680 Haines soft top 225yammy solas prop ,trip approx 120klm averageconditions 1.2lts per klm we run at around4700rpmaverage 29knots. 1.https://itunes.apple.com/au/app/dail...36978041?mt=83 lts per Kim
Hopefully it is as simple as your fuel gauge being unreliable, which would be nothing unusual. As someone has indicated, just reset your odometer each trip and make sure you fill the tank, it will only take a few typical trips to get a better feel for it. Once you have done that a few times you won't need to rely on the gauge as much.
Edit: what speeds are you getting for those RPM?
680 Haines soft top 225yammy solas prop ,trip approx 120klm averageconditions 1.2lts per klm we run at around4700rpmaverage 29knots. 1.https://itunes.apple.com/au/app/dail...36978041?mt=83 lts per Kim
What make of hydrofoil are you using. I tried a couple on my victory. One in particular, a SE Sport, created a massive amount of drag to the point it did affect the economy and would have required a lower pitch prop - RPM dropped by about 400. The other one, a Permatrim, wasn't as bad but still created drag. Eventually I took it off as well and fitted trim tabs. It might be worth removing the foil for a quick trial to see if it is making a difference.
I have a week at 1770 for the M&G. I'll use the foil for the first over nighter. Then on the second one I'll remove it and compare fuel used. I'm unsure of the make as it came with the rig and there are no identifying marks on it. Tabs are another story. Cause of my duck boards it makes it harder. Also I'd have to move my tranny, and I'm quite happy where it is. haha
MAybe take the tranny out and you will have 1 less POB henceforth better fuel efficiency.
Gee I have been surprised by the fuel figures quoted, I would have thought DI and 4 strokes would have been way better figures. Not knocking anyone but it makes buying a new motor something further down the list than I had thought.
Haines 620SF, 175 oceanpro bluesmoke, to Barwon banks and back with a bit of running around, 83 ltrs at the servo.
GPS indicated 39.8km to destination at Mooloolaba bar.
I generally sit on 3500-3800= 26 ish kts.
I spose thats about 1km/ltr. I am happy with that.
They are actual figures, not guesses, I could be maybe, 5 ltrs out either way.
Still, I'll put the purchase of a 4 stroke or DI on the backburner methinks, for + .8k/ltr isn't worth the investment in my books.
I know there is a guy with the same hull at the sunny coast with a 175 zuke, if he said barwon banks for 20 ltrs, I may change my mind, but really, big boats use fuel, I can live with that, its way better than the 25 Berty with 165's I used to own. Either way, it's about having fun.
Dean