I took my lawn tractor out for the last mow of the season, and wouldn't
you know it? After about three minutes, it stalled suddenly and spewed
out a big cloud of blue/gray smoke. I pushed it back around to the
garage, looked around the engine for anything unusual and decided to
try it again. (This all took about ten minutes, and therefore it
probably cooled a little bit). It started, but ran kind of rough, and I
think there was slightly more smoke than usual. Then, again after about
2 minutes, it suddenly stalled again with a cloud of smoke. The engine
is a 5 yr old Briggs and Stratton, model 287707. I went to check/change
the oil, and over 1/2 gallon of oil/gas mix (mostly gas) came out.
Somehow the gas is leaking into the oil reservior. What has happened?
What do I need to check?
Your float is stuck, rebuild the carb and flush out the gas by having 2
oil changes, dont run it it is now lubbed by gas, take out the plug and
crank it likely its full of gas too. if you still want to mow keep the
gas shutoff till you are ready to run it, but change the oil, run it 1
minute and change it again. Stop after a few minutes to see if oil level
is going up, if it is just stop for the year. It should only happen ,
the flooding, when the motor is stopped, but running with diluted oil
will kill a motor.
Since the engine has already run five minutes and stopped twice from lack of
lubrication with all the gasoline in the crankcase, much much more damage
has already occurred than would be possible from any possible residual
gasoline in the oil after changing it. Sure can't hurt to change it twice
though. A fuel cutoff is the only preventative, even the electric cutoffs on
the carburetor are subject to leakage.
Be absolutely sure that the plug wire cannot spark against anything
while you are cranking it. This happened to me last spring. If there
is gas in the cylinder it comes out in a fine spray. One spark and you
would have a flame thrower. After the oil change, etc., I installed a
gas line shutoff valve. They are cheap.
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.