I just bought a 1997 2 stroke 15hp Evinrude that is supposed to have very low hours.It runs well but the bubbles from the exhaust are pretty smokey, is it just set to rich or something else ?
Thanks
It will smoke more than normal when you first start it cold. If it still smokes really bad after it is good and warm then your mixture might be a little rich. I know that my mixture gets heavier as the season goes on because "a little too much is better than not enough" and it catches up over four months.
If you run just a little lean, and I mean like 60:1 it won't hurt it. OMC for a couple of years recommended 100:1 but went back to 50:1. You might try gapping your plugs at 40 instead of 30 if you do a lot of trolling/idling. The longer my engine idles/trolls the smokier it gets but I will take it out and open it up once in a while to blow it out. You might try running some Seafoam in your gas and doing a decarb with it. Just do a search on decarb and it will all be laid out for you. I wouldn't suggest doing it in your driveway or the neighbors will call the fire department because of the smoke.
Want to cut down on the smoke and be more environmentally friendly? Switch to Castrol Full Synthetic TC-W3 Outboard Oil. I get mine at Wal-Mart. I get way less smoke, and it's bio-degradeable. And I find that the oil sheen on the water dissipates much quicker. It will take awhile to burn all the old oil out of the exhaust housing, so give it a chance. Continue to mix it at 50:1.
in addition to all of the above suggestions, running at the proper temperature is very important. You might find that a new thermostat will help a lot with the smoke as well as with the carbon.