Evinrude vro

[jlrjoz]

I have a 96/97 evinrude vro. After i bought the boat three years ago i freaked out after reading a few horror stories about VRO's. But after some research i was assured that these stories were on earlier models. On another thread somebody suggested that I plug the oil injection and mix the oil by the tank. Is there preventative maintenance for this injection system?

[bigturk_80]

I had an older model VRO, a 115hp that I disconnected the oil pump on. The motor gave me great years of service after that, and is still running for the guy I sold the boat to 4 years ago.

The problem with the VRO's is the design itself. Variable Ratio Oil means just that, it's getting a different rate of oil at different throttle settings. All other oil injectors basically mix the fuel at a ratio of 50:1 no matter what throttle setting you are at. With the VRO, you can be running as lean as 100:1 or even less at idle to 1/4 throttle setting.

Personally I'd rather foul the odd spark plug than have to replace pistons and crank seals. If you keep the oil pump, and continue to run it as it came from the factory, I would recommend not staying at idle to 1/4 throttle for very long at any given time. Get it up to a higher throttle so it's getting that rich mixture.

[IRon]

Same here. I've got a '95/130 with the same VRO system. I've already had trouble with fuel delivery and had to rebuild the fuel pump side of it. I just don't trust the system on it after 17 years. I don't troll with it, I've got my 9.9 Evinrude for that and it's pre-mix. I think I'll just simplify it and make them both pre-mix for my own peace of mind.

[bigturk_80]

They're decent motors, they just have a poor oil delivery design. There is no reason to cut the oil mixture back so far at low rpm, I don't know whey they ever designed it that way. I'd rather have a bit of low speed oil load up and a bit of smoke over a rebuild.

On that note, I have a perfectly good VRO oil pump if anyone wants one!

[Miss em]

I disconnected the VRO in a 110 OMC I had a few years back. Ran pre-mixed 93 Octane and Amsoil and never had a lick of problems with fouled plugs. One set of plugs would easily go all season.