Oil use

[2kvert]

Hey all,
We recently purchased a pontoon with an Evinrude 250 HO.
We've gone thru what seems like a lot of oil in this thing it has a tank that's about a gallon and we've refilled it 3 times. Can anyone tell me what is normal? We have a 40 gallon fuel tank. I had thought someone told me that the oil would last a few tanks bit that doesn't seem to be the case.
Also, does the ratio stay consistent from easy to hard use?
TIA

 

[racerone]

If this is an E-TECH motor then the computer ( ECU ) injects oil into the engine ( NOT into the gasoline ) as it sees fit.----Based on sensor inputs such as RPM and throttle position.

 

[Chris1956]

If carb or EFI motor, expect about 50::1 gasoline to oil. So about 3 qts per 40 Gal gasoline.