Today my Selva Madeira was not starting although the battery was fully charged, basically nothing happened when I turned the key, the only thing I heard was a small whining noise coming from the motor.
I checked that the safety leash was connected, the gear was in neutral position and the motor start cables were properly attached to the battery.
First I thought that there is some kind of electrical failure so I opened the engine cover,
I tried to rotate the flywheel and noticed that it was stuck. It was quite hard to notice but the starter motor drive gear was barely touching the flywheel gear but enough to block the rotation.
I tried to rotate the flywheel using an emergency pull rope but it was too stuck.
Then I sprayed a little WD-40 on the top of the starter motor and gave two knocks with a wrench,
the starter motor drive gear dropped a little and the the flywheel turned and was freed.
After that the motor started without any problems :)
Tap here gently if your flywheel seems to be stuck.
How much does one inch propeller pitch change affect motor revolutions per minute ?
If you do some googling some say that increasing propeller pitch by one inch decreases motor rpm 200-400, some say that increasing propeller pitch by two inches has 300-400 rpm effect. Boat U.S. states that the effect is 200 rpm if the propeller is cupped and the diameter stays the same. Stuart Allen from Dangar Marine also seems to acknowledge this 200 rpm per inch rule.
I wanted to test this in practice, of course every boat and motor combination is unique and the results will vary. I'm talking about Solas Amita 3 11x16 versus Solas Amita 3 11x17. Some say that Solas Amita 3 is a cupped propeller and in this case the only difference should be the pitch size as the diameter is the same (11").
So here are the results:
With Solas Amita 3 11x16 my Selva Madeira 40 XS reached about 5 650 rpm with wide-open throttle. That is above the recommended maximum 5 500 rpm. The motor was trimmed as up as possible.
With Solas Amita 3 11x17 the motor reached about 5 300 rpm. The top speed was two knots lower with this propeller.
Solas Amita 3 labels.
So one inch increase in the propeller pitch resulted to 350 rpm decrease.
I was a little surprised of this result, I was expecting a drop of 200-250 rpm.
It's quite annoying that with higher pitch propeller you don't reach the recommended rpm range and with lower pitch you go over the limit.
This is just speculation but could it be that aluminium is not a good enough material to produce higher pitched propellers in 11" propeller size class. Why does Solas stop the range at 17" pitch ?
It's quite hard to find original Yamaha propellers which have more than 14" pitch.
I'm planning do more testing after I have changed the engine mounting height, currently Selva is mounted to the lowest possible hole and it's producing an excessive rooster tail.
I would like to also test a stainless steel propeller with 16-18" pitch (semi-cleaver type).
My Selva 40 XS is a quite thirsty outboard, I noticed that a portable 30 liters fuel tank is not enough when doing longer cruises. Italian based Nuova Rade manufactures inexpensive plastic-like fuel tanks named Diablo.
I bought a 48 L Diablo series tank, actually the tank is a multi-purpose tank suitable also for water or waste and the hatch is packaged separately. The hatch is different for each purpose and for the fuel tank you get these parts:
The tank itself is white and looks like this:
I didn't get any installation instructions with the tank or the hatch so I downloaded those from the Nuova Rade's web site. I was a little surprised that the instructions were quite limited and didn't provide much details about what parts goes where.
I want to fill this tank in the same way as you fill a portable tank (just open the fuel cap and feed fuel directly to the tank). For my intended use I noticed two problems with the hatch, the first problem is that there are six holes and you get only four normal caps, one hollow cap is used to connect the fuel hose, this leaves one open hole.
The second problem is that the cap that covers the biggest hole (fuel input) is quite hard to turn and it does not have any "breathing" functionality.
For 48L tank you need to cut the black pipe in half in order make outbound fuel delivery line, fortunately there is already a mark where to cut it. The other black pipe is extra (maybe meant for diesel engines in order to pump diesel back to tank ?).
One mid-sized hollow cap was extra so I decided to use it to cover the sixth hole,
I noticed that you can put a quarter dollar there and with one O-ring it makes a perfect seal! ;)
A quarter dollar coin was used to seal extra hole.
In order to make the tank "breath" I drilled a couple of small holes to one of the smallest caps, this seemed to to work but on the water I noticed that some fuel was spilling out when the boat swang/jumped in the waves. The largest cap has 1½" threads and after lots of searching I found a perfect replacement cap from Plastimo, it also has an air screw!
Now the setup was complete and it has been working very well, I even installed a fuel sensor and a Wema fuel gauge. I never installed the red locking pin.
Plastimo cap allowed the tank to get replacement air.
According to Selva Marine you should use Champion L78 or Bosch W3AC spark plugs with Selva Madeira 40 XS. The 50 HP model uses the same plugs. Some matching spark plugs from other manufacturers are:
NGK B8HS
DENSO W24FS-U
MOTORCRAFT AE901RAC
I found a web site named MAGNUM Tuning which markets performance spark plugs and they have even listed Madeira 40/50 outboards!
I ordered two spark plugs and got these guys:
Racing spark plug for Selva Madeira 40 XS.
These "racing" spark plugs are manufactured by Brisk and the exact type is NOR14LGS.
MAGNUM Tuning states these benefits:
- Delivers 3% gain in horsepower and torque
- Notably improves throttle response
- Improves acceleration throughout the RPM range
- You can realize +5% fuel efficiency improvement
- Increases firing energy by up to 15% Flat spots cease
Brisk states this on their website:
"Our BRISK Premium LGS spark plug utilizes a very unique, semi-surface discharge electrode design. By implementing this design, the spark plug is able to fire a much larger spark plug gap, because the spark glides along the surface of the insulator, requiring much less energy than firing a traditional style air gap. Longer spark discharge makes more contact with the A/F mixture, igniting more molecules in the A/F mixture over a larger area."
My converted Selva 40 XS should produce 50 HP so with these spark plugs I could obtain something like 51.5 HP. Is that enough to make some difference ?
I installed the Brisk spark plugs and did a short test run. The engine started quite nicely, maybe a little eager than before. Unfortunately the engine stalled when I switched from neutral to forward.
This happened three times so I opened the engine cover and raised the idle speed, this helped a little but when I came back to harbour the same thing happened again (when switching from neutral to forward), my engine idle speed is quite high 1200-1300 rpms so this should not happen!
Brisk NOR14LGS spark plug being installed.
I cannot simply blame the spark plugs since the engine is running quite rough even with the stock spark plugs, maybe there is some problem with the air/fuel mixture or carburetor idle jets are dirty.
However with the stock spark plugs the engine has never stalled.
Anyway, I did some cruising with wide open throttle and didn't notice any speed gain, the sea was a little rough and thus the conditions were not perfect for accurate results.
I'm planning to do one more test in better weather conditions.
After studying the parts listing I noticed that Selva Madeira 40 XS is identical to Selva Madeira 50. The only difference is the part number 73 labeled as an exhaust separator. Once again visiting Gommonauti.it forums I was convinced that removing that plate should give more horsepower for my Madeira 40 XS. It seems that the only purpose of that plate is to restrict the flow of exhaust gases.
I proceeded by removing the lower unit as described in the previous post. For my surprise there wasn't any plate, I guess the previous owner has removed the plate already. My engine was manufactured in 2005 and it should come with the plate. I cannot say for sure but it looks like you can remove the plate without disconnecting the shift rod, this makes conversion quite easy. You may need to adjust the mix and idle screws after the conversion.
Exhaust downwards
Exhaust upwards
So how much more power can you get from this conversion ?
I cannot provide any real data since my motor was already altered, I can only speculate. Selva manual states that on average Selva Madeira 40 consumes 14 l/h WOT and 50 HP model 16 l/h. The provided average consumption for Selva Madeira 40 XS is 15 liters per hour, could this mean that out of stock 40 XS has actually closer to 45 HP and you would get only 5 HP more from this conversion. I also would like to know what does XS mean, is it Extra Strong or something else ?
Anyway, remember that if the motor revs above 5500 rpm after the conversion you need to consider higher pitched propeller, at least Solas Amita 3 (Yamaha) propellers are available in 11-17" pitch range.
In order to check or replace the water impeller one needs to remove the lower unit of the outboard. It was very difficult to find instructions how to do this. I found a message thread on Gommonauti.it which described how to remove the lower unit of Selva Naxos 15. Fortunately Selva uses similar construction on bigger engines also. The method I describe here most probably applies also to Madeira 40 and 50 and maybe also to St. Tropez.
First I removed the propeller and the engine cover and placed a load strap loosely to support lower unit from falling down. I don't think this is necessary but load strap is useful when you are putting lower unit back. Then I drained the gear oil by opening three screws, I'm not sure if this
is needed but I needed to change the gear oil anyway. Then I opened one nut and three bolts and turned gear to reverse. After a couple hits with rubber hammer the lower unit dropped two centimeters. Now a bolt connecting upper and lower shift rod is visible and can be opened, after that the lower unit can be removed.
Unfortunately I have not found the service manual anywhere, I have requested that from Selva Marine and regional distributors but no success so far. Maybe some day...
My Selva Madeira 40 XS is running a little rough and I wanted to adjust idle speed and low speed air/fuel mixture. Unfortunately the user manual does not even mention these topics and I have not been able to acquire the service manual.
With a little help from Italian guys from Gommonauti.it I collected courage to adjust screws next to the carburetors.
One needs to adjust screws 2 and/or 3 to adjust idle speed. Of course your motor needs to be warm before messing with these screws. I adjusted the idle speed to 1000-1200 rpms. You need turn both screws same amount. Update Sep 2018: you need to turn only one screw, it will adjust both carburetors the same amount as they are synchronized.
In order to adjust low speed fuel/air mixture you need to adjust screws 4 and 5.
The range is 2-2 1/2 rounds. I first closed both screws and noticed that they are not perfectly aligned so you need to be careful when rotation those. I used marker pen to color half of the screw, it helps a little when you are turning the screw.
You should first adjust fuel/air mixture and after that bring the idle speed to suitable level using idle speed screws. I don't know what is the proper idle speed range for this motor but about 1000 rpms is the most common value.
Dangar Marine has published a great video about carburetor tuning, I recommend to watch that before touching anything =)
I need to find more suitable propeller for my Selva Madeira 40 XS as it's revving 5900 rpm with stock propeller. Stock propeller has 3 blades and size is 11.6" x 13".
I first though that propeller is Evinrude/Johnson compatible but it's not.
For some reason you can install Propulse 6901 propeller without problems. http://propulse.se/butik/propellrar/propeller-6901/
Don't waste your time with Solas Amita 3 for OMC, it does not fit at least
with stock thrust washer, I was not able to put the split pin, propeller height is the problem.
Selva stock propeller
I was told that my outboard it Yamaha compatible so I bought Solas Amita 11x16" for Yamaha (SOL3311-110-16).
I was able to install this propeller but I needed to remove metal ring on top of thrust washer and place that after propeller. Then came washer and propeller nut. I used only original parts that came with the outboard.
I have purchased old Selva Madeira 40 XS outboard.
Since it's not the most common outboard out there it's quite hard to find proper information especially if you are not fluent in Italian. The idea of this blog is to share information about maintenance and various technical topics.
