1996 Johnson 130 builds up oil in the fuel filter and carbs. Should I ditch the VRO?

[kvdsr]

Bought the motor last year and it would crank but not start. I drained the carbs and replaced the fuel filter, and found mostly oil in them. Pumped new gas into the lines via the fuel bulb and it started and ran well with the muffs on. Then I put it away for the Wisconsin winter.

Didn't get a chance to run the motor again until this week. Again, the carbs and fuel filter are full of mostly oil.

I'm thinking about just running premix in my tanks and disconnecting the VRO. Good idea or bad? If yes, how do you take the VRO out of service?

 

[jakedaawg]

The VRO is fine most likely. The carbs and such are full of oil because someone disconnected the fuel and ran the motor dry. Thats what they do, they keep pumping oil even if there is no gas to mix it with. If it is overoiling while running you have either a fuel restriction or an air leak.

Others will disagree, but a WELL MAINTAINED, modern 4 wire VRO pump is an incredibly reliable oiling system that has gotten a bad name from folks who do not quite understand it completely. It does require maintenance. You need good oil and fuel lines and connections. A clean oil tank. Periodic testing. Wires that are free from corrosion. etc...

If this is basically new to you you should inspect/replace fuel lines anyways. They are 20 years old.

 

[kvdsr]

I can't speak to what happened to cause the oil glut before I bought it last year. But after I got it started and running last fall I fogged it while it was running, let it stall out, turned it off, and then put it away with the gas and VRO still connected. I looked at the clear fuel filter, and the gas was fine.

This year I cranked and choked it for a total of maybe two or three minutes. I looked at the fuel filter and it was full of dark oil, I drained the carbs and almost pure oil came out of them.

I will be using the boat infrequently, sometimes it will be sitting for a month before use over the season. I really don't want to deal with having to flush oil out every time it sits for a while.

Thanks for the reply ... Ken

 

[flyingscott]

Look for any air leaks in the fuel system as that can cause over oiling. Especially look at the plastic clamps that hold the hoses. You can also look at the cap on the oil tank if the vent is plugged it can push oil into the fuel system.

 

[clemsonfor]

Run the boat on the lake like you would and then put it up 2 weeks and try to restart. See if the oil issue returns? Need to make sure it repeats itself. Could be over oiling? How bad does it smoke at idle and then say on a plane warm?

 

[Joe Reeves]

I've never heard of such an installation... BUT... by any chance, is the oil tank installed higher than the engine?

Also... if the "Anti Siphon" valve at the fuel tank (the fitting that the fuel hose connects to) is stuck open, is not present, or has had the inner workings discarded (reducing it to a plain clear fitting, that would allow the fuel at the engine drain back into the fuel tank. How oil might fill those empty fuel lines is a unknown to me at the moment... BUT...if it were me, I'd inspect that valve.

********************
(Fuel Anti Siphon Valve)
(J. Reeves)

Many of the later OMC V/6 engines incorporate a fuel restriction warning via a vacuum device attached to the powerhead. If the engine overheats, or if you have a fuel restriction, the warning is the same.... a steady constant beep.

NOTE... Only the V/6 & V/8 engines have the above "Fuel Restriction Warning". The warning horn will not sound on the other models.

The fact that a engine is not overheating, but the warning horn sounds off with a constant steady beep, and that the rpms drop drastically would indicate that the engine is starving for fuel due to a fuel restriction. Check the built in fuel tank where the rubber fuel line attaches to the tank fitting. That fitting is in all probability a "Anti Siphon" valve which is notorious for sticking in a semi closed position. It will be aluminum, about 2" long, and the insides of it will consist of a spring, a ball, and a ball seat. If this valve exists, remove it, knock out those inner components which will convert it to a straight through fitting, then re-install it. Hopefully that cures the problem.

The above procedure will cure a restriction problem with the anti siphon valve as stated. BUT, it may also allow fuel to drain backwards to the fuel tank when the engine is not running (siphoning backwards) due to the fact that the carburetors/fuel pump etc are higher than the fuel tank. This condition is not an absolute as the valves in the fuel primer bulb usually prevent this backwards siphoning problem. However.... if this does take place, the cure would be to install a new anti siphon valve.

NOTE: There has been cases when the output valve in the fuel primer bulb would come apart, and the inner portion of the valve would actually reverse itself and be drawn back into the primer bulb's output valve body. This in effect would create a shut off valve and result in a fuel restriction. If this is the case, you should be able to feel something laying in the bottom of the primer bulb when held horizontally.

 

[kvdsr]

Okay ... I checked the gas tank fittings & line and did find a small leak at a bulb connection when I pump it. I replaced the bulb last year and used hose clamps, but must not have tightened it properly.

I looked at the oil tank and saw three "openings" on the top. One of them is the fill port, and I checked the cap and it was tight. Another one had a line coming out of it to a bulb and then to the motor. The last one had a rubber "nipple" plastic-clamped over a plastic tube - the nipple had corroded over the years and was basically falling off. When I replace the nipple and the tiny plastic clamp what should I ask for and where would I find it? Is that nipple possibly the smoking gun?

The oil tank is on a pontoon boat, so it would be somewhat higher than otherwise.

I'll be premixing the gas until I see how my fixes work out - good idea? I'm also considering vise-gripping the oil line off when I'm not using the boat.

Many thanks to all of you ... Ken

 

[kvdsr]

Speaking of nipples and smoking guns .... I'm trying to recall the spy movie in which one of the babes has a bra that fires bullets in the direction she points her ... ahem....

Sorry for the distraction .....

 

[flyingscott]

Do not clamp the oil line like that. Put up a pic of the top of the tank the vent is in the fill cap.

 

[kvdsr]

No Title

Here's the pic ... you can see the deteriorated nipple on the bottom left being held in place with a small plastic hose clamp.

 

[kvdsr]

The more I'm thinking about this situation, the more I'm leaning toward getting rid of the VRO system. It's pretty old, it's giving me problems, I don't like giving up the space for the oil tank & lines, and a failure could be disastrous.

Thank you all for your replies and help. I will start another topic on how to get rid of the VRO on my engine.

 

[dingbat]

It sounds like an issue with your OMS.

A failing OMS (leaking diaphragm, leaking check valve) will over oil the fuel. Same for a vacuum leak on the fuel side.

Have you run the tests outlined in the Service manual to rule out a vacuum leak on the fuel side? Have you tested the OMS itself?

Going to premix doesn't solve the problem of a failing fuel pump.

 

[boobie]

Replace the oil tank cap. It's not venting properly.

 

[kvdsr]

Thanks for all the help.

 

[boobie]

Or just leave it loose and out of the weather when storing it.

 

[Joe Reeves]

I'm thinking about just running premix in my tanks and disconnecting the VRO. Good idea or bad? If yes, how do you take the VRO out of service?

(VRO Pump Conversion To Straight Fuel Pump)
(J. Reeves)

You can convert the VRO pump into a straight fuel pump, eliminating the oil tank and VRO pump warning system, but retain the overheat warning setup (and fuel restriction warning if so equipped) by doing the following:

1 - Cut and plug the oil line at the engine so that the oil side of the VRO pump will not draw air into its system. Trace the wires from the back of the VRO to its rubber plug (electrical plug) and disconnect it.

2 - Trace the two wires from the oil tank to the engine, disconnect those two wires, then remove them and the oil tank.

3 - Mix the 50/1 oil in the proper amount with whatever quantity fuel you have. Disconnect the fuel line at the engine. Pump the fuel primer bulb until fuel exits that hose with the tint of whatever oil you used. Reconnect the fuel hose.

That's it. If you want to test the heat warning system to ease your mind, have the key in the on position, then ground out the tan heat sensor wire that you'll find protruding from the cylinder head. The warning horn should sound off.

 

[cfauvel]

It sounds like an issue with your OMS.

A failing OMS (leaking diaphragm, leaking check valve) will over oil the fuel. Same for a vacuum leak on the fuel side.

Have you run the tests outlined in the Service manual to rule out a vacuum leak on the fuel side? Have you tested the OMS itself?

Going to premix doesn't solve the problem of a failing fuel pump.

Spot on...

I calculated the ratio on a long trip recently to be 18:1(measured the oil left after filling the tank with known quantity and used my gas flowmeter for fuel used....there is a margin of error on the flow meter as I haven't tested it for accuracy)

Did the flowchart tests for the OMS and it failed one of the tests ...told me to replace the fuel diaphragm....whilst I could not see anything (no rips or tears), replacing it DID pass the test that failed previously... what I surmise is that the brown flapper in the fuel side wasn't sealing nicely against the plastic slots of the fuel diaphragm, thus popping the poppet releasing the vacuum on the other side and shooting oil more often. We'll see after this Friday how it does on oil consumption.

too bad the various check valves are not serviceable. .