Fuel consumption 30hp 2stroke

[Thumperbob]

Currently have a manual 30hp 2 stroke Mariner on a SR4 with underconsole 25l fuel tank.
Am trying to establish what sort of fuel consumption I can expect - been too busy having fun in past to record, just keep topping up!
Now an issue as beginning to plan (not too) longer cruises, eg forthcoming one up River Clyde to Glasgow city centre and to plan for additional fuel tank etc.
Would be running with one adult & junior at most.

Any ideas?

[Nos4r2]

Originally Posted by Thumperbob

Currently have a manual 30hp 2 stroke Mariner on a SR4 with underconsole 25l fuel tank.
Am trying to establish what sort of fuel consumption I can expect - been too busy having fun in past to record, just keep topping up!
Now an issue as beginning to plan (not too) longer cruises, eg forthcoming one up River Clyde to Glasgow city centre and to plan for additional fuel tank etc.
Would be running with one adult & junior at most.

Any ideas?

Around 3 gallons per hour at WOT.

[Turbodiesel]

Approx 10ltrs an hour at Wide Open throttle. Its usually worked by taking a third of the horse power at wide open throttle. Opti's and four strokes are about a third of that figure again. So a 30 4 stroke would be about 6.7ltr an hour at wide open throttle.

[Polwart]

Originally Posted by Turbodiesel

Approx 10ltrs an hour at Wide Open throttle. Its usually worked by taking a third of the horse power at wide open throttle. Opti's and four strokes are about a third of that figure again. So a 30 4 stroke would be about 6.7ltr an hour at wide open throttle.

I don't think thats what you meant (cos then it would only use 3.3L/h which would be impressive) I think you meant a third less again.

[Channel Ribs]

Originally Posted by Thumperbob

Am trying to establish what sort of fuel consumption I can expect - been too busy having fun in past to record, just keep topping up!

That engine in good order should use 13 Ltrs/hour at full throttle, you should expect to be able to cruise at just over half that though.

[Doug Stormforce]

Totally agree with Turbos maths, As Polwart has already corrected the four stroke is 2/3 of 1/3 of HP at WOT.

This engine however is near enough 10l/hour at full throttle

[Locozodiac]

Originally Posted by Thumperbob

Currently have a manual 30hp 2 stroke Mariner on a SR4 with underconsole 25l fuel tank.
Am trying to establish what sort of fuel consumption I can expect - been too busy having fun in past to record, just keep topping up!
Now an issue as beginning to plan (not too) longer cruises, eg forthcoming one up River Clyde to Glasgow city centre and to plan for additional fuel tank etc.
Would be running with one adult & junior at most.

Any ideas?

If it's a rebadged Tohatsu the consumption is: 3.96 Gl/H or 15 Ltr/Hour at WOT, will depend on sea conditions, boat weight, wind, etc. Going 1/2 to 3/4 throttle will be the way to go optimizing fuel comsumption/travelled distance.

Happy Boating

[Turbodiesel]

Originally Posted by Polwart

I don't think thats what you meant (cos then it would only use 3.3L/h which would be impressive) I think you meant a third less again.

Oh Yes, soz my poor head cant do calculations and type at the same time!!