Winky Blinky

[justpracticin]

Does anybody have one they would be willing to loan or rent?

[Steelin' Ducks]

I'm very hesitant to Google what that is...

[DRDUCK]

Yea what is it?

[Smilee]

Code reader for boat motor and good luck getting someone to loan one

[ecu1984]

OBD code reader for Yamaha.
Number of time the light blinks is the trouble/diagnostic code you look up on the code chart.
What model and year outboard? What's it doing?

[Sportin' Woodies]

Do they make a winky blinky for your forscan?

[DRDUCK]

Do they make a winky blinky for your forscan?

Naw Sportin', you thinkin about the flesh light. Keep up!~

[justpracticin]

OBD code reader for Yamaha.
Number of time the light blinks is the trouble/diagnostic code you look up on the code chart.
What model and year outboard? What's it doing?

'01 OX66 250 Yamaha.

Occasionally cuts off at higher rpm (above 2700) with no warning. Starts right back up. Fuel filter has just been changed and VST filter has been cleaned. Water temperature thermosensor is showing continuity at room temperature which should be normally open up to 174 degrees or so. Will verify battery connections tonight.

[Gone South]

Oxygen sensor is a common maintenance item for ox66. I would look into that but been a while since I’ve dealt with one, so I’m not saying that’s a confident solution

[justpracticin]

O2 Sensor cleaning is a common maintenance item, but that usually shows up with performance issues. Mine just cuts off; other than that, it runs great.

[ecu1984]

very familiar with it
I have owned several of them. The best two-stroke outboards ever made.
O2 Sensor and TPS setting are the usual suspects. I think I have the test harness for each out in my garage.
Clean fuel, clean fuel, clean fuel and fuel pressure are a must. I think a fuel pressure gauge should read 38psi at all times leaving the VST
and headed toward the injectors, if I remember correctly.
Many people overlook the little "mystery filter" coming into the top of the VST tank (little screen inside fuel pressure regulator). This little $5 screen has
caused grief for many Yamaha mechanics and found to be the issue after $1000s in part throwing.
Also, your low pressure fuel pumps are cheap and easy to replace. If throwing parts at it, start with plugs and ALL fuel filters.
Very reliable oil injection system too. often when an OX66 does pop a cylinder, the first thing the mechanic blames is a "faulty oil pump"
when it usually is not. It is caused by a faulty fuel injector. Take them off and send them out to get cleaned, tested and rebuilt.
Need to determine if it's electrical or fuel related.
Questions:
1) is is running fine and just instantly shuts off or does it start running rough and then dies?
2) does it instantly start right back up and then run fine at all rpm ranges once started, like nothing is wrong?

[ecu1984]

Due to it happening at higher rpm, I am thinking the VST tank is running out of fuel
then, it dies and VST bowl fills back up and off you go again. Just one thought
or its electrical
Known issue - Unscrew the in-line fuel check valve, throw the guts away that are inside it and then put it back together and install

[DJP]

Some UofSC fans support the removal of the winky blinky and some want to keep it.

[ecu1984]

Stephen,
I wrote most of the below and pieced together some of it from others for a friend of mine in NC a few years ago.
Excuse the jumping around in it but there may be something in here you can use.

Yamaha OX 66 250HP Saltwater Series
Service Notes

Rough idling – stalls - poor acceleration trouble shooting
Testing
Normal OX66 troubleshooting goes, check spark, check compression, fix the fuel system.
With a diagnostic test lamp, a DVM with a DVA adapter, a fuel rail test gauge and some system knowledge and the tune up spec guide this motor is easy to check.
basically fuel supply to the VST, rail supply from the VST, then ignition producing components and ignition controlling components. only thing that can get iffy is checking the injector screens.

There is no good test for the knock sensor other than checking for a code with the “winky blinky” light at the problem RPM.

The O2 sensor test MUST be made with the boat running at its normal range and with a warmup period of about 10 minutes.

It’s not common, but always be aware that the injectors have screens, 6 of them, they are subject to clogging as well and give NO codes or indication other than they can run that cylinder lean.

Also know if any sensor on this motor fails ,except the O2 and the thermo-sensor, that the engine defaults to a fixed 7*BTDC and top speed cannot be reached (limp mode)

This engine runs with a CCS type ignition system. When the ECU sees the temp above 115 and idling, the motor drops two cylinders.
Specifically, you lose spark on #5 until you reach about 2000 rpm and spark is lost on #2 cylinder between 850 rpm and 2000 rpm.
People often complain about the OX66 rough idle, they don't know it idles on 4 cylinders by design

These are all key troubleshooting features; this motor will mostly test itself if you simply pay attention to what it is telling you.

First test compression, needs to be within 10 psi on all 6.
Next test spark, needs to be able to jump a 7/16th" gap on all six when cranking.
To test the plug caps unscrew them from the plug wire and test with an ohm meter per the service manual.
Once we know the ignition system is ok and the engine is mechanically sound it’s on to the fuel system, test fuel rail pressure, needs to be 35 psi at any engine speed.
So far there is no good test for the injector screens, if injectors are suspect then an injector service will be in order.
When describing a lack of fuel in the cylinder; and if you must inject a fuel in the throttle body use a squirt can with a 50/1 premix of gasoline/2 stroke oil.

Use the diagnostic test lamp (winky blinky) and check for codes or use the service manual and you can test each sensor with a multi-meter.

TPS voltage is very important as is the correct crank position sensor output voltage.
The diagnostic test lamp will only display a code IF the code is currently active.
A loose knock sensor will toss a code and retard timing as well as clogged O2 sensor draw tubes that are knocking in the block.
Once running, the fuel rail MUST maintain 35 PSI + or - 2 psi or it can’t run correctly.
On the rail, too much fuel pressure and it gets very rich very fast, too little and it gets lean very fast.
the O2 sensor can fail/be contaminated and lean it out above 4000 RPM as well.

A quick test of the fuel pressure regulator that’s not in any manual.
Use needle nose pliers and close off the rail return line when pressure drops, you can then "regulate" the rail pressure with the needle nose.
Debris can cause the regulator to allow too much leakage yet statically test ok.

Winky Blinky Test Light
To attach the winky blinky to an OX 66 you unclip the wires from the engine oil tank, plug the big lead from the winky to the engine side of the harness, then look on the engine side for a female blue wire. it originally had a black rubber plug to seal it. plug the bullet connector male from the winky blinky into that female blue wire.
with key on power it will work but most codes will need engine cranking or running to retrieve.
be aware that for extended testing there is NO automatic oil transfer from the remote tank to engine tank with the winky blinky installed however manual transfer will work.
Codes will be displayed lowest to highest but only 1 code at a time, the first code must be repaired before any others can be displayed.
Should see about 1100 rpms with a code 33 then dropping to normal idle with code 1.
code 1 means everything the ECU monitors is normal.
Code 33 means the ECU is in engine warm up mode with fixed timing and fuel corrections based on inputs from the thermo-sensor.

The fuel system.
We will break it into 3 sub parts.
The first is the tank and lines up to the three low pressure fuel pumps,
nothing here will allow fuel into the block.
Now we are going to look at the three low pressure fuel pumps mounted on side of block.
3 lift pumps and they are prone to failed diaphragm which will allow fuel into the crankcase if any one of the 3 diaphragms are ruptured but once the engine is off they quit moving fuel.
they also make it idle funny at low speeds and you will see a lot of fuel rainbows on the water at idle.
A faulty low pressure pump can blow a motor because the ruptured diaphragm lets gas into the crankcase and washes out a bearing or connecting rod. They are cheap and easy to replace.

The VST tank
The high pressure pump picks up fuel from the vapor separator , its simply a tank.
from the high pressure pump it is fed to the fuel rail, what the injectors can’t feed the engine is fed back to the VST through a vacuum operated pressure regulator that will maintain 35PSI on the rail regardless of how rapid the throttles are opened, remember if the TPS signals the ECU the throttles were opened rapidly that system will go to synchronous and assynchrounus injection at the same time.
the fact that as soon as you shut the motor off pressure falls leads to a bad regulator diaphragm or a sticking injector.
if the needle valve in the VST sticks it will run very rich but rail pressure won’t be affected at shut down.
a quick test for the lift pumps is with the engine off simply pump the primer. if a diaphragm is leaking the primer will never get hard and you will hear the fuel moving, same if the VST float needle is leaking. the VST is vented to the intake and if the float needle leaks it will overflow raw gas into the intake at number 5cylinder, I think its #5 . memory there is fuzzy.
trace the vacuum line from the pressure regulator to the intake, unplug it, turn the key on and see if gas squirts out. if it does the diaphragm is bad, if it does not continue testing but don’t rule it out.
You will find the 3.1 motors are rather hard on low pressure pumps and very thirsty above 4200 RPM. any debris in the VST will shut it down and any defects in any of the lift pumps will do the same.
First symptom of a bad low pressure pump diaphragm is poor idle and fuel sheen on the water while idling at the dock, second is it runs out of fuel at the top end.
It’s a race to see if a rod exits the block BEFORE the piston skirts fail.
Usually once the primer is pumped up hard, then keep light pressure on it and see if it goes flat again, if it does you have a leaking pump diaphragm filter or VST needle issue.
Just because the fuel pump whines for 3 seconds at key on power DOES NOT MEAN the high pressure fuel rail is at the correct pressure just means the pump armature is rotating.
HP fuel pump - you just need a fuel rail test gauge and a digital voltmeter.
slip the meter pins up the red and blue wires on the pump.
attach the pressure tester.
start the engine.
fuel pressure should be about 35 psi and voltage about 9v.
take off and run, pressure should stay about 35PSI at all RPM's and voltage above about 1200 will increase to about 11V or better.
now when it falls on its face observe both readings.
should still have 35PSI and above 11V.
if less than 11V check all grounds and hots between everything.
if 11V or above and less than 35 PSI check all fuel system components for restrictions, proper lift pump outlet pressures and the VST screen for debris.
if all check out then send your injectors out for service.
The OX66 motors can sense low battery voltage(big current draw with the trim) and increase the injector on time allowing more fuel.
the ignition system is basically independent of battery voltage.
Have you removed the injectors, then removed the injector filters, then reinstall them?
each injector has a filter, use a knife and carefully remove and clean or replace them.
Yamaha doesn’t offer them but they can be found by a Mercruiser dealer looking for about a 2001 7.4 MPI.

O2 Sensor
A rattling sound is most likely the O2 sensor draw tube, remove it and clean it.
if you notice one or both ends shiny you will know it was the draw tube.
a clogged or dirty tube will sound exactly like a wrist pin rattle at idle.
Cleaning: Make sure the cleaning solution does not get over top of the crimp on the sensor.
Clean the draw tube.
The O2 sensor bench test is a waste of time and meaningless.
On the OX66 motors if the O2 sensor tells the ECU its rich the ECU can and will lean the mix above 4000 RPM to a point that detonates pistons from a lean burn. A bad or incorrect O2 senor signal can wipe a piston. Yes, they cost close to 300 dollars and yes, they go bad occasionally. the test harness is about 20 bucks and the VOM at radio shack is about 25 and the test procedure is in the 03 and 04 tech guides.

Spend the time testing for proper O2 sensor voltage outputs first.

Connect O2 Test Harness: On the O2 sensor, test the heater voltage at the blue connector for battery voltage with the key on.
Test the green connector with the gray wires for a varying voltage between about .35v and about .6v after a 15 min run above 3000 RPM. Voltage should vary rapidly between .3 and .6 at 3000 RPM.
.1 indicates very lean, .9 indicates very rich and the ECU will alter fuel delivery regardless of if it’s a correct signal or not.
The lower unit MUST be submerged when testing sensor output voltage.
The output voltage should be .35 plus or minus about .1 volts and vary. To test the reaction, remove the airbox. install the test harness, plug in your DVM and start the motor with the gearcase submerged. allow 5 to 10 min to warm up. now close off the upper air bypass hole in the top throttle plate. the meter should swing towards .9v. when you remove your finger it should head back for about .2-.3V. then it should start scaling between .3 and .6 V at idle. if it does not it’s not working correctly and above 4000 RPM if it tells the ECU the fuel air ratio is rich the ECU will keep leaning the mix until a piston scuffs.

if you disconnect it, the ECU will fix fuel rich at idle and lean above 4000, do not run above 4000.
if this engine is anything but a VX225 it incorporates CCS which
means below about 500 RPM all six cylinders spark, from about 550 to about 2000 #5 does not spark, from about 850 to 2000 #2 does not spark.
VX motors DO NOT incorporate this feature.
when I say the ECU on that motor wont store a code it means this;
if the code is active it will register, however if the code is inactive it won’t leave a record that it was ever set.
So if at idle my winky is showing code 1 doesn’t mean at 4800 I won’t be blinking a code other than
This system only shows a code if the code is currently active, if it’s not, you get code 1.

Fuel rail pressure MUST maintain at 35 PSI at ALL rpm ranges or something is broke or clogged.
Always remember how the PBS transfer system works for the particular engine your working with. The OX66 system does NOT inject oil into the crankcase like all other Yamaha systems, it adds all oil to the VST via a manifold. the check valve simply keeps oil from draining back OR keeps gravity from forcing oil into the VST when sitting.
The only way we can get oil into the airbox on that engine is via the vent line, several causes of oil tank overflow - the most common is an incorrectly installed engine tank screen.
Now a certain amount of fuel/oil spit back is normal and then the fuel will evaporate and leave the oil.
The gray hose on the lower port side of the airbox to the intake should remove this for combustion.
if the hose is disconnected, clogged or missing you will see it drip.
on a 250 OX66 any sensor other than the thermo-sensor and O2 sensor, if they fail out of range OR are disconnected timing will be fixed idle speed increases usually to about 1100 and top speed cannot be reached, however a loose knock sensor can drive you nuts.


Misc Sensors
A failed sensor will lock idle timing at 7* BTDC, idle speed will increase, and top speed cannot be reached.
At 68*F thermo-sensor resistance should be about 61K Ohms and at 212*F about 3K ohms.
A quick test is to unplug the sensor, hook the meter leads on the sensor terminals, start the engine, as the engine warms up the resistance should start dropping. should go from around 61K to about 4 K or so, if it does not either the sensor is bad or the T stats are bad. if the resistance changes start tracing wires back to the ECU for breakage.
if the electric pump becomes unplugged the timing should get fixed to 7* BTDC and engine speed should increase to about 1100.
remember there are 2 temp switches and 1 temp sensor.
The knock sensor is a single wire sensor located on the starboard head down low, unplug it and timing is fixed again.
TPS- Code 18 means the ECU sees the TPS feed-back out of range.
test the TPS 5V reference, orange to black
Any orange wire under the hood is 5V reference and any sensor can take it down.
Winky only shows 1 code at a time and then only the lowest code number first.
There are NO issues with the CDI that can cause an oil failure.
alarm issues, yes.
The CDI does NOT control the engine oil pump just the transfer pump.
However IF the alarm system works, and its simple to test, you have about 20 minutes of oil in the engine tank when the alarm triggers.
IF the alarm works and the key switch kill circuit is grounded it sounds when you crank the engine.
don't need to start the motor to test any sensor on that engine.
all can be tested while static. you can also use the diagnostic test lamp.

Misc Issues
Rough idle and excessive smoking at idle – oil linkage rod adjustment and the oil pump shaft seals can leak and allow crankcase pulses to pull oil directly into the lower cylinders, the seal and o-ring are easy to replace. Also possible an oil line check valve(s) is bad, easy to test with a vacuum pump.
Unscrew the inline fuel check valve, dump the guts out and reinstall it.
today’s fuel blends can and do cause the valve o-ring to swell and stick the shuttle.
Test the O2 sensor voltage output as well as testing rail pressure at the problem RPM.
Doesn’t matter if the O2 sensor is clean or dirty, it’s about the voltage feedback to the ECU. On the O2 sensor your looking for a scaling voltage between about .3 and .6V.
The OX66 motors also use the pulser coil signals to trigger the injectors.
the injectors inject the fuel AND the lubricating oil.
On the Ox66 the pulser coils not only control the CDI output it also controls fuel injector firing time.
Lose a pulser input and code 13 is displayed and that ignition coil doesn’t fire and the injector it controls doesn’t provide fuel.
takes 5 minutes to test the CDI output on all 6 cylinders.

[justpracticin]

Wow Rick! That is an awesome reference. I have tightened all grounds and am fixing to run it. I appreciate the maintenance tips. I will get back on it tomorrow night.

[justpracticin]

Wow Rick! That is an awesome reference. I have tightened all grounds and am fixing to run it. I appreciate the maintenance tips. I will get back on it tomorrow night.

[ecu1984]

There are plenty of "certified" Yamaha techs around, but there aren't many "MASTER" Yamaha tech's in SC.
Night and day difference in "certified" vs "master certified"
There was a Master Yamaha tech between Irmo and Chapin.
I have his name and number somewhere if it comes down to it

[billbuster84]

There’s a guy in Rock Hill that is a master Yamaha guy, but he has a hell of a waiting list. At least he did the last time I called him.


Sent from my iPhone using Tapatalk

[justpracticin]

Thank you Rick,

Ran it last night for 45 minutes, not a hiccup at all. The initial problem surfaced after I had changed the fuel filter. Your suggestion about the VST tank "running dry" seems to have been spot on. I suspect I had not primed it properly. Probably going to run it again tonight.

[ecu1984]

Your high pressure fuel pump is inside the VST tank.
It has a filter on the end of it also
There is a float w/ needle and seat inside the VST also (just like an old school carb)
It that float height isn't set correctly, you will run out of fuel at higher rpms also.
Hope you got it straightened out
Keep us posted