exhaust or burn off

[QuickMick]

after a major tune up, i got my a4 running! replacing the impeller got the cooling system under control. After dancing a jig in the cockpit, i noticed im still getting some pesky exhaust in the cabin.

how long should she need to run hot to burn off all the old crap on the engine before i start looking for a leak/gasket failure in the exhaust system? 20 min or so?

thanks
Quinn

[mitiempo]

Quinn
Regardless of the engine's condition, state of tune, etc, I don't think any exhaust should end up in the cabin. If it's smoking the smoke should exit the exhaust, not internally into the boat. Sounds like there is a leak somewhere.

[merc2dogs]

Most often, if you've had the engine opened up, you have plenty of crud. grease oil, dirt etc on the engine. It will take a while to burn it all off. A good wash down with a grease cutter followed by a thorough rinse will normally get rid of the smell (unless you've painted, which can often take a few days to completely eliminate the smell) Gasket leaks that allow oil to drip onto hot surfaces will smell the same. Key is you have to know if it is exhaust or just crud baking off, it's not always easy to tell. If it's exhaust, you aren't done yet. Ken

[QuickMick]

never thought id pray for crud.

[nereussailor]

It's a gasoline engine, so if you think that it's an exhaust leak, put a co2 detector somewhere around the motor. If it's leaking inside the boat, it will go off. If it doesn't go off it is probably just crud cooking off the motor. With a gasoline engine, I'd have a co2 detector on the boat all the time anyway.
just my 2 cents

Dave

[klem]

A CO detector will certainly let you know.

If you don't have one, start up the engine and look into the engine compartment right away. It takes a few minutes for the engine components to get warm enough to burn off any crud so if it happens right away, there is a good chance that it is an exhaust leak. Another thing is a well tuned ear can hear an exhaust leak.

Having an exhaust leak is a serious safety issue so be careful when you are troubleshooting. Keep all your hatches open and try to have a friend be there but standing in the cockpit where they can see you but won't get fumed out. The trouble with combustion gases is that you never notice that there is a problem which is the reason you want your friend standing somewhere else so they can see when you get loopy. Also, if you get lucky this friend might even have a good nose and ear.