Milky gear oil and pressure testing the gearbox

I was changing the gear oil for my Selva Madeira outboard and noticed that the color of old oil was somewhat milky which indicates some presence of water. The color of the oil was not white but gray.

Milky gear oil.

I have noticed that the outer oil seal on the propeller shaft does not look particularly healthy, the lip of seal is pushed outwards, maybe the water is going in there ? I have changed the oil already once during the summer, I did not use new O-rings in the plugs, I know that is not a good practice.

The outer oil seal does not look healthy.

I wanted to do a pressure test for the gearbox, Dangar Marine has posted a nice video how to do it. I used very inexpensive parts to assemble a simple pressure test rig.

Parts list:

- gear oil pump (Biltema)

- fuel system pressure gauge (Biltema)

- one T-connector 

- bike hand pump

- hose clamps

I did a check for the test rig by raising the pressure to 10 PSI and put the connectors under water to see if there were any leaks, everything looked good and the rig was able hold constant pressure for several minutes.

A simple gearbox pressure test rig.

Selva Madeira has three oil drain holes, the yellow connector fits only to one of them.

I don't have Selva service manual so I decided to do similar test that was done in Dangar Marine video for Yamaha 50 gearbox. I increased the pressure to 10 PSI and there was not drop in the pressure after 30 seconds, not even after 60 seconds so I think that the seals are working quite well (at least when the motor is not running).

The only oil drain hole which accepts the yellow connector.

The gearbox was able to hold 10 PSI over 60 seconds.

I'm not sure why there was water mixed in the gear oil if the pressure test gives good results.

I plan to replace at least the oil plug O-rings and consider replacing the lower unit oil seals which is a harder task.

Solas Amita 3 losing paint

The winter is coming so it was time to take my boat from the water.
After inspecting the motor I noticed that the Solas Amita 3 (11"x17") aluminium propeller has lost some paint from two blades. The areas were in the same section of the blade and of similar size.
The low pressure side of the propeller looked good as new.
I'm wondering what has caused this, last season I used Solas Amita 3 11"x16" and it survived the whole season without any paint issues.

I have raised the engine three holes so the propeller operates closer to the water surface, sometimes the motor sucks air and hits higher RPMs and then suddenly the grip returns.
So I guess the ventilation can be the root cause, I suppose cavitation should cause problems on the other side of the propeller or at least closer to the tip of the blade.

Paint (or coating) is missing from two
blades on the high pressure side.

Everything looks good on the low pressure side.

Selva Madeira power trim problem

I was at sea and suddenly noticed that Selva Madeira 40 power trim was going up but not down.
I tried also the tilt switch on the motor but it didn't work either. I was able to get to the harbor slowly but surely.

When I pressed the down switch there was a clicking noise coming from the relay but the trim motor was not spinning at all. I did some study on Youtube, once again thanks to Dangar Marine, there is a nice video about outboard trim-tilt relays.

You can see Selva Madeira trim-tilt relays in this diagram (number 55). The Selva part number is 8515070 and the relay is manufactured by Hella and the product code is  4RD 931 680-01.

I opened the engine cover and checked the relays visually, nothing special spotted my attention.
The plan was to take relays off and switch them in order to see if one of them was faulty.
I used a small flat screwdriver to detach the relays and put them back in different positions.
For my surprise the trim started to work fully, I was able to trim it up and down.
I removed the relays again and tried to clean the connectors but they were in quite good condition. I sprayed some WD-40 to the relay base also.

Hard to say what was the root problem, maybe some conductivity problem.
This was a cheap fix! 😁

Selva trim-tilt relay part #8515070 (5-way relay 40A)

Trim-tilt relays connectors

Relay base

Testing over the hub cleaver on Selva Madeira 40

Today I made a test drive with Signature 10.5"x 18" over the hub cleaver propeller.
This was the first cleaver I have tested and compared to Signature semi-cleaver the difference was quite dramatic. On the first try I was not able to get the boat to plane, the outboard was screaming 6300 rpms which is 800 rpm over the maximum and still the boat was doing only 8 knots or so.

I was able to get the boat to plane when I moved myself to the center of the boat and the outboard was at WOT. With all other previously tested propellers the boat typically starts to plane extremely fast.

I guess the over the hub design, smaller diameter and Selva's quite large gear case is not the ideal combination but still I'm having hard time to understand why the hole shot is so bad.

Once the boat was planing the overall feel was quite good but still I noticed that the outboard was revving much higher than compared to Solas 11 x 17 round ear propeller.
I know that cleavers should be run very high, I don't have a jack plate and the outboard is mounted to uppermost position. However I was able to hit 6000 rpm without much effort so I think the problem not fixed by raising the engine even more. I think the propeller could have more pitch, maybe 20".

The top speed was a couple of knots slower compared to Solas 11" x 17" but I didn't want to push Selva over 6000 rpms.

Installing Hill Marine Signature over-hub cleaver propeller

I'm continuing the never ending quest for finding the optimal propeller for my Selva Madeira 40 outboard. I'm mainly interested to get the maximum top speed.

I have been reading lots of propeller theory and finally wanted to install a real cleaver propeller and see how it behaves.

I ordered 10 1/2" x 18" Signature cleaver for Yamaha 40-60 hp from eBay, this propeller has over-hub exhaust which means that exhaust gases go to propellers blades instead of going through the hub. In theory this kind of design should provide less drag and help with the top speed. On the other hand the hole-shot can suffer, I was willing to take that risk.

Signature 10 1/2" x 18" cleaver

Installation was very easy as I have previously installed Signature semi-cleaver propeller, I used the same XHS hub kit with slightly modified Yamaha thrust washer.

The weather was very windy so I didn't want to go for a real test drive, I only made a small test in the harbor. If I compare this propeller to Signature semi-cleaver 11 1/4 x 18 the difference is huge based on my limited tests at trolling speed. The semi-cleaver behaves more like normal round ear propeller whereas the cleaver seems to have very poor hole-shot, I raised the motor RPMs over 2500 and the boat was going only 5 knots. I think this mainly due to over hub exhaust, I'm a little afraid will the boat even plane 😅

Tiny-Tach tachometer blackout and reset

I was at sea enjoying great weather with my Selva Madeira when I noticed that Tiny-Tach tachometer stopped operating, there was nothing on the screen and pressing the button did not help.

I have been using Tiny-Tach to monitor Selva Madeira RPMs, I have been very satisfied with it,
I bought some cheap tachometers from China but was not able to even install those due to too short wires. The only thing I was a little skeptical with Tiny-Tach is that it has an internal battery which cannot be charged or replaced. I have read that the battery should last several years and my Tiny-Tach was less than a year old. Outside the season I have kept Tiny-Tach indoors to avoid freezing temperatures.

I contacted Tiny-Tach UK because that's where I got the Tiny-Tach with an extended sensor cable. The customer service from Tiny-Tach UK has always been great and now I got instructions how to reset the Tiny-Tach:

First lift a corner of the front sticker and peel it back.

To the right of the select button there is soft 'potting'.

Using a straightened metal paperclip or something similar probe the soft potting.

The object is to short the battery and reset the display. It may take a few attempts to reset.

It should go through a set up display and revert to zeros.

I followed these instructions and after a couple of reset attempts the device started to show zero hours. They even mailed me a new sticker to put on the display! 👌

The root cause of the problem remains still a mystery, it was extremely warm day so maybe the device overheated, this is just my speculation. The Tiny-Tach representative said this can be caused by too much red sensor wire or if the white wire has a poor or non-existent ground to engine block.

Resetting TinyTac using pincers.

Ready to install new cover sticker.

Good as new!

Selva 50HP Madeira 684cc MAGNUM Boat Performance Spark Plugs revisited

I wanted to test again Brisk racing spark plugs (NOR14LGS) now that I have upgraded to larger carburetors and lifted the Selva Madeira outboard to the highest mounting position.

I'm comparing against Champion L78 which is one of the recommended spark plug types by Selva owner's manual.

I'm only interested in the top speed gain and after careful testing there was a 0.4 knots difference favoring Brisk spark plugs. This difference is so small that it might be caused by weather, how high the outboard was trimmed and the differences in GPS accuracy.
I also found that my Selva Madeira was not trolling well, the engine stalled many times maybe due to too low RPMs. I raised the idle RPMs to 1200 but when the gear was on the RPMs dropped sometimes below 800 and Brisk spark plugs were not able to keep the engine running. With Champion spark plugs this did not happen.

To sum it up I'm not planning to use these Brisk racing spark plugs because I want the outboard idle and troll properly. Champion spark plugs are also very inexpensive.

Larger idle jets for Dellorto 38/34 carburetors

Recently I installed larger carburetors to my Madeira 40 outboard to match the ones in 40 XS / 50 HP models. Although the carburetors came from Selva factory the idle jets did not match the to specification. What I got was #65 although Selva documentation says that 40 XS / 50 HP models use #70 idle jets.

My Selva Madeira was not idling very well with #65 idle jets although I have adjusted the idle fuel/air mixture screws.

It's not particularly easy to find Dellorto OVC parts online, I noticed that EUROCARB is one of the few who is selling those. Unfortunately they had only one #70 idle jet available and told that they are not getting more. I ordered the one they had and then the problem was to find another one.

When I got #70 idle jet I noticed that it was exactly the same as #65 idle jet, the only difference was the size of the opening in the tip of the jet. I discovered also that number 70 meant 0.7 mm opening.

I decided to convert the #65 idle jet to #70 by drilling the idle jet using 0.7 mm drill bit.
I was not using a drill, only rotated the drill bit slowly until the opening matched the #70 idle jet.
I was extra careful not to leave any metal parts inside and used compressed air to clean the idle jet.

Once I installed these #70 jets to my Selva Madeira 40 it started to run more smoothly, at least I felt so.

From top to bottom:
#65 idle jet
#70 idle jet
#65 idle jet converted to #70 using 0.7 mm drill bit

Installing Michigan Match propeller

I was looking for an aluminium propeller with more than 17" pitch but those are quite hard to find. The propeller must be Selva Madeira compatible which basically means it must be Yamaha compatible. I found a Michigan Match 10.9" x 17.6" propeller for Nissan/Tohatsu and decided to order one.

This seems to be some older model which is not in the latest catalog, the product number is 142009.

Michigan Match 10.9 x 17.6

I quickly noticed that this propeller is not compatible with Selva Madeira stock thrust washer.
I decided to use the Yamaha thrust washer that comes with Michigan Wheels XHS hub kit 117, the one I modified a little.

There was still a problem with the compatibility, the diameter of the thrust washer was about 44 mm or (1 3/4 inches) leaving a 2 mm gap. I really hope someone could standardize the propeller fittings, it's very hard to install propellers from other brands. Of course Michigan XHS and Solas Rubex hub kits are trying to overcome these problems.

What I did is that I took magnetic tape and folded it two times to make a suitable adapter ribbon that was 1 mm thick. I used a bench vice to make it more solid, it was easy to install and after some lubrication the thrust washer installed quite nicely.

I think you can use any strong tape, maybe brass tape could be the optimum, I just had magnetic tape in stock 😏

Magnetic tape

Magnetic tape folded two times.

Custom adapter ribbon installed.

Yamaha thrust washer modded for Selva Madeira.

Michigan Match propeller 142009
ready to be installed on Selva Madeira.

Jun 7, 2018 update:

I tried to install the propeller but diameter of the outer body is too large and the propeller was touching the gear case and only barely rotating!
I'm planning to remove some coating and try again, will post an update later on.

Jun 30, 20180 update:

I used some sandpaper to make hub diameter smaller, now it's a little less than 80 mm and propeller spins freely when installed on Selva Madeira 40.

I did some tests on the water and propeller behaved quite well, still the top speed was a little slower than with Solas 11 x 17 so I'm keeping this Michigan Match propeller as a spare propeller.

14200

142009

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.

Converting Madeira 40 to Madeira 50 (Part 1)

When I did the carburetor cleaning some weeks ago I noticed that my outboard was Madeira 40 although it had Madeira 40 XS decals.

I have been playing with the idea how to convert this outboard to 50 HP and been studying the part listings.

This is what you need to change (I suppose):

• Both carburetors need to be replaced (going from Dellorto 34/30 to 38/34).
• The intake manifolds, those are the parts where reed valves are attached to.
• The engine head is different.
• Luckily there is no exhaust separator plate in Madeira 40 so no need to remove that!

I finally convinced myself that let's do the carburetors and intake manifolds and see what happens. The engine head of 50 HP model most probably gives more compression, I don't know how expensive that is but one can get similar results by shaving the engine head, I may want to try that later.

I was not able to find second hand carburetors so I decided to order new ones from Engine Marine Part. This conversion is not financially very well justified as the new carbs and intake manifolds costed around 800 € plus shipping 😂.

This is the upgrade plan:

1. Remove the air box
2. Remove Dellorto 34/30 carburetors.
3. Remove Madeira 40 intake manifolds.
4. Remove reed valves from Madeira 40 intake manifolds.
5. Remove tubes and plastic connectors from intake manifolds.
6. Attach reed valves to Madeira 50 intake manifolds.
7. Attach plastic connectors and tubes to Madeira 50 intake manifolds.
8. Attach Madeira 50 intake manifolds, connect oil tubes, and two air? tubes.
9. Move fuel connectors and linking arms from old carburetors to new ones.
10. Attach Dellorto 38/34 carburetors.
11. Connect fuel hose.
12. Make sure that carburetors are synced and closed at idle. Adjust idle and mixture.
13. Put the airbox back.
14. Start the engine!

Stock Selva Madeira 40 intake manifolds.

Madeira 40 intake manifolds removed.

Reed valves still attached to Madeira 40 intake manfifolds.

Reed valves and connectors moved from Madeira 40 intake
 manifolds (lower items) to to Madeira 50 intake manifolds (upper items).

Link arms, fuel connectors and all other stuff
moved to Dellorto OVC 38/34 carburetors.

The new intake manifolds attached.

The new carburetors attached, testing WOT throttle position.

The carburetor change operation completed.

First startup after the carburetor change, maybe it's a little bit more angry! 😎

Check also Part 2

Testing Hill Marine Semi Cleaver

Today it was time to test Hill Marine semi cleaver propeller on Selva Madeira 40. I switched from Solas Amita 3 11"x17" aluminium propeller. Many people say that you lose RPMs when switching from aluminum to stainless steel, some say that you gain RPMs. In my case I was going from 17" pitch to 18" so the RPMs should drop in any case. Semi cleaver is of course very different kind of propeller compared to round ear Solas.

I did the installation when the boat was in water, no major problems, I used two washers although the hub kit contained only one.

Hill Marine semi cleaver 11 1/4 x 18 on Madeira 40.

The stock nut and pin worked well.

This semi cleaver is a lot heavier than Solas aluminium propeller but I didn't notice any problems when switching from neutral to forward. The weather was quite windy and it was not able to get optimal results. I noticed that the RPMs at WOT where around 5400 rpms whereas with Solas they were above 5600 rpms, also the top speed was more than 3 knots lower.
I was able to trim motor up without the propeller losing grip, it seems that semi cleaver (as well as cleavers) likes run close to the surface of water.

I was not happy with the performance, maybe the propeller has too much pitch, I'm considering raising the engine to the highest mounting holes. I need to test again in calmer conditions and will try to trim the motor as up as possible. It is said that cleavers create transom lift but I did not notice anything worth mentioning.

Raising the engine two holes

My Selva Madeira 40 was installed as low as possible (the highest mounting holes).
I have noticed a long rooster tail and excessive spraying so I decided to raise the engine two mounting holes, that is the second highest position available.

Before

After

After raising the engine the RPMs increased from 5300 rpm to 5600 rpm using Solas 11x17" aluminium propeller and the speed increase was about three knots.
I think the engine can be raised even more as the propeller grips quite well and can be trimmed up without problems.

Here is a video taken after the the engine was raised.

Carburetor cleaning

Removing the carburetors

In order to remove the carburetors you must first remove the airbox.

Selva Madeira 40/40XS/50 airbox.

After that the carburetors can be removed by opening four bolts (two in each carburetor), the bolt holding electrochoke body and disconnecting fuel hose. Opening the carburetor bolts can be a little tricky as there is not that much space. Be careful not to lose the metal part called "electrochoke mounting plaque" when opening the bolt in electrochoke body.

Bolts that needs to be opened in order to remove carburetors.

Dellorto carburetors removed.

Intake manifolds and a peek of reed valves. 

Cleaning the carburetors

I was positively surprised how easy it was to disassemble Dellorto OVC 34/30 carburetors, clean those and put back together. First you need to detach carburetors from each other by disconnecting the rods syncing them and fuel hose. After that you can open the fuel bowl by opening four bolts.
Then you can unscrew the main jet / diffuser and the idle jet.

I noticed that in one the carburetors the idle jet was not positioned in the middle, I think it's a manufacturing fault as changing the idle jet did not correct the problem. I carefully bended the idle jet a little so that it was in the middle of the diffuser. My engine has been idling quite roughly so hopefully this might help a little.

You should check the jet sizes, correct main jet size for Madeira 40 is 160, for Madeira 40XS/50 it's 180. The idle jet size is 65 for Madeira 40 and 70 for Madeira 40XS/50. (Madeira 40XS/50 has larger 38/34 OVC carburetors).

Carburetors detached and float bowls removed.

The main jet, diffuser and idle jet.

Idle jet is not in the middle.

Idle jet position fixed by bending it a little.