VRO Question

cvx35

Petty Officer 2nd Class
Joined
Jan 13, 2004
Messages
103
This past spring-you know, "carburetor cleaning season". We ran into 5 or 6 cases where the oil had purged into the carburetors after sitting through the winter. Any suggestions about oil tank ventilation? We've not seen this problem until this year. Different year models and horsepowers. We've been suggesting to just crack the lid on the VRO tank after using the boat. Is this a bad idea? <br /> Thanks
 

Joe Reeves

Supreme Mariner
Joined
Feb 24, 2002
Messages
13,262
Re: VRO Question

No need to crack the cap as it is vented, otherwise oil would be prevented from leaving the tank in the first place.<br /><br />Check with the owners of those few rigs to see if they're in the habit of running the engine out of fuel (gas). If so, as the engine runs low on fuel (gas), the VRO will load the carburetors with oil.<br /><br />Obviuously the above will cause the engine to stop running and if the engine is being stored for the winter, the owner would be none the wiser until, as you have stated above, he/she attempts to start it once again.
 

DHPMARINE

Captain
Joined
Dec 16, 2003
Messages
3,688
Re: VRO Question

Joe,<br /><br />If the fuel is stabilized,and the motor is run out of gas,,does this winterize the motor engine-wise <br />/<br /><br />DHP
 

DHPMARINE

Captain
Joined
Dec 16, 2003
Messages
3,688
Re: VRO Question

Joe,<br /><br />If the fuel is stabilized,and the motor is run out of gas,,does this winterize the motor engine-wise <br />/<br /><br />DHP
 

seahorse5

Rear Admiral
Joined
Jan 24, 2002
Messages
4,698
Re: VRO Question

The "VRO" oil cap has a spring loaded rubber vent valve inside the cap. It will vent when a small vacuum occurs as oil is consumed, but will seal and hold pressure if there is a pressure buildup, as with a warmer temperature change. <br /><br />Normally a working oil check valve with hold against the pressure inside an oil tank, but with age, deterioration, or debris, the inlet check valve can leak and allow oil to migrate into the fuel pump chamber of the motor and mix with fuel as its "pushed" up into the carbs.<br /><br />Straighten a paper clip and using side cutters, cut at a diagonal with will leave a sharp end on the clip. Press the sharp end up thru the vent hole on the underside of the oil tank cap and you will feel it pierce the rubber "needle valve". Now the cap will vent for pressure as well as vacuum.<br /><br />If an oil tank is mounted higher than the motor, you can also get a siphoning action or the same it a boat is tilted up high in the front.
 
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