Briggs and Stratton twin smoking when running

My Briggs and Stratton 12.5 opposed twin seems to let out quite alot of white smoke from the exhaust when running especially when revving. Im guessing its oil but could shot piston rings be causing it? Its a pretty old engine - 1987 i think and i doubt they've ever been replaced by previous owners.

One and the same. The rings (and especially the oil control rings) may be worn to the point of excess oil consumption. A compression test, cylinder leakdown test, and visual inspection may be in order. First off, check the oil. If overfilled, it will smoke.

Doc Sprocket wrote:

One and the same. The rings (and especially the oil control rings) may be worn to the point of excess oil consumption. A compression test, cylinder leakdown test, and visual inspection may be in order. First off, check the oil. If overfilled, it will smoke.

Thanks alot for this reply. I dont think the oil was ever overfilled and i have never done a compression test on it. I guess it will be worth a try along with a visual inspection. Any idea what the effects of not fixing this problem would be? Would it just burn off my oil?

As long as there's no physical piston/cylinder wall damage, you're pretty much OK to let it smoke. Keep a close eye on the oil level. Run it dry, and the game changes somewhat.

Doc Sprocket wrote:

As long as there's no physical piston/cylinder wall damage, you're pretty much OK to let it smoke. Keep a close eye on the oil level. Run it dry, and the game changes somewhat.

Yeah thats what i thought. I dont think theres any piston/cylinder wall damage but i'll check again. Thanks for replying.

Anytime!

my tecumseh has been smoking for atleast the last 8 years, as long as i could remember. top it off and keep a quart on all the time, keep a close eye on it, run it until it wont, then rebuild it

I'm not sure wha the air filter looks like in your engine, but you might want to check it. It may be possible to oil soak it if the engine was overfilled or tipped over while running. Oil would come out the breather and get to the Air filter, and then burn that oil for a long time. I'm not sure if that's what Doc was eluding to, but I've done it on single cylinders.

If this has been a slow progression, it's probably just the motor getting tired. A sudden change may indicate an easier fix.