1990 Johnson 90 HP VRO

[lakesmodified]

I recently purchased a 1990 Johnson VRO 90 HP engine for my 24' TOON. I'm going to be hanging it this coming week and wanted to know which way to go with the OIL INJECTION? I've noticed quite a few complaints about the Johnson/Evinrude systems, and wanted to know what's the best way to go. If I do remove it, I guess I have to replace the "Dual" fuel/oil injection pump with a single fuel pump from a 1990 88 HP engine, is this correct? What lines will need to be plugged, and how do I dis-arm the low oil warning horn? If I decide to leave the oil injection, is the tank vented, or should there be a line coming off the engine to pressurize the oild tank? Thanks in advance guys..

[Capt.Insane-o]

We have had a **** pile of problems this spring with vro's and those motors. Put a brand new one out of the box that refused to pump any fuel, noticed when I reordered for stock the pump was super'd to 5007448 for those motors. That one seems to work fine. Personally I think the system and it's electronics sucks. If I owned one of those motors it would have a carter marine pump and pre mix. There is a wire that needs to be cut or disconnected to disarm the warning system. Also the tank has no pressure running to it, it's a pump draw system. They are really a fine running motor when everything is right.

[MattGreen]

If you want to get rid of the VRO, it's very easy. The VRO unit is actually 2 separate pumps in one, so you can disconnect the oil side and still leave the fuel side. The fuel side is very reliable, the oil side......:rolleyes:
To disconnect the oil injection and go to premix:

1) disconnect the oil line to the pump and remove the rest of the oil line/tank assembly.

2) Install a block-off plug on the oil inlet to the pump. I forget the P/N, but BOMB/OMC makes a plug specifically for this.

3) unplug the wiring harness that goes to the pump

4) disconnect and tape off the wiring that goes to the oil tank sender

There really isn't a need to go to an electric pump on a stock motor. If you are fixated on removing the VRO system completely, you can go back to the older 3-hose diaphram fuel-only pump that was standard before VRO came around. These pumps are still available and are also very reliable.

And yes, those are good motors as long as you understand their limitations.

Matt

[lakesmodified]

Thanks guys, so I guess the concensus is to get rid of the VRO oil injection... Now, this is a pontoon installation, so it's not like I'm looking for a high HP engine, so would you bypass the VRO section of the pump, or get the separate fuel pump that doesn't have the oil injection? I want the most reliable set-up here. I don't want to mess with this engine once it's hanging on the rear of my 24 FT TOON....

[83PREDICTOR]

Would this apply to my 1992 115 Johnson also?

[David]

I'd keep the VRO. It's run fine on my brother's 200 since 1989. And the 100 that I pick up tomorrow has VRO.

[ROLF]

VRO in Latin means "Very Rarely Oils" ditch this system on any and all OMC motors you will recieve NO warning before failure, just a death rattle.I lost two motors from this and about a dozen on my lake meet the same untimely
demise.Retain the pump/disconnect the oiling and premix,you CANT loose by premixing.

[MattGreen]

If you want to still have oil injection, just get yourself a brand new pump, they're in the neighbourhood of $ 300, and are really easy to install. The shop I used to work at had a policy of suggesting VRO pump replacement every 5 years as a way of preventing what ROLF just mentioned. This applied to all VROs, not just crossflow motors (they're all basically the same pump anyways). We had an excellent success rate with this. Old VROs that are still used for oiling are risky business....

Pay a little now, or a LOT later....

Matt

[lakesmodified]

Thanks everyone for your input... I guess the best thing here is ditch the VRO and just pre-mix like I do on my 2.4 Offshore. Needless to say, keeping the VRO by buying a $300 pump isn't worth the money spent. Thanks again, Ivan

[CALVIN]

Will disconnecting the oil side of a vro and using the fuel side result in premature wear in the diaphram of the fuel or oil side?

[bigboy]

I bought a premix pump for my V4.

I'm very happy with it!

It's like an original pump but less the vro part. If you just disconnect the oil of a vro pomp it will stop working within a few years...

[MattGreen]

From the experience I gained, I don't recall seeing oil-disconnected VROs failing on the fuel side more often than oiling VROs. In fact, I've definitely seen oiling VROs fail to deliver sufficent fuel at WOT, as well as oiling VROs grossly over-oiling ("mosquito-killing").

It's worth mentioning that the pump itself is only part of the fuel system equation, and having adequate lines, filters, tanks, vent, and anti-siphon valves are just as important to having a reliable motor as which pump you choose to run. Seen some horror shows....:rolleyes: and I didn't work in this field nearly as long as other people on the board.

Matt

[bigboy]

I heard that years ago there was a kit to go to premix. You had to screw the oil part of and place a steel plate instead off it!

You could order this years ago but now not anymore!