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Johnson Outboard vro 1987 omc V4

badcrank 777

Contributing Member
Hello everyone,

I am new here, so bear with me. I just purchased this boat with a Johnson 1987 110TLCUR outboard on it. It was in storage for three years. I'm a auto mechanic but not a outboard mechanic per-say. I drain the gas tank, refilled with new Alcohol free, rebuilt the VRO fuel pump, cleaned and rebuilt the carbs, installed all new hoses, new spark plugs, drained and refilled the lower unit. The primer valve is A-ok. It will start and run for 10 seconds then quit. Found the pressure at the pulse port to low to operate the motor valve in the VRO. So I assumed the leaf valves must be leaking. But upon removing the carbs to remove the intake manifold I noticed a broken recirculation hose that I had previously overlooked.

My question is: Could a open recirculation port drop the pressure to the pulse port enough to cause this low pressure issue to the VRO, because I looked in with a flashlight at the leaf valves and they look very clean and shiny. And did not want to go further if I don't have to. Also is there anywhere one can download a routing diagram of the circulation hose routing for this engine?

I thank very much to all that would respond to this inquiry.

Sincerely,

Badcrank 777
 
As you would suspect, the pressure needed to operate the VRO is supplied by the downward motion of a piston. A blown piston would cause a malfunction of the VRO due to low pressure as well as a broken leaf valve.

Check the compression. What are the psi readings of all numbered cylinders? Standing in back of the engine, facing the spark plugs, the cylinders are numbered as follows:

2.....1
4.....3

If a leaf valve was broken... each down stroke of the piston would result in air being blown out the carburetor throat.

The spark may be perfect... BUT check it anyway. A spark tester where one can set a air gap of 7/16" is necessary. The spark (with all s/plugs removed) should jump that air gap with a strong blue lightning like flame... a strong SNAP! Does it?

The standing starting procedure is: Pump the primer bulb up hard... On that model apply a slight bit of throttle to take it off idle... Turn the key to the START position and push the key in to activate the Fuel Primer Solenoid... When the engine starts, release the key to the ON/RUN position.

The fact that the engine runs for 10 seconds is probably due to the fuel primer solenoid bypassing the carburetors... with the fuel being supplied directly to the intake manifold... fuel NOT flowing thru the carburetors (possibly). This would be due to overlooking the high speed jets that are located horizontally in the bottom center portion of the float chambers, way behind the drain screw. Sitting for that length of time, winterized or not... they're prone to fouling. Best to carefully clean them with a piece of single strand steel wire as solvent just doesn't do that job properly. Fuel must flow freely thru that high speed jet before it can gain passage to any other fuel passageway.

Keep us upgraded.
 
Bad Al is giving you sound advice , I believe it is based on many years of OMC experience.--------Post your compression numbers.------What positve pressure did you see at the pulse port ?-----You might want to remove bypass covers to inspect pistons / rings.-----These motors are world famous for breaking piston rings.
 
An update to my thread. I removed the intake manifold and found two of the leaf blades (valves) not making contact and I could see light through. But they were on the opposite side of the pulse valve cavity. So now I am back to square one, as to why I do not have enough pressure in the pulse valve cavity (only 3 psi) to operate the VRO. There is a small port that instead of being a screw in check valve like the other four, it is pressed right into the intake manifold on the lower right, can anyone tell me its purpose? if it is a check valve I cannot get air through it in eather direction.

Thank you,

Badcrank 777
 

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3 psi will run the VRO pump you may want to look at exactly how the VRO pump works. Seeing light through the reed valves is very common and no cause for concern. Unless the gap is excessive or the valve is bent. But a thin ray of light is not concerning. Have you tried pumping the primer ball while this is happening? Are you still running the actual VRO pump on that motor? If you are you need to change the pulse port nipple out to a pulse limiter. The big port on the intake goes to the air box and reclaims any fuel oil mix that accumulates in the air box, and I believe the 2 smaller ones go the upper bearing with small hoses. Did you rebuild the VRO correctly? Are you using the oil injection? Or did you just rebuild the pump to use it as a pre-mix? Did you connect all the fuel/oil lines up correctly?
 
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This is an update to my quest to get my Johnson J110TLCUR 1978 outboard to run more than 10 seconds off the electric primer valve squirt into the two carbs ventura openings.

The compresion is 100 PSI in all four cylinders, and holds steady with no leak off of pressure after shut down.

The reed valves are tight and new. With all new gaskets on the front side assemblies from air cover back to behind the intake manifold.

The pulse limiter valve is new and is the blue type.

The carburetors are perfectly clean with all passageways and jets perfectly clean with no obstructions.

The VRO has all new parts, and (seams to be) working as it should.

The spark on all four plugs is hot & blue jumping a minimum of 3/8 in.

All the hoses, fuel, oil lines are new and secured with ratchet style clamps, there are no leaks.

The gas in the built in tank is non alcohol and is fresh.

The primer bulb pumps up tight and holds pressure.

The oil warning horn is working as it should.

Everything points to it being fuel related. But what!? I am (as soon as the snow stops flying) going to do one more test, and that is to install a Tee between the VRO gas output port and the distribution rail connecting my vac/pres gauge to the Tee, and see what the pressure is. Before I walk the gangplank! If this is not a head scratcher, I don't know what is!!

Badcrank 777
 
Opinions differ.----I consider 100 PSI to be low for that motor.-----Perhaps test with another gauge.-----Perhaps start the motor with a timing light hooked up to observe behavior of ignition.---Are throttle plates completely CLOSED with control in the neutral position , yes or no ?------Maybe it is NOT a fuel related problem.-----If carburetor bowls are full the motor will run for more than 10 seconds on that fuel.-----Are the carburetor bowls metal or plastic ?
 
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The carburetor bowls are metal (aluminum)

The throttle plates are closed and yes the shifter is in neutral. But using the idle lever to start the motor, they are open just a crack.

The compression gauge is brand new (I never used it after I purchased it long ago) and it of the type that has the screw in connectors with O rings to the cylinder port.

I do have a timing light (new) and will do as you say, but it will be a while for right now we 8^ outside and it is snowing. This Sunday will be back to 60^ that will give me a chance to perform what you say.

Being new to this 1978 110 Johnson outboard, I have no idea what the (normal) compression should be, but what seems promising to me is that the compression of 100 PSI is consistent in all four cylinders. In my way of thinking, if a cylinder was bad it would show a decrease in pressure or would not hold pressure if there was a broken ring issue. When it is started the RPM's rev up there and are strong. One other thing is if I advance the idle lever to max up position the motor revs up very fast and quits almost as fast. But if I only advance it half way, then it will run for the 10 seconds because of the decreased carb valve plates being almost closed.

One other thing is I did take a spray bottle with a 50.1 mix and if continued spraying in the mouth of the carbs air side the motor would continue to run as long as I kept spraying the mix.
 
Yes I agree. But in frustration I went ahead and removed the carburetors for the second time, and went all the way through them. I am 100% certain they are not the culprit. One other thing I done after I found a split hose in the pickup tube in the built in gas tank, was to refurbish that with all brand new all they way to the primer bulb. After which I depressed the check valve on the other side of the primer bulb and made sure that I had a solid fuel flow.

I will update, this coming Sun. after I see what the PSI rating on the inserted Tee between the VRO output and the fuel rail to the carbs is.

Thank you so much for you guidance, info and response to my delima.

Badcrank 777

P.S I had a Mercury 1000 100 HP that had been setting for 20 years, outside. with no winterizing etc. I went through the carbs, put in new plugs, applied fresh gas mix and it started first time, and I have been running it on my other boat just fine. This my first experience with a Johnson, and I am baffled. Of course it is a little more sophisticated than that old Merc.
 
I have hit a brick wall on this engine. I have found that there is no fuel issue, the pump is working perfectly, there is no spark issue it's hot and blue and will jump a min of 1/2 inch. The primer bulb pumps up tight and has no leak down. The carbs are super clean and working as they should, all four cylinders test over 90 psi and are all equal.

So I have a question. since there is nothing else to check or do.

Is it possible that the oiling mechanism in the VRO (do to age) this motor is a 1987. That it is injecting to much oil into the mixing chamber of the fuel pump and fouling out the plugs and that is why it sputters after starting up and then quits after about 10 to 15 seconds?

Thank you for you answer.

Badcrank 777
 
Did you actually clean the four (4) high speed jets manually with the blunt end (not pointed) of a piece of single strand steel wire? That is "all" four of the high speed jets located way in back of the four (4) drain screws?

Also, clean with a smaller diameter piece of single strand steel wire the four very small offset idle feed tubes that are located off center within the four (4) vertical high speed nozzles.
 
No I didn't even take out the drain (4) plugs on the float bowls, I did however manually remove all the other jets and made sure they were all very clean, and the idle feed tubes I did after cleaning, took a red spray nozzle attached to a can of "gumout" and when sprayed into those feed tubes the spray came out the other end clean and smooth. So I assumed they are free of any obstruction or built up oil etc.

I will in the morning, take out the carbs and make sure of those jets behind the drain screws are clean.

Thank you,
 
As Racer said carbs need revisited...Complete disassembly , clean all passages and run small wire thru them and NEW gaskets!! Do not reuse old ones. The idle and emulsion tubes can still pass carb spray cleaner and STILL be partiality obstructed, this makes a lean setting.
 
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Post # 11 says that you " went all the way through them "----Those carburetors.-----Now in post # 14 you say you did not remove the drain plugs to look for / inspect / clean the orifice plugs ( high speed jets )-----Kinda makes one wonder does it not ????
 
Yes I know what you mean. But honestly I never suspected there was jets behind the drain plugs. When I went all the way through them I removed everything except the drain plugs, dropped the bodys in "gunk" carburetor cleaner, the after a water wash & compressor air drying them, continued with "gumout" spray on all the jets etc. But like I say never knew there were jets behind the drain plugs. I am hard pressed to understand that if there was any gunk in the jets, that the Cleaner bath would not dissolve anything after soaking for over an hour. But I guess anything is possible.

Badcrank 777
 
One other thing I do have "new" gasket, so I will used them. also "Faztbullet" You say a lean mixture, but what I am noticing upon start up, is a lot of blue smoke (more than normal) and after removing the "new" plugs I see them coated in oil and wet, which led me to believe the VRO was malfunctioning and inserting way over the 100.1 mix at idle causing it to sputter and die after 10 sec. Because to much oil will for sure foul out the plugs and will not allow the motor to idle properly. What I was going to do is purge the fuel system from the intake gas port on the motor housing, connect my primer squeeze bulb and hose to my premix (50.1) portable tank from my other boat, disconnect the oil line from the VRO, short the electrical plug so the horn won't sound and I can start the engine, and see if it will run, on a true 50.1 gas mix. And if it does then that will for sure point to a bad VRO oil injection issue. If not then it's back to the carbs, and I will sure do everything you folks are telling me on the jets.

Thank you so much for all this valuable information, it is sure appreciated! For this motor is driving me crazy and eating my lunch!
 
Those cleaning solutions are designed to clean out old gasoline deposits. Could be a small piece of anything stuck in those jets. I had a small piece of old shredded packing in mine this year.
 
This is very good to know! It was unfortunate that I overlooked those jets behind the drain screws, for I have had those carbs apart two times, but like they say "third time's a charm" :) And after this boat & motor was in storage for three years, prior to me purchasing it, stands to reason so many things could be the culprit of it not stay running. I have found so many things i.e. cracked suction tube in the built in gas tank, solidified oil in the carbs, etc, that is why I replaced all the hoses, installed new spark plugs, rebuilt the VRO, installed new primer squeeze bulb and connections, checked the compression, It just frustrating after all I have done and the thing just defies me by not setting there and idling away. So today I will revisit the carbs, and try my 50.1 premix experiment, after purging the system and disconnecting the oil feed to the VRO. And if none of this works, I will be up the creek without the preverbal paddle.

Badcrank 777
 
IT's RUNNING. Problem Solved!!

I want to personally thank everyone who responded to this thread and all your input. I was chasing ghosts, because of overlooking the fast idle jets when i first worked on the carbs. I was so focused on the main body of the carb and the metering tubes, I didn't even know there was those four jets in the bottom of the float bowl plate. Lesson learned!! Anyway they were for shure plugged, because of the motor setting in storage for three years.


It starts and runs like a dream. Now the last remaining issue, is after running for about a minute, the warning buzzer starts beeping off & on every sec indicating no oil flow. I am reasonably sure there is oil being mixed at the VRO. I purged the line of any air and the oil from the reservoir is flowing freely up to the connection of the VRO. I also primed the bulb on the oil line once connected to the VRO. I shut the motor off right away when the buzzer comes on, in fear of no lubrication to the motor. Anything I could look for in this issue.

Thank you all so much,

Badcrank 777
 

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No such thing as a "fast idle jet".... Although their actually an orifice, they're referred to as a "High Speed Jet".

Glad you finally got it.

This where we all join in and say "Told You So". :)
 
Yes, I will except the "I told you so" it is fitting for someone who could not see the forest for the trees,:eek: and more importantly would not pay heed to what you all were saying in the first place. Yes I ment High Speed Jet, after three weeks and many dead ends my brain was rattled. But so happy I'm not tearing this motor down, when all it was was clogged jets. I if all goes well might be able to squeeze in one or to days at the lake, before the snow flies and we are all waiting until next season rolls around.

Thanks,
 
Post #1 said you were a " mechanic " and that you had " cleaned and rebuilt " the carburetors.-----Now we know the real story and it has been told many times over.---Not uncommon for folks to be baffled by these simple carburetors.----Sorry, I had to say it
 
I want to personally thank everyone who responded to this thread and all your input
Thank you all so much, Badcrank 777

And I think I speak for most of us when I say "You're Most Welcome". And hope that your engine stays trouble free for your next boating season.

When switching from automotive mechanics, which possibly you're familiar with, to a two cycle setup, even the simple things can be confusing at first... just takes a little time.
 
I wholeheartedly agree. 2 cycle is a bit different animal, as opposed to 4 cycle engines, of which I am very familiar with. It is a learning curve to be sure, but after this adventure, I sure have learned a lot that I didn't know previously. At least about the fuel delivery system, VRO, oil delivery and spark. I don't think I would ever want to tackle the piston side of a 2 cycle, this was enough to last me for awhile.

A big thank you to all!

Badcrank 777

Sailing into the sunset!
 
There is a specific way to prime a VRO pump.
#1 Disconnect the oil line from the pump itself.
#2Then pump 16 oz of oil out of that line
#3 run a 50-1 mix from a tank to the motor
#4 Start the motor and wait for the alarm to go off.
#5 once the alarm goes starts sounding put the oil line back on and pump the ball once.
#6 wait for alarm to turn off.
If the alarm does not turn off then you have a oil side pump or sensor issue. Start running premix until you know for sure.
 
Thank you, Flyingscott.

Here is what I found. I disconnected the oil line from the VRO and found an air pocket in the line right where it connects. So I installed about 12 inches of clear hose to the VRO clamped it, held it upwards, filled it with 2 cycle oil marked on the hose with a marker, started the engine, and the VRO is pulling the oil in and woking. Also no alarm, and the engine is purring like a kitten.

So knowing this, I am replacing the the hose all the way from the oil reservoir to the VRO. The old one on there was super hard and brittle, so a new hose is in order. Once I install the new hose I will work the primer bulb until I have oil flowing at the end, then connect it to the VRO. After which I will follow your priming instructions for the VRO. Will report back, after I do this procedure today.

Thank you.
 
If I was replacing the hose I would replace the tank and all. I believe the hose ,sending unit and filter are around a $150. A new tank assembly with everything is $200
 
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