Re: motor position
Got it. I see the pitch so, so much for that. I also see that you can't hang the engine off the transom, so much for that. I guess we are stuck with raising your engine. Your bracket doesn't seem to have a way to adjust it. CMC or something like that is an after market supplier and I have followed some threads on here where people use their jack plates. The JP is adjustable and you can jack it up as high as necessary to solve your problem. I think they are around a couple hundred bucks. They may sell them on here.
Like Philster said, you may need to get up 3" to get where you want to be. On the prop pitch, if it handles your boat well when up and running then just concentrate on the jack plate.
Mark
I just www'd and found "CMC Jack Plates" easily; not sold on this site. They are 2 piece, easily adjustable with a wrench up to 5". Perfect.
This edit is the next morning from this original answer. Some bad news as I see it so far.
I stuck "1.6 Liter OMC Sea Drive" into my Google search engine and came up with some interesting replies. Before the site cops throw me in jail, I loaded the same question in this site and got nothing for an answer....lots of answers but none dealing with the subject....so in your grace, please forgive the following:
I played with some of the replies and picked up a few pointers but the real "meat" was at another site titled "thehulltruth"....leaving the prefex and suffix off and let you add it. There was a lot of pictures and a lot of jabber about them and numerous usage and changeover senario's . Suggest you go over there and get some ideas.
In short, I doubt the conventional jack plate will work for you. The Sea Drive is an integrated unit (to my learning) and doesn't look to be easily adaptable to a jack plate....but if you can figure out how to add it, I'd go for it.
One guy did draw a picture of what Philster said in his initial response to you that the engine is begging to be lifted. Looking at the cartoon the guy drew he showed how the water came up behind the boat and any engine placed back there (off the transom) had to be higher mounted or it would be too deep and offer poor performance....hence the "raise her up". He was talking about shallow water operation, but what we are talking about applies too.
Here's the kicker you won't like. Some of the boats that are laid out/configured/setup whatever, like yours in even 18' have a 2.5 liter sea drive not the 1.6 you have. That compares favorably to my estimation of your HP being around 85-100 hp and theirs 175-200. That goes along with what I said about in my opinion, with your rig and all the stuff at the transom, your engine is too small to fight the load of getting on plane. Granted those engines weigh 600# to your 300 or so, but they have the power to brute force their way through it.
I wish I could be of more help, but without being there and rubbing elbows with you to solve this this is about the best I can do.
Good Luck,
Mark