Hi guys how's everyone?! It's been some time since I have posted!
I am seriously thinking of upgrading my current Toahtsu 30hp 4 stroke fuel injection (71.5kg) to a bigger Tohatsu 50Hp TLDI (93.5kg) on my Marino atom (15ft deep-V hull @ 310kg). The idea after all this is to keep the engine in the lower rpm range and hence, fingers crossed, I'll save fuel consumption and at the same time I'll have some back-up power
Also, one more thing that is keeping me frustrated is that the boat takes up to 5 persons but if I have loads of stuff (for a days fishing for lampuki/alungi or for a swim) and we are 2 or 3 people, the boat won't plane...let alone if we are 4 or 5 persons!
The engine is extremely economical when kept on the lower rpm range i.e. trolling speed (~4.5 knots) or even cruising speed (~15knots) at half to 3/4 throttle. On the other hand, when the boat is loaded and I push the throttle at 3/4 - full throttle it is a complete different story!
The boat is rated for a maximum 50hp outboard engine. Currently with my 30hp and 25L fuel tank + 2 persons, the boat reaches 22 knots at full throttle and 15-18 knots at cruising speed (3/4 throttle). This of course is when the boat has 2 persons on board and not so loaded OR else it has 3 persons and NOT loaded at all.
From my personal experience, I feel that the boat handles best up to 15 - 18 knots in calm/slightly choppy seas, of course boat handling experience and direction of the wind and waves play a very important role too
However I think that the back-up of the extra hp will not be a loss...this of course is when I need it for those times when the boat has 3+ persons or is loaded, or when the sea is calm for a fun ride, or even when there are very strong currents and the engine is struggling to plane the boat.
The majority of the times we are 2 persons on board, with tackle and stuff for coastal fishing. Also, my no.1 priority still remains fuel consumption, however after sharing my view on the topic I would like to have your opinions on the subject
P.s. I have attached a fuel consumption chart, the red rectangles (in the attachment) show 'approx. fuel consumption in L per hour' (from tohatsu website), the other two columns show 'rpm' and 'gallons per hour'.
Thanks all much appreciated!