Just a little insight into the oil side of the VRO2/OMS

[jbuote]

Wow... such great information here...
​Still relatively new to outboards, but I think I know more about VRO's now and I don't even HAVE one! LOL

Seriously though...
​Being new to outboards and boating in general, (And loving it all so far.. lol), I expect I may end up with an engine with VRO etc...
​
​I'm actually thinking this topic should become a sticky, or at least added in one of the "Sticky Lists" as a point of reference...
​Would love to have all this info if/when I end up with a VRO engine!!

​Love it cfauvel !! Keep it coming!

 

[cfauvel]

Great videos, best trilogy ive watched in a while.
What i was contemplating was if the outlet of the oil chamber where the reset piston is located is blocked then oil wouldnt get to the mixing fuel area and the alarm wouldnt sound as the oil pressure would still be high from the main piston still pressurising the oil chambers.

I don't think that if the lower half of the oil reset pin's piston is blocked that the alarm wouldn't sound, I think it WOULD sound as there would be nothing pushing up on the end of the pin.

I will say that the check valve for oil INTO the mixing area is super tiny....the oil has to be clean and free of debris.....I could see a piece of dirt keeping the check valve open...I would suspect that the reset pin would STILL work if that were the case, BUT you might not get a full draw of oil into the oil chamber as you'd be sucking from both the bottom flapper valve for the oil and from the top check valve which would be a fuel/oil mixture. The flapper valve is a much larger area to draw oil in.

And what i was wondering about the spring (bear with me) was that when the oil reset piston goes up and hits the counter reset lever then something must be pushing that lever back down so that it can then be hit by the reset piston when it comes back up again, if that thing that does that (which i assume is a spring) failed then it would seem the alarm wouldnt go on as the lever would drop on the electronic end and so be in a constant activated (resetting state). Since you say thats a sealed unit then i guess theres no way that the kits provide a replacement spring for whats under there)

And struth what a conincidence regarding your tach failing. That confirms the no tach no horn theory!

Ahh yes that is possible, highly improbable that something would clog the upper portion of the oil rest pin's piston (above the pin actually) preventing the pin to come back up to its normal position, thus in a state of constant reset.

From observations there are two things that prevent the pin in being in a constant state of reset.
1 - the o-ring around the pin centers the pin in the orifice
2 - and most importantly the cradle that the pin rests on, on the electronic side is spring loaded, pushing back up the pin on the side of the electronics.


now if that spring rusts away from under the cradle, then that would be bad.


the oil piston does have some sort of seal, but it is not a normal o-ring, and not replaceable ( some teflon type of seal to ride in the bore).....indeed it is a pretty tight fit in the bore...the bore is metal and I can see how the bore could be worn away a teeny tiny bit .005" or more to no longer seal the gas on the backside of the piston. This would allow a tiny bit of gas to be pushed to the oil chamber (after drawing in oil in to the oil chamber) and force mixing a teeny tiny bit of gas with the oil in the chamber, up to the secondary check valve which allows oil in the fuel mixing area as well as push up on the oil reset pin's piston.

I wonder if OMC thought of that and didn't think was a big deal or expected that from the get go...

I love engineering.


Off to re-do the regulator to stop it from leaking water from below it and re-do the no-oil test....keep you posted..

 

[Bosunsmate]

2 - and most importantly the cradle that the pin rests on, on the electronic side is spring loaded, pushing back up the pin on the side of the electronics.


now if that spring rusts away from under the cradle, then that would be bad.

Ahh got it, this spring is not in the oil side but is on the electronics side of the lever, this is quality info for salt air boaters

Id think OMC figured a tiny bit of fuel leaking in wouldnt be a issue, id agree (so long as no bits of the piston seal got its way into blocking a check valve), i suppose to cover themselves they have that piston down as a maintenance item anyway after so many hours

 

[cfauvel]

re-tested the no-oil circuit after changing the regulator.

https://youtu.be/NWmdAMG7NHM

 

[Bosunsmate]

OH NO that took 4.30min -50 sec equals 3mins forty for alarm to go off.
You say that at 1365 revs that it should go off at just over a minute? why the much longer wait do you think?

 

[cfauvel]

OH NO that took 4.30min -50 sec equals 3mins forty for alarm to go off.
You say that at 1365 revs that it should go off at just over a minute? why the much longer wait do you think?

I think residual oil in the chamber is enough to push the reset pin...


if I had the gumption to remove the cover and re-test I could video the reset pin when the oil is disconnected to see if fires a few more times........BUT I don't LOL


But I should....just for sanity's sake...

 

[Bosunsmate]

Come on, nobody likes a quitter lol
I think that chamber is so small there wont be useful oil in there after a few seconds let alone to equate for all that extra time before the alarm sounds.
Somethings wrong there i suspect maybe in the dividing of the Q13 8192

I actually want you to do another experiment too... please., this would be of great use.
If you warmed up the engine and then stopped it and removed the fuel and oil line from the VRO. Then start the engine back up and start your timer.
Run the engine at the same rev 1365 you did the last test at.
NOW heres the fun part, if the engine stops or starts spluttering high rpms (all those signs of running out of fuel) before 3mins 40 then that means that in practice that there is not sufficient time for the operator to be alerted to a no oil situation. Thats a correct theory isnt it??

You are right, engineering is fun

 

[Bosunsmate]

Actually if you consider that if in the oil line etc ( the residue) that it takes that approx 40 secs for the last reset to happen then if you do 8192/(1365*3) then that would equal approx 2.
I multiplied the 1365 by 3 to show total rpm over 3minutes.
So if you a right about the oil residue adding to about forty seconds for the last reset to happen (VIDEO PLEASE) then if we can figure out what that two represents we have this Rude Goldberg machine solved.

Although you would also need to do the non oil no fuel test to see if at the end of the day crucially the alarm activates in time or not

 

[Bosunsmate]

Ok 2- would that be the two coils for the stator??

 

[cfauvel]

Ok 2- would that be the two coils for the stator??

different topic...but the two coils/windings are
1 - charge coil which produces the 200-400 V (AC I think) to the power packs
2 - ?? coil (I forget the name) that produces something like 20 V (I think that is DC) that goes to the voltage regulator to even it out to about 14V (depending on load) to recharge your batteries and to supply 12+v to all of your accessories.


(UPDATE 07/05/2017 - I misunderstood the question and terminology...to me the 'stator' is the whole unit under the flywheel that supplies both the 200-300 v as well as the 20V to the regulator.
FED corrected me
Stator coil is the low voltage part
and
Charge coil is the high voltage part)

 

[Bosunsmate]

So 8192 is the S13 number.........Actually (1365*3) * 2 equals 8190 :cheer2:

 

[cfauvel]

So 8192 is the S13 number.........Actually (1365*3) * 2 equals 8190 :cheer2:

yeah but I truly believe that the 8192 is correlated to the number of magnets...I have 6 magnets, my Tachometer has a setting in the back where it currently points to a number 6...each magnet has a space, thus a pulse.

8192/6 = 1365

electronics is out of my realm of expertise.


Unless you are thinking that the two coils for the recharging of the batteries comes into play for measuring the tach pulse. That I don't know...

 

[Bosunsmate]

different topic...but the two coils/windings are
1 - charge coil which produces the 200-400 V (AC I think) to the power packs
2 - ?? coil (I forget the name) that produces something like 20 V (I think that is DC) that goes to the voltage regulator to even it out to about 14V (depending on load) to recharge your batteries and to supply 12+v to all of your accessories.

Yes but what im getting at is we know we have to get to 8192 pulses to set off alarm, we know that in three minutes your rpm would get to 4095 so if we times that by two we get 8190.
So what would be the thing that means that the 4095 revs is times by two to get 8190 pulses to set off the alarm, if you have two stator charge coil to your recitifier like my motor does then that could be the answer couldnt it?

This is if you consider that the first forty seconds might be the residual oil in the beginnings of the VRO

 

[Bosunsmate]

Unless you are thinking that the two coils for the recharging of the batteries comes into play for measuring the tach pulse. That I don't know...

Good your thinking cap is still on, yes on mine this is the exact system the tach runs off, have you checked this on yours?

 

[cfauvel]

Actually if you consider that if in the oil line etc ( the residue) that it takes that approx 40 secs for the last reset to happen then if you do 8192/(1365*3) then that would equal approx 2.
I multiplied the 1365 by 3 to show total rpm over 3minutes.
So if you a right about the oil residue adding to about forty seconds for the last reset to happen (VIDEO PLEASE) then if we can figure out what that two represents we have this Rude Goldberg machine solved.

Although you would also need to do the non oil no fuel test to see if at the end of the day crucially the alarm activates in time or not

maybe Friday I'll do another No-oil test.
Run on premix...wait the three minutes until the horn blares.
Turn off the motor.
Turn on the motor with the assumption that the counter is back to 0 when the motor is turned on.
and see if it takes another 3 minutes or just slightly more than 1 minute to blare the horn.


another thing to do too is take off the reset pin's cover and observe the pin when the oil line is disconnected.

not sure if you can see it in the video, but the pin goes from a strong swing to a shallow swing when the oil in the clear tube is used up, then finally stop swinging.

 

[Bosunsmate]

Also your motor starts having signs of a change underway at 2mins19. Theres a slight change in its running status and smoke begins to bellow. It is then that i think your premix has started to hit the carbs, after this your motor is enveloped in smoke until you turn it off. The alarm sounds at 4.30 which is a full two minutes and ten seconds after premix might of entered the carbs.

So if this is the case then this is pretty bad in terms of effectiveness of the alarm and maybe why in the end people have had issues with them

 

[Bosunsmate]

maybe Friday I'll do another No-oil test.
Run on premix...wait the three minutes until the horn blares.
Turn off the motor.
Turn on the motor with the assumption that the counter is back to 0 when the motor is turned on.
and see if it takes another 3 minutes or just slightly more than 1 minute to blare the horn.


another thing to do too is take off the reset pin's cover and observe the pin when the oil line is disconnected.

not sure if you can see it in the video, but the pin goes from a strong swing to a shallow swing when the oil in the clear tube is used up, then finally stop swinging.

I cant see it at the moment, but i take your word on that
I dont think you need to do anything other than run her normally so she is warm so she starts without needing heavy choke. then disconnect both lines and then restart her and the timer, if she cuts out before 340 then thats not good. But looking at your video of when she starts smoking heavily my money would be on her cutting out well short of 3.40

 

[cfauvel]

Also your motor starts having signs of a change underway at 2mins19. Theres a slight change in its running status and smoke begins to bellow. It is then that i think your premix has started to hit the carbs, after this your motor is enveloped in smoke until you turn it off. The alarm sounds at 4.30 which is a full two minutes and ten seconds after premix might of entered the carbs.

So if this is the case then this is pretty bad in terms of effectiveness of the alarm and maybe why in the end people have had issues with them

Not shown or mentioned in the videos or text...when I started the tests I emptied every carb's bowls as I didn't want any NON mixed fuel going to the engine....then I ran the fuel pick up into the pre-mix can and pumped the primer bulb to get premixed gas into the carbs before starting the motor.

I went through nearly two gallons of fuel in the premix...so yesterday's test could have been a little more rich than 50:1 as I didn't empty the gas can when I added more oil and more gas....it is probably closer to 40;1 ....which is probably why it is smoking more.

not off topic, but not having to do with Alarm.....the rate of oil used in the clear vinyl tube seemed excessive at idle....at 800 rpm a inch column should be used in 9 pulses of the oil piston....for me at 1100 rpm I used 1 inch column in about 3 pulses of the oil piston...I need to understand how the two springs in the air motor work and how it releases to allow the piston to snap back to the oil chamber...I'm not getting it at the moment...

UPDATE: the manual states that at WOT the inch column should be used in 3 pulses....that is the rate I am using at idle....hmmm

UPDATE: 7/24/2017 - my manual is from 1986, when the VRO was more lean at idle, than the OMS from 1993 on...My pump is from 1999....looking at a 1999 manual they state that at 1500 rpms a 3 inch column should be used in 6 to 8 pulses.

 

[Bosunsmate]

yeah but I truly believe that the 8192 is correlated to the number of magnets...I have 6 magnets, my Tachometer has a setting in the back where it currently points to a number 6...each magnet has a space, thus a pulse.

8192/6 = 1365

electronics is out of my realm of expertise.


Unless you are thinking that the two coils for the recharging of the batteries comes into play for measuring the tach pulse. That I don't know...

Ive checked the circuit diagram and it definitely comes off the recharging of battery circuit, so that explains the 2multiplier and why it took so long for the alarm to activate. Your tach might run off the other system with six magnets but it seems the VRO does not use that to take the pulse count.
If your tach is taking its reading from the other system then if you swapped that 6 pulse per rev in to the vro input then that would greatly bring down the time to activation and thus give more time to save the engine.
But why has OMC not done this or is your boat wired wrong?

 

[cfauvel]

Ive checked the circuit diagram and it definitely comes off the recharging of battery circuit, so that explains the 2multiplier and why it took so long for the alarm to activate. Your tach might run off the other system with six magnets but it seems the VRO does not use that to take the pulse count.
If your tach is taking its reading from the other system then if you swapped that 6 pulse per rev in to the vro input then that would greatly bring down the time to activation and thus give more time to save the engine.
But why has OMC not done this or is your boat wired wrong?

Good catch on the 2 multiplier

I disagree in part, but agree in part....let me explain.

1 - looking at the electrical circuit the engineer made, you can see that the grey wire is the pulse.
2 - now what I may have been wrong about is the magnets and where the tach pulse is coming from and the whole 6 pole thing on my tachometer...You may be right in that the two coil recharging windings is where the tach pulse is coming from.

I looked under the flywheel just now and found that the Charge Coil has 8 prongs that six magnets would rotate around and the re-charge coil has two prongs like you stated..

so given my potential mistake in the conversion number of 6 (6 magnets), and use 2 (number of prongs/coils for the recharge windings) let's see what we get.

8192 (confirmed by electrical engineer with scope)

8192/ 2 = 4096 revolutions, at 1100 rpm at idle would come out to 3.72 minutes...3 minutes and 43 seconds...as you've come up with...


4096 revolutions is a good minute at normal cruise for me....indeed WHY so long?...why not pick a lower number like 4096 so that at cruise it would fire the alarm in 30 seconds or so..

Can a V6 motor last 1 minute 4096 rpm on the fuel in the bowls?