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-   -   Cyl 3 spark plug came appart. (https://www.offshoreonly.com/forums/general-q/377193-cyl-3-spark-plug-came-appart.html)

JaniH 10-04-2022 01:51 PM


Originally Posted by Cap'm Kurt (Post 4847182)

Good info, thanks alot!!

JaniH 10-04-2022 02:10 PM

Pulled the intake of today, lots of moisture below the intake. Oil in the dipstick is clear and so is the oil laying in cylinder heads, valve cover breathers are very creamy also. Could be normal taking to account that weather is cold here in this time of the year, looking at the exhaust valves, in the two center ports of both sides, the valves looks much brigther, and those ofcourse are just below the riser. I am arrraid that those cmi muflers may have related to this. I definetly have to dismantle the mufflers and check the spring tension adjustment. I try to pull the cylinder head of during this week.
https://cimg7.ibsrv.net/gimg/www.off...d50bf5479d.jpg
https://cimg9.ibsrv.net/gimg/www.off...85d8bceed1.jpg

Cap'm Kurt 10-04-2022 03:38 PM

The sludge. Probably reversion, reversion, reversion (moisture backing up in pulses thru the exhaust when idling, and yes while it is running). There's a million articles on this topic all over the internet and here on OSO. i even wrote one a couple years ago. Only way i completely solved it was to weld on 3" diameter alum extensions to the elbows( I use Eddie marine). I kept welding on 6" at a time until i reached 25". Only then did it stop alltogether. Talk about a difference. The oil looked so much better. And didn't smell as acidic. Also angle cut the tips of the 3" extensions. I'll see if i have pics. Other friends with bigger cams had to go about 5 more inches to get it to stop.

Cap'm Kurt 10-04-2022 03:44 PM

Look in your exhaust soon as you pull it out of the water. If it looks like this. Reversion.


https://cimg1.ibsrv.net/gimg/www.off...0a06779344.jpg
https://cimg2.ibsrv.net/gimg/www.off...2eeb282b9e.jpg

AllDodge 10-04-2022 03:53 PM

I went to +3 elbows on my Eddie Marine exhaust and have no issue with reversion (509 dyno 530hp), and I'm using turn downs

Cap'm Kurt 10-04-2022 04:00 PM

These resonators will stop the reversion also, but i didn't want the restriction.

https://cimg4.ibsrv.net/gimg/www.off...f294f76dc8.jpg

Cap'm Kurt 10-04-2022 04:07 PM

picture of the 3 inch aluminum exhaust extensions to prevent reversion
https://cimg6.ibsrv.net/gimg/www.off...a53ab4815b.jpg

AllDodge 10-04-2022 04:19 PM


Originally Posted by Cap'm Kurt (Post 4847304)
picture of the 3 inch aluminum exhaust extensions to prevent reversion
https://cimg6.ibsrv.net/gimg/www.off...a53ab4815b.jpg

Not to argue, but those don't look like +3 "higher" elbows, they are 3 inch long tubes that extend the water out further.

This what I was talking about. They are 3 inch higher then stock and water doesn't come out until end of tube
https://www.eddiemarine.com/shop/exh...risers-emi-552

SB 10-04-2022 08:00 PM


Originally Posted by JaniH (Post 4847285)
Pulled the intake of today, lots of moisture below the intake. Oil in the dipstick is clear and so is the oil laying in cylinder heads, valve cover breathers are very creamy also. Could be normal taking to account that weather is cold here in this time of the year, looking at the exhaust valves, in the two center ports of both sides, the valves looks much brigther, and those ofcourse are just below the riser. I am arrraid that those cmi muflers may have related to this. I definetly have to dismantle the mufflers and check the spring tension adjustment. I try to pull the cylinder head of during this week.

Maybe a head bolt or stud leaking water ? Or valve guide ? Or intake gasket ? An actual pcv can help if there are no leaks, but i suspect one..

JaniH 10-05-2022 05:01 AM


Originally Posted by SB (Post 4847321)
Maybe a head bolt or stud leaking water ? Or valve guide ? Or intake gasket ? An actual pcv can help if there are no leaks, but i suspect one..

New gen6 502 block, head bolt holes should be blind. What i did notice, is that i forgot to use any sealant in the cylinder head side of the intake gaskets around the coooling passages, but there was permatex in the intake side of the gaskets. Damn!


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