Evinrude 4 wire VRO

[thestoops]

I have just installed a 4 wire VRO replacing my 3 wire. I understand the 4th wire is for a no oiling condition. How is the no oil condition sensed? <br /><br />Also I have been told the fuel to oil ratio is no longer 50:1 to as low as 150:1. Does any one know what the ratio is given the throttle position?<br /><br />Thanks for any help on this.<br />D

 

[Cricket Too]

Re: Evinrude 4 wire VRO

Fisherman....I'm not really sure how they go about sensing the no oiling condition, but as far as the oiling ratio goes it is not 150:1, it's probably not even 100:1, the new pumps are not VRO anymore they are called OMS(Oil Metering System) and oil at 50:1 all the time, possibly a little bit higher like 75:1 at idle. I don't think there is any older 2 cycle that runs 150:1. Deffinetely a good choice swithching to the new 4 wire system, much safer. Good Luck.

 

[seahorse5]

Re: Evinrude 4 wire VRO

The 3 wire pump used the AC or pulsing DC voltage (depending on model engine) to power the logic dhips on the warning system. The 4 wire pump uses the purple wire for a constant 12V from the key switch for power, making it a more reliable system.<br /><br />Since 1992, the OMS pumps run about 75:1 at idle and close to 50:1 at high speeds. Generally a boater will average about 60:1.