Yep filled from the bottom, after letting it drain overnight. removed and cleaned out the reservoir. It is a 1995 MPI. Smells very rich. I am fine with upper 60's for now. Just want it to start and shift and be reliable lol.

Got a tester at work (0-100psi ok?) Not sure what you mean by cool or VST . The engine serial number is OF533769. Regulator is in the back I think, yay I get to pull the engine cover again( kinda sucks doing it by yourself). I will try to remember to bring home that gauge today. Big problem is I have no way to run it out of the water. I found those "muffs" to be worthless and cost me a brand new impeller on my other boat (330hp bravo 1 ). I rigged up a valve so I could hook a hose directly to the intake line and shut off the drive pick up. Great for winterizing it too. May have to order parts to do this one. Would love to hear about how any of you guys run your boats out of the water.

OF593772 is the engine serial number whoops. The hatch is electric, but when open, it blocks access to the regulator and distributor(thats why I had to pull it when I did the tune up). Wish there was a definitive way to tell if headers are leaking without pulling them off the engine/boat. I heard the lobe separation angle is small on marine cams to prevent reversion, so once it is running water is not likely entering. But if I marked the balancer and pulled the plugs out of the cylinders that had open exhaust valves after shut down, maybe?

Remove the Outputwaterhose from Header and close this side, and build somesthing to give pressure on the input side!
When there is a hole in the header,the pressure will allways gone!
Michael

I think my headers may be different, than ones you speak of, but maybe I could remove the straight pipe and cap the collector?

I got the pressure tester, and a buddy coming over to help remove the cover. So, what am I testing?

could have a dead cylinder..you mentioned that one plug was missing an electrode? I would start with a compression and spark test and co from there...may have a bad head gasket causing low compression...once you get the running issues sorted out I would move back to the drive issue...I'm betting that is a bad intermediate shift cable...shifting them with the engine off can stretch those...I would also look at the shift cavity for evidence of water which could be a sign of the back cover leaking...this will cause the detent ball to rust a seize...mine had similar issues shifting when I got it and it ended up being that whoever put the drive on last didn't hook up the shift cable correctly to the drive and just crammed it on causing it to get stuck in gear....but like I said I would start with the engine issues first...one problem at a time...that thing should start just like a modern car and sit there and idle.

Well, lake season is over here, winterized the boat. Had 6 ppl, fuel and beer and trimmed out at 65mph(GPS). This may not sound too impressive, but I am super excited for next year. Since muffs have never worked for me, I had to go at winterizing by draining everything. Since I was all wadded up in there any way, I did a compression test as suggested. All summer I always crossed my fingers everytime I shut it off, hoping it would start again. Some super stressful moments, but she always busted off eventually.
135-141 on cylinders 1-6. 7 was dead, yep 0psi, and 8 struggled to get 10psi. I am thinking leaking headers and 2 bent rods. Least I made it till off season. Question is where are the headers leaking? is it possible it is just at the collector gaskets/seals ? They were leaking black sooty water all over the engine and cover/hood when I first bought it. I tightened the clamps and is stopped spitting water everywhere, but there was still sooty residue after every outing. I want to run headers, I dont want to bend anymore rods. I hate to plop down cash on new headers if new gaskets is all I need. I know nothing of these marine headers, I have read a bunch on the forums about how hated they seem to be- and understandably so. If any one knows how to tell where a leak is, please let me know. Also would love to hear suggestions on a rebuild, any special components needed? I have heard about cams, and something about rings and head gaskets. is this stuff absolutely necessary? If the engine has a roller cam, can I put a cam for a 525 in its place? I want to stick with a marine grind for sure. Also thinking of losing 100lbs, and going with aluminum heads- any down side there? All of the plugs were sooted rich, so there is definitely a problem with the fuel system as well. Since I know nothing about this MPI setup, I am thinking of shelving it, till I can afford a procharger and figure how to tune it some day. May go with a good intake and a huge spreadbore Holley. Noticed they sell "marine" intakes as well, anyone no why I couldn't run an automotive version that's 200 bucks cheaper? Obviously the excitement is not from the cubic dollars I am gonna be forced to spend, but from seeing the results 2 more contributing cylinders are gonna net.

Post a pic of what headers you have. You are going to need to pull the engine. Pressure test the headers with them removed from engine.
I doubt you have bent rods. No way it would keep running without blowing up. More likely to have holes in pistons or valves burned or stuck.