No combustion on bottom cylinder

Hi all my name is Mike and I have a 81 lund guide special with a 35hp johnson. I've had the boat since 1996, grandpa left to to me. The motor has ran like a watch up until last fall. I was trolling and it started puttering. I'm not getting combustion on bottom cylinder. Opened it up had water in bottom cylinder so checked head warpage and replace head gasket. Replaced thermostat as well. Compression was mid 120s before I did gasket and after new gasket. New plugs, tested plug wires, coils, power pack, sensor coil and charge coil as are spot on. Carb has been taken off cleaned and new needle valve. Gas in line and carb look fine. But motor still runs same. It putters at idle and bogs if I give I throttle like it's only running on one cylinder. My next and only thing I can think of is fuel pump. I read somewhere that a bad fuel could possibly flood bottom cylinder. Top plug looks perfect but bottom plug looks fouled and wet. Any other ideas would be tremendously appreciated. Thanks, this forum is a great resource and always better to have extra eyes, ears, and minds to help people figure out problems. Thanks again.

What is the model number of that engine?

Are you still getting water in the cylinder(s)?

You're getting 120 psi compression on both cylinders right now?

With the s/plugs removed, the spark should jump a air gap of 7/16" with a strong blue lightning like flame... a real SNAP! Does it? NOTE... The 7/16" air gap is important! Spark testers are available at any auto parts store.

Pull pump apart.----It may need a new $5.00 diaphragm for fuel pump.-----Water could be getting in from exhaust cover gaskets or bottom crankshaft seal.

Model# J35ELCND. I have 126 on top and 124 on bottom. I dont know if there is water in bottom cylinder right now, is there a way to check that with out pulling head off? I picked a spark tester yesterday and had trouble getting any spark with it, going to make sure my ground is good and try it again after work. I can get a snappy spark if I just hold the plug 1/4-1/2" away from engine block. The exhaust gasket sounds like could be something. I though the amount of water spitting out of the breathers in back was a little much but never paid attention to it when motor was running good. Also there is something like a joint about half way down the motor shaft that I noticed water coming out of, again I never paid that close attention to these areas before when the motor ran fine. So spark test, fuel pump check and exhaust gasket are next in line then for me, thanks a bunch guys. Any other thoughts or comments feel free and I'll reply back with an update.

Fact for you.----All outboard cylinder heads are warped when you take them off.----It is the nature of aluminum casting that have not been stress reiieved when new !----So did you refinish / flatten the head ?

Ok thanks. I checked the head with straight edge and the center portion, in between cylinders was the low spot, did a couple quick rounds with sand paper spray glued to a piece of glass. Used a marker and sanded until it disappeared, checked depth gauge as I went, took off about .01-.012 off. I forgot this head was worked once before when the water pump went out about 15years ago so my clearance now is pretty tight to say the least. A smidge of a nick piston on head without gasket. My old gasket was .045 so I figured my new gasket that was .065 was going to crush down to that same .045" thickness, which I think leaves me enough room for heat expansion. Motor compression should be a touch higher now too.

If water is present in the cylinder, it'll be present on the spark plug. No need to remove the cylinder head,

Checking spark... remove spark plugs and set them aside. Using spark plug to test spark is a waste of time.

Have you ever checked the spark with the spark tester set at 7/16" ??

So it has a history of water pump failure? If it overheated, it is reasonable to think the exhaust cover gasket is the culprit causing water intrusion. If true, it will destroy the powerhead if not dealt with.

I will be replacing the inner exhaust plate gasket and out exhaust cover gasket this evening. Is there anything I should pay attention to while I have this opener up?

Is this a crack in block or just a hard edge, part of the casting?

Put a light coat of permatex aviation on both sides of the exhaust cover gaskets. Look close at the inner plate for possible crack or pinhole.

Having trouble uploading pictures. That's the plan, I have a bottle of the brush on oem gasket sealer. I haven't seen anything on cure time for it though. It says it never truly hardens. Reason I ask is this weekend is my first off from work since April and my fiahing buddy from back home is out to visit so be nice to know how much time I should leave it set before I fire her up.

Overnight should be fine just snug the bolts down in a center out pattern in at least three steps. I use a 1/4 drive ratchet so i dont snap bolts or strip threads.

Torque those bolts 60 / 80 inch lbs.

Thanks for the tq numbers. So an update on the motor for those who are interested and for those who this could possibly help in the future. Once I totally get it running tops I was planning on writing a top to bottom of my experience for anyone looking for similar thing. So after I did the exhaust gaskets the motor idled like a champ, maybe better than it ever has but when I put it in gear and load on motor it did same old 1cyl putter. Did the 7/16 spark test and had nothing on top cylinder. I believe this whole thing to be an evolving situation, different things failing at different times. So replaced top coil and ran like a top for about 1 5gal tank of gas. I started to notice a little struggling/chugging in the lower-mid rpm range, guessing around 2000-2500, like the beginning of the plow stage when trying to reach plane. Realized the motor using too much fuel, estimate 1.5x of what it should be using judging from my tank gauge and normal routes I take before this whole thing happened. Plugs are pretty dark but not wet, I usually run it hard back to dock to try and clean off plugs. The 2 things that come to mind are fuel pump or maybe Reed valves? The carb has been rebuilt with new needle valve. Any thoughts