1985 50hp oil injected hard on gas

[MMHagler]

Are they known for very bad gas mileage? Just filled my 5 gal tank went down the river a couple of times and its down to 1/4 tank. Prop isn't the best,could it be working to hard. Its on a 15ft Thunderbird runabout. Thx for any help/advice

 

[99yam40]

Re: 1985 50hp oil injected hard on gas

What you have written does not tell us anything about how hard you were running it or how long or how far

Just a rule of thumb is you will burn 10% of the rated HP an hour at WOT.
So a 50 hp motor will burn somewhere around 5 gal Per hour at WOT

You can go to Yamaha performance bulletins and see how a rig like yours performed and what prop they used

 

[MMHagler]

Re: 1985 50hp oil injected hard on gas

Thx very much,thats what I needed to know.