Briggs 8.0 Genpower (Generac) smokes when hot

[citytransplant]

We lose power occasionally. Sometimes twice a year, sometimes not at all. Usually power is restored in minutes. Sometimes hours. During major ice storms or similar disasters, we have gone days without power.

I have a portable generator powered by a B&S 8.0 gas engine that I have used on a handful of occasions since buying used 10 years ago. I fire it up 2 or 3x per year if I need to or not. I pulled her out yesterday and she started up fine. After the engine warmed to operating temp, a flap (protective cover?) next to the muffler began smoking. I immediately shut the unit off and watched it continue to smoke until it cooled. I waited a while before restarting, thinking maybe I was mistaken and the smoke (blueish) was coming from the muffler and not the flap. Sure enough when I restarted and she got hot, it was clear that the smoke was coming from the carburetor side of the flap (see photo).

Today I took her outside and started her up and looked closely at the carb side of the flap as the engine was running. After running for about a minute, a fluid that looked like oil began to accumulate on the flap (carb side). It appeared as if it were being "sprayed" or "spit" on. Then when the muffler got to temperature (hot), the substance began to smoke. At that point, I feared the flap would catch fire, igniting the plastic fuel tank above, then .... KABOOM.

Any guess as to what's happening? Could it be oil? If yes, where is it coming from and what is the fix? Thanks.

 

[mrmikey]

Overfilled?. Mine would run for 5 minutes or so and then puke oil out and smoke like the devil. I finally realized the oil level was checked with the dipstick in all the way not just on top of the fitting. Instructions, who need 'em LOL.....Mike

 

[Bird]

Probably no connection, but what oil are you using in it? Way back in 1973, I bought a little Winnebago that had a 2.5 kw single cylinder Onan generator. And it wasn't long until its exhaust got to smoking bad, so I took it to an Onan repair place and when I went back to get it, in the heat of the summer, they said it had been running for 24 hours and no smoke. They asked what kind of oil I'd had in it. Same as in my car. But that's when I learned that engines that run that hot need an oil that's rated for diesels. Never had another minutes trouble with that little generator.

 

[Egon]

Time to wipe it down real good. Find out where all the gasket joints are and really clean them up. See if there is a breather line from the crankcase/valve rocker area to the carb manifold. Then start it up and watch. Hopefully you will be able to see where it's coming from. I would assume it has not run long enough to be able to tell if the crankcase oil level drops.

 

[citytransplant]

I forgot I began this thread until I signed in today (after being away for a few months) and searched most recent posts. Thanks for your replies. Bird, I'm unsure what grade oil is being used, even though I'm the one who changed it (he says sheepishly). I will keep your experience in mind however as I proceed. mrmikey I will re-check the oil level, keeping your experience in mind. Egon, thanks for the advice. I'll get a bunch of rags, clean 'er up and take a closer look.

I will report back at some point in the future.