CONTINUOUSWAVE

I have a VRO2 OMS pump on a 2003 60 degree V4 looper that seems to be over-oiling, causing smoky exhaust and poor running. I read the excellent article on CW by Bill Gannis on the VRO. I am rebuilding the VRO-fuel pump. 2003 is technically OMS pump but everybody still calls it "VRO."

I disassembled it, including the oiler side, before I read the part "do not disassemble." There is a large parabolic O-ring in good shape, with an obvious cavity to put it. There is a fat blue O-ring that attaches to a short metal shaft which is part of the sensor system for oiling. Although I couldn't find good details in an online search, there appears to be a vertical shaft that moves up and down with each piston pulse, contacting the horizontal shaft mentioned above. The count from the motion of the latter, signals amount of oil flow, and the alarm stays silent (and vice versa). Did not see any other o-rings, but might have dropped it while disassembling.

So far so good. However the diagram below seems to show a different O-ring on the oiler side (all the below links are from same source - so should not be conflicting, but they are). See little O-ring [callout 22] in red:

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But the kit shows a blue O-ring that is a perfect fit for that oil-side sensor shaft above, except the kit says DO NOT disassemble oil side.



Is there another O-ring--maybe this one--that is supposed to be on the oiler side?

The blue O-ring in the kit is probably callout-9 in the illustration.

O-ring may be and certainly appears to be 22 but since seal 19 is not included it would wise not to disassemble that side. If already apart I'd want to replace 19 too. Their note also says you'll have parts left over.
....

do yourself a favor and disable the oil feature of the pump and premix. The #1 destroyer of every OMC motor after 1985 (when first introduced) is a failed VRO pump that is clogged, or mistakes water/condensation in the gas as oil.

It's really easy to do and all you have to do is pour in your TCW-3 at each fill up for peace of mind.

I work on about 250 OMC motors a year and specialize in everything that is carbureted by them.

And apparently the word K.I.L.L.E.R. gets converted to 'great' in this forum. LAME. Tried to say "the #1 INSERT WORD HERE of every OMC motor...." and saw this substitution. Weird.