At my wits end again….

[chevysford]

I posted awhile ago about this tower of power that has been giving me a lot of trouble and the journey. Fast forward to now and I have brought the boat to a mechanic and he didn’t even look at it after having it almost 2 months. So I found a cheap boat with a mariner 115 on it and I robbed the parts I needed for mine which I assumed was my carbs. Swapped all three and some other miscellaneous parts I was missing and voila- she ran even better! Reved easy on muffs and I thought I finally had her. I then brought her down to the water and the same thing happened that happened before. I took off from the ramp and she died about a half mile from it. Wouldn’t start back up, acted like she wasn’t getting fuel again. After about 20 minutes of floating, I adjusted the idle cable way up and was able to get her running back to shore extremely slow. I got her to a pier and started messing with air fuel mixture screws. Set them to where the engine actually responded again and went back out from the launch. Ran ok, seemed a little slow, made a turn and she started bogging down again so I limped her back to the pier. Something’s I noticed this time that are different: 1. The exhaust ports near the pea hole have a lot of water and smoke spraying from them. 2. When I rev her up high I’d hear a weird noise and smoke appeared to back through the sparkplug wires to the top cdi.or the smoke was from under the cdi somewhere. Other things I did: I changed the water jacket gasket and stopped the leak I had coming from the sparkplugs. Please help

 

[Chris1956]

Gee, not sure what to say.
1. Those exhaust ports just under the powerhead are for idle relief. It is normal for water to come out of them, when motor is in neutral, in the water. I doubt that is an issue,

2. Revving an old motor up not under load, exposes any piston slap or bearing play. At this point with that motors age, it doesn't tell you anything.

Not sure where smoke is coming from. Transfer covers are under the CDI boxes. Maybe they leak?

Smoke should not come out of cylinder head, as it is one piece with the block. It cannot leak unless block is cracked.

Your engine wiring looks real suspect with that 1/2 roll of electrical tape (picture #3) on it. Are you sure the wires are in good shape, clean and connections are tight?

Your carbs look like they were submerged as do other parts of the engine. I assume salt water use? Anyway, they are likely most of your problem.

Remove them, strip 'em down, clean 'em up and install new gaskets, inlet needles and seats and floats.

It makes sense to do a link and synch on that motor, to make sure the timing is correct. Screw up the timing and the engine can be severely damaged.

Set idle mixture to 1-1/2 turns open, and adjust them on the water, engine warm with fresh 50::1 fuel.

The idle mixture needs to be rich enough to allow for acceleration yet lean enough to allow good idle quality. If the engine bogs under acceleration, the idle mixture is likely too lean. Richen them 1/8 turn, starting at the top carb and working down, one carb at a time and run a trial and error with the carbs richening them 1/8 turn and testing them after each adjustment. it will take a 15 min - 1/2 hour to get them dialed in well enough.