Universal m-18 engine smoking

Jan 19, 2019
15
Catalina 27 Vancouver
Just took my Catalina 27 (with a universal m-18 motor in it) our for a cruise. It noticed a slight running sound when I started it up, went cruising for 20 mins and opened the engine compartment and a bunch of smoke was in there. I can’t see any belts rubbing or anything touching the engine that is melted. It smells like electrical or rubber type thing. I came back to the dock and killed the motor to have a look. Started it up again and running at full throttle tied to the dock and can smell it slightly but not as bad as before. Been running it for 20 mins now at the dock . Water pump has good flow. Any ideas ?
 
Jan 19, 2019
15
Catalina 27 Vancouver
Now I notice that when I put throttle up all the way, it will only go up to 2000 rpm. My typical cruising is 2200 rpm and if I wanted to I could get it up to 3000 rpm usually. Something with the fuel maybe? But not sure how that would have caused the engine to smoke
 

Kopite

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Mar 11, 2015
107
Catalina 27 Monroe MI
Is your alternator belt adjusted properly ? The tach is driven by the alternator, and the belt may be slipping, giving an incorrect tach reading and possibly the smoke..
 
Jan 27, 2008
3,010
ODay 35 Beaufort, NC
Check your exhaust system. The insulating wrap on the pipes can hide a lot of corrosion and possibly a hole or crack. Also you likely have rubber exhaust hose before and after your water lift muffler. Smoke in the engine compartment is bad, an exhaust leak is a carbon monoxide hazard, a deadly possibility. Your water injection elbow could be constricted with carbon build up or corrosion restricting the flow of exhaust gas and thus the engines ability to function properly. Check that too.