Mmmmmmm, food for thought here!
No dumb moments.... (well apart from buying 2 stroke!). £43 for 255 miles is what I paid. My main re-fill was at the fuel barge up the Medina in Cowes. I bought 139 litres at 24 pence per litre. The rest, all about 30 pence per litre, I got in cans from my local canal marina. The twin 60hp two strokes I had on my old Ribcraft 5.85 used almost £1 per mile. A round trip to Cherbourg last year cost me £140. That's why I got the diesel! Even if/when red diesel goes, it’ll still be half the cost I was paying!
Firstly, let me correct my last post when I said that full blast would 'reduce' the litres per hour.... I obviously meant 'increase' it. ie.... it would use more fuel per hour... (sorry, double negative brain storm there!). Anyway, it's interesting that you used 100 litres, (presuming you were full to start), for your 135 miles trip. That works out (100/135) to .74 litres per mile... which is not far from the .69 I reckoned I used (@ 13 knots average)! I wonder how long it took you? If you were doing 21 knots from start to finish it would have been 6.4 hours... which means you used 15.6 litres per hour. Rather more than mine at 13 knots. I'm not sure where this number crunching is getting us but it's fascinating non the less!
As far as prop is concerned, I've currently got a 23" Ally.... I WANT a 21" s/s. Most other people I speak to think I should be able to get 35 knots with no problem even with a full tank!
OK, maybe I DON'T need a 21" s/s!? 2hp isn't going to do a lot is it? I do wonder if the engine will produce enough extra power to get to maximum revs anyway, when it's loosened up a bit?! I think I will have to borrow a few props next year to see what difference they make! Most people I've talked to though do say a s/s is best with this engine and 23" may be a bit course. Until I try some, I will remain 'confused of Iver'.
Thanks for the thoughts!