Originally Posted by jyasaki
Twin 70's will yield the equivalent of a single of about 100 maybe 110 hp, so you should be fine in that regard. Watch the max engine weight (if they have it listed), and you should be fine.
I have not found any info on max weight. Typical 115 four stroke is around 400 lbs. This setup will be at 514 lbs.
I also have access to a single 115 Yamaha Tuna Special (E 115 AETL), those are the old style 2 stroke carburated simple engines found on tuna speed boats. It weighs around 338 lbs. They are not sold in most developed countries due to the emissions.
I love 2 strokes but the range with a 25 galon tank on the 115 Tuna Special will not be as good as with the twin 4 strokes. Also, I can avoid the premix and listen to some music while I cruise.
The 115 Tuna's are bullet proof, they start them dry as they launch the speedboats running to match the main vessel's speed. They drop them in freefall too!
I'm at a point where I need to make a decision soon. Any experecience with any of these engines or any other input is apprecieted.
Basically its 115 2 stroke + kicker (carburated, no DI) vs twin 70 4 strokes ... redundancy is key as their is no Sea Tow or other rescue service in our waters ...