Hi Jim.
What sold me on the F-115, was (at the time) not only its fuel injection, but the fact its internally-beefed-up, from it smaller brothers with essentially the same block. It is also considerably heavier, the report I read I believe was “Powerboat Magazine” I wish I would have saved it! From its weight-advantage, I would say that the internal “beefing” is quite substantial!
From her fifth season now up in the “far north”: when I checked the valve-clearance @ 1300 hours (a year or so ago); there was ZERO out of tolerance! That right there, was rather awesome in itself! I have worked the crap out of the big Yami, even though I do take the best care possible of it by frequent (twice a year) oil&filter changes, and running Mobile 1 fully synthetic the last 3 years.
Yes I did install it myself; it was really easy, considering I have that rack on the transom! I went off it with a heavy-duty ratcheting strap, to elevate. There was no need to reposition the holes either, it bolted right into the old holes from the 3 previous two-stroke motors. I like the added-weight a bunch! Matter-a-fact, it ain’t enough! I also like a heavy kicker, plus whatever weight I carry in that rack over the transom. Probably because I have them huge trim tabs, and carry a crapload in the cockpit too….. gawd ya think a fella would just get bigger boat! LOL
Also: I had no trouble at all getting insurance from State Farm. My old Classic is rated for a 90 max. So I’m 25 hp over that. They said that was completely acceptable, long as it was not “way over powered”. Any yes, the power and torque are to die for!! There is no better engine out there for the 22 C-D. :thup :note