Pre engine pull, winterization

nola mike

nola mike

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So unfortunately have had personal issues that have kept me from the boat over the last month, and I won't likely have a ton of time before next season to devote to fun stuff...
That said, I had planned to pull the engine to fix an oil leak, replace the steering cable, clean the engine/bilge, etc.
I've had an a/f gauge which more or less stopped working for most of the summer. Eventually started working again, but was reading lean (upper 14's) across all rpms. Prior was very rich (12s) at low speed and richer (11s) at WOT. Nothing changed (looked for an intake leak, vacuum looks ok, idle speed unchanged). Pulled the plugs (below, 2 plugs looked like the close up pics).
Compression on a cold engine was 148-150 on 5 cylinders and 137 on #5. No matter how many times I checked 😉
Didn't change with oil in the cylinder. No time for a leak down test.
Not great but probably nothing I need to do anything about ATM.

IMG_20241117_123351.jpgIMG_20241117_123324.jpgIMG_20241117_123306.jpgIMG_20241117_123216.jpgIMG_20241117_123142.jpg
 
Scott Danforth

Scott Danforth

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Valve leak if oil doesn't change the numbers

Drain the water jacket, pull the motor, oil the ports and cylinders, and kick it under the bench for winter
 
Scott06

Scott06

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nola mike said:
So unfortunately have had personal issues that have kept me from the boat over the last month, and I won't likely have a ton of time before next season to devote to fun stuff...
That said, I had planned to pull the engine to fix an oil leak, replace the steering cable, clean the engine/bilge, etc.
I've had an a/f gauge which more or less stopped working for most of the summer. Eventually started working again, but was reading lean (upper 14's) across all rpms. Prior was very rich (12s) at low speed and richer (11s) at WOT. Nothing changed (looked for an intake leak, vacuum looks ok, idle speed unchanged). Pulled the plugs (below, 2 plugs looked like the close up pics).
Compression on a cold engine was 148-150 on 5 cylinders and 137 on #5. No matter how many times I checked 😉
Didn't change with oil in the cylinder. No time for a leak down test.
Not great but probably nothing I need to do anything about ATM.

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by the look of the plugs suspect you are still rich and the o2 sensor may be on its way out. I don't think they like being in wet exhaust long term, even in the dry part of it...
 
nola mike

nola mike

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Scott06 said:
by the look of the plugs suspect you are still rich and the o2 sensor may be on its way out. I don't think they like being in wet exhaust long term, even in the dry part of it...
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Agreed on that (although with the engine off it reads 14.7). Whaddya think about the close up pics?
 
Scott06

Scott06

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nola mike said:
Agreed on that (although with the engine off it reads 14.7). Whaddya think about the close up pics?
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thats what made me think you are still on the rich side not lean. the full circle of color on the base of the threads means it is not lean. Mine get a bit brown on the insulator too.

Is there corrosion on there too?

Also think you are fine on the compression for what we are doing ...
 
nola mike

nola mike

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Nope no corrosion, was wondering about the metallic stuff on the electrodes. Otherwise they look a bit rich but not terrible.
 
Scott Danforth

Scott Danforth

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you store your boat on a lift about 20 feet from shore. could just be salt air and condensation in the combustion chambers

could be a bit of reversion at idle coming into the lift because the 4.3 is on the raged edge of reversion

cold be you have a leaky issue.
 
Scott06

Scott06

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nola mike said:
Nope no corrosion, was wondering about the metallic stuff on the electrodes. Otherwise they look a bit rich but not terrible.
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I was having trouble making that out would defer to SD. As long as it is not aluminum from detonation I think you are fine.

Be careful- as long as the engine is out Danforth will have some sort of stroker or something over 500 cubes going back in...
 
Lou C

Lou C

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Ok when I had leaky head gaskets that put a bit of water into #2 cyl and just a trace in #1, I did have spark plugs with that orange cast to them, and there was a bit of rust on the electrodes. However, the only way to tell for sure I think is an oil analysis, if salt water is getting in a few cyls, you likely will have sodium in the oil analysis. That was starting with my engine even before the HGs blew, for a couple of seasons, and I had high levels of sodium in oil analyses I did in 2011, and 2015 with sodium being at about 230 ppm each time (the overheat happened in 2013 but the HGs probably started leaking before that because it was elevated in 2011). After the top end overhaul the sodium level dropped to about 20 ppm with the last one done in '23 showing 16 ppm. So depending how deep you want to delve into this, it might be a good idea to do an oil analysis. Even some people will question the usefulness of them, I think it's worth it, you then establish a baseline and can follow changes, and find things like this. On closed cooled and auto and truck engines, you can find antifreeze getting into the oil before it destroys bearings. In fact the people at Blackstone Labs refer to antifreeze (glycol) as the silent killer!
 
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