Normal speed at full blast?

[Jaynen]

Round 2 of testing the engine. Got the 15' boat up to 42kms/h on the 1974 mercury 500 50hp. The prop has some nice sized dings outta it, but other than that, is that a normal speed for full blast? Also went through about 20 liters of gas in about and hour of run time. Is that normal? I try and adjust the bottom cab but doenst seem to make any defferance in how it idles. Let me know, thanks.

 

[verado7]

Re: Normal speed at full blast?

thats tough to say - how many people in the boat ,what rpm's are you running at wot - 20 litres an hour at wot is about right - if the bottom carb adjustment isnt making any difference you need to rebuild it ( both carbs ) .

as a comparison i have a 15.5 sangster flat bottom /deep v with an 88 classic fifty - ss prop - i get 60km/h with 1 person

 

[Jaynen]

Re: Normal speed at full blast?

Gotta fix the rpm gauge still so dont got that, but about 500lbs in the boat.

 

[Dave1027]

Re: Normal speed at full blast?

Those numbers sound about right with a dinged prop.

 

[Jaynen]

Re: Normal speed at full blast?

Cool thanks guys for the quick replys.