I was considering to upgrade the stock Selva Madeira reed valve blades to carbon fiber ones but didn't have time look for suitable replacement blades. At least Boyesen makes reeds for outboards.

The stock blades are made of fiberglass so I'm not sure if one can see any noticeable difference in the performance after switching to carbon fiber blades. The fiberglass is good material as the engine will not suffer damage in case the blade breaks (same goes for the carbon fiber). In case someone wants to try different blades I have listed the specs below.

Selva Madeira 40/40XS/50 reed valve blades:

•  blades are not attached to each other, every blade has it's own screw.
•  the number of blades is 12 per reed valve so the total is 24 blades per outboard.
•  the length of the blade is ~52.5 mm / 0.55 inches
•  the height of the blade is ~14 mm / 2.07 inches

Selva Madeira reed valve with 12 blades.

The length of the blade is ~52,5 mm.

The width of the blade is ~14 mm.

The width of the blade is ~0.55 inches.

The length of the blade is a little over 2 inches.