1996 175 Yamaha v6 2 stroke

[rocket ron]

Can any one tell me if there is a product or a conversion that will improve the fuel ecomny on the 175, its only done about 150 hrs, its mounted on a 5.85 streaker tournament with a 170 ltr fuel tank. Any information would be great.
Rocket Ron

[Ballymac]

Best fuel economy is realized in a finely tuned engine with correct timing. Assuming that's the case, what size is your prop? Depending on your boating habits, i.e. speed, skiiing, casual; a prop can have a big impact on fuel economy.

[rocket ron]

Yeah good point, i had a look but cant find any numbers on the prop, its probably the same age as the motor, i use it for fishing, i will look into the better prop as this one is a 3 blade, wether or not a 4 blade with a trim is better??

[yamatech43]

No, most efficient props are 3 blades....ballymac is referring more to a sweet spot in pitch/diameter that will give you the most thrust without making the engine work harder than necessary to spin.....sort of like a car's gears...if you have a light enough and 'skinny' enough boat you might get away with say....a 24" pitch but on most boats you would max out at a 21" pitch....remember to always use a prop that allows the engine to reach max rpm at w.o.t. for engine longevity. You can usually borrow props from a prop shop(loaners) to try and find best blend. And like he said....a good linc & sync and tune up and properly trimming motor are big factors.

[rocket ron]

ok ,what im really trying to do is to be able to skip through the islands through queensland which is a 64 mile return trip & thats without fishing ,so about 100 mile would be a safe trip.

[99yam40]

Have you looked at the prop with it off the motor? They are stamped on the inside of hub sometimes.

Have you tried looking at this web site to see if you can find something close to what you are running?
They give MPG at different RPM, but probable will not show something of that age. With a 40 to 45 gal tank you should be able to make 100 miles with plenty for reserve if you can keep the consumption down to around 3 MPG
http://www.yamaha-motor.com/outboard/products/perfbull.aspx?ls=outboard

[rocket ron]

yeah thanks i had a look at that link, it doesnt go back to the age of the motor, but thanks anyway