Help Repowering Boat

[HookedOnMarsh]

Well the reason I'm getting rid of this powerhead is I can't figure out exactly what is wrong with her, but I think the exhaust plate or bottom crankshaft seal is leaking water in the #5 cylinder. It is only a little amount of water; shows up on the plug as a water droplet after shutting down the engine on the garden hose. Cylinder is not cleaned out looking and the plug otherwise looks normal except the small water droplets on it. My block has seen so much saltwater that the thought of turning any bolts on it is a nightmare, and we know how many bolts go around the exhaust cover. I dread just pulling the powerhead off after what I went through with the removing of the lower unit and the right cylinder head.

I still have around 100psi compression, all even within a couple psi. The stator low speed windings burnt out due to a bad idle/advance module. I have replaced the stator and removed the module. Only electronics on it now is the switchboxes and the rectifier. I have advanced the WOT timing up from factory 19 to 24 at WOT to compensate for the missing advance module. I am only getting 5200-5400RPM out of it and is hard to start sometimes. If you hit the gas after startup it just sputters and then clears out and runs. Now it likes for you to ease it up on plane and then WOT. When it's running high speed it never misses a beat. Startup idle is horrible and smokes out the place sometimes and sometimes not so bad. I'm going to try removing the oil injection and premixing somewhere between 50:1 and 75:1 and see if the smoking at idle goes away.

Another thing I notice is once I get it moving everything seems fine and takes off fine. Just seems very cold natured acting until its ready. Could all this be because I don't have that idle/advance module? I hate to throw another powerhead on it and it do the same thing all because this little black box went bad and it can't adjust the timing as needed to keep the motor running in gear after starting it? I understand you can't even get these black boxes anymore because they failed so often? Where could I possibly get a good one? I don't care so much that I lost the few degrees advance but the low speed idle advance would really help out my problem.

But in the long run, I think I would be best served getting rid of this block and getting something else. I want a motor that can get this boat out to the blue water and back without problems. 50 miles out is not uncommon. My friends say they would feel very safe in my rig that far out, but not with that motor. My buddy, CB on the last trip out was talking and petting the 'sweet girl' when she didn't want to start the last time. Really was funny to watch him do that, but rather not have to see us do that again.

[macojoe]

I have the 1985 175 hp that BS speaks of, Its on my 23' Sea Ox and it gets up and goes awesome!! I get 2 1/2 to 3 miles a gallon and this boat is one heavy ba2tard!!
I have always hayed Merc's but this one is great!!

[HookedOnMarsh]

I guess it's just my luck that this happened to me. Motor ran great when I first got it and man it had unbelievable power. It would launch that big tub and would have to pull the throttle back just a hair to keep from going over 6000RPM. Now full throttle and only 5200-5400. My top speed has also dropped from low 40's to around 35MPH. Was nice while it lasted though!