I went through the hanger 18mods on mine and it just never worked right. I’ve seen several others give up on them too. It was “okay” for a little while, but never optimal, and by the end not worth risking my motor. There are PLENTY of success stories out there, sounds like TT5.9 has had lots, so it is my assumption that I messed up somewhere along the way.
I offered it up to OP already, but if he doesn’t want it you’re welcome to have the 650 I modded. It has nytrophil floats, an ebay BRPV, and maybe some other parts you wouldn’t mind having for free.