rostan wrote:Can't even expolate the data since the 210 HP version's graph goes below that but shows no SFC's.*
You could use the ratings for the 435 but what is the point? Exactly what are you trying to determine?
If you have the power curve for your prop you can use*an average*BSFC figure for your engine and calculate it. That should be close enough for short duration recreational use unless you are planning on a non-stop non-refueling round the world trip and need to calculate tankage.
The tiny amount of fuel difference will be buried in the real life performance that is altered by temperature, barometer, wind and waves, how good the helmsman,*and how the boat is trimmed. If you really want accurate data then the only way you can get that is to meter the fuel through laboratory grade instruments while collecting over-ground and through water speeds and distances to a very high accuaracy. Even then it would only tell you how you did that day and time.
Is it that important?