No premix so thats all good. Yamalube  is a bit expensive 60 $ for four liters approx I reckon I use about 15 to 20 liters petrol an hour running and that seems to do a litre of oil so 30 to 40 dollars a hour approx mite be a bit lower than that on a good day. 

Been caught out on the wairarapa coast by the sneaky southerlies sitting on sea anchor too long and punched buried the thing for 10 miles with no problems. 

If there were heaps of other boats overtaking me I might think shes underpowered but havent really thought that but like you this is my first real boat, apart from zodiacs and macs. Havent had any probs with either yet, touch wood, apparently the yammy 3 cylinder 90 design is 25 years old with only cosmetic changes so it must be fairly strong, but a bit noisy, smelly and thirsty but she starts up first pop all the time. 

For my final two cents i reckon it mite come down to what your general launch spot is like, ours is a bay with heaps of rocks in it so a light motor with the ballast tanks closed and she floats in knee deep water and is easy to push around. If you have a nice concrete ramp to use upsizing would be ok. 

 

Agreed ,also somthing said for power to weight ratio - we did a very sophisticated on water test with my boat and one with a F115 from a timed standing start,same hull,he eventaully caught up and passed me but I would have been far enough ahead for my mate who was on board to start laughing in horror (he has a Yammie F150).

I can do 33kts, he could do more 36sih?,I could get out of the hole and on the plane much quicker...so I reckon your right what is safer my 90HP DI or a 115 "more powerful" wallowing 4 banger?..oh and he though I used less fuel also. 

 

I like the sound of the F100 though,that would be my pick if I was trolling/idleing alot.