fuel usage on 225 yami 4 stroke

[Mr. Sandman]

Have you got the right prop? It looks slightly under pitched to me. 4500 seems too fast for 20 Knots. 6100rpm WOT also sounds high. I don't know the numbers for 4 strokes but most big 2-strokes are in the 4500--5500 WOT. I would *think* that 4 strokes are even lower...I could be wrong for these new 4stroke outboards but it seems odd to me that they would be higher then a 2 stroke. (Generally a 4 strokes peak performance is produced at a lower rpm (producing higher torque) ...when compared to two strokes....ie: motor cycle vs auto)

I would check this out with the dealer.

(A over-reving engine could cause bearings to over heat...burning oil....just a though.)

good luck

ps.

I just read thru my service manual for my 2 stroke and it says that there is software in the computer to prevent rpms > 6100 . It starts cutting out injectors to prevent exteneded running beyond this rpm.