I noticed today oil on my Merc 25 prop. It is black and not the color of L/U fluid. What is causing this? A broken seal or is it residue from my exhaust?
2-stroke or 4-stroke? If it’s a 2-stroke, it’s likely just oil residue from your exhaust, especially if your engine has only been run at idle speed lately. Remove the drain plug from the L/U to see if the gear lube is milky. If it’s clean, run your motor hard and see if it continues to show up. Mine had a bad case of it last week because it had not been run hard for several trips. I only ran short, slow trips in the creek and on the flush muffs in the driveway.
carbon build up mixed with exhaust
motor may be running rich at idle
do a carbon treatment
what is a carbon treatment?
- I’d rather be a free man in my grave than living as a puppet or a slave.