List Need advice. My Model 15/5411 Universal is ailing. Several months ago had the exhaust manifold replaced after replacing several freeze plugs (water leak). Soon thereafter the exhaust pipe riser developed a hole and as a result the engine compartment was flooded with exhaust smoke/carbon. The exhaust pipe riser was replaced. Soon thereafter I started smelling exhaust fumes. Bottom line. Mechanic has diagnosed the problem as piston ring failure caused by the engine ingesting the carbon exhaust/carbon. Due to the ring failure I have "blow by", that is, exhaust gases are blown into the crank case and exit the engine via the breather tube, which causes exhaust gases in the cabin. the smell that I have noticed. I am faced with an engine overhaul and some big time boat units. Rings need to be replaced and any other problems caused by the carbon build-up needs to be corrected, i.e. cylinder walls, bearings, etc. Does anyone have any experience with this problem? Any observations and/or suggestions would be appreciated. John Jennings
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