To truly dissolve carbon requires a very strong chemical solution, conventional spray cleaners (like carb clean) will not do it. Consider what it takes to clean an old oven! It takes something akin to pain stripper!
MMO and BG products are truly insufficient for hard carbon, regardless of what the u tube videos say.
Short of mechanical removal, What works is liquid paint stripper (like aircraft paint stripper) or similar products that contain Methylene Chloride. Examples include a pail of Berryman's CHEM-DIP carburetor cleaner (the kind where you submerge the carb overnight) and liquid paint gun cleaner (the kind where you submerge the paint gun overnight) . Note the pattern here, and all of the chemicals will immediately burn your skin.
You can, if you are very careful, use thin versions of these chemicals in a functional engine. Piston at BDC, oil drain plug removed, add just enough to cover the piston, monitor as it drains through, add more as necessary. Do this for a full day. Remove any excess, flush the oil pan with Kerosene and perform multiple oil changes afterwards. Even then, there is no guarantee that the chemical won't cause other issues. It will dissolve carbon on the piston ring lands and crown without damaging metal. There is high risk of damage to the head gasket. So make sure not to get it anywhere near the gasket.
It is a good idea to keep the quantity used to a minimum by ensuring the piston is level and add just enough to get to the rings. The thin stuff will flow through. The thick stuff will not. Takes 12-24 hours to work, and must remain wet with fresh solvent.
At this point, you may not have much to lose. The engine will not fix itself and more viscous oil is just a crutch. I'd guess you either have a broken ring, or a carboned up and stuck ring (more likely)
MMO and BG products are truly insufficient for hard carbon, regardless of what the u tube videos say.
Short of mechanical removal, What works is liquid paint stripper (like aircraft paint stripper) or similar products that contain Methylene Chloride. Examples include a pail of Berryman's CHEM-DIP carburetor cleaner (the kind where you submerge the carb overnight) and liquid paint gun cleaner (the kind where you submerge the paint gun overnight) . Note the pattern here, and all of the chemicals will immediately burn your skin.
You can, if you are very careful, use thin versions of these chemicals in a functional engine. Piston at BDC, oil drain plug removed, add just enough to cover the piston, monitor as it drains through, add more as necessary. Do this for a full day. Remove any excess, flush the oil pan with Kerosene and perform multiple oil changes afterwards. Even then, there is no guarantee that the chemical won't cause other issues. It will dissolve carbon on the piston ring lands and crown without damaging metal. There is high risk of damage to the head gasket. So make sure not to get it anywhere near the gasket.
It is a good idea to keep the quantity used to a minimum by ensuring the piston is level and add just enough to get to the rings. The thin stuff will flow through. The thick stuff will not. Takes 12-24 hours to work, and must remain wet with fresh solvent.
At this point, you may not have much to lose. The engine will not fix itself and more viscous oil is just a crutch. I'd guess you either have a broken ring, or a carboned up and stuck ring (more likely)
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