Why are the spark plugs in my lawnmower covered in black after two minutes?
Ax asked:
I have a Weed Eater push mower with a Briggs and Straton engine.
I have a Briggs and Straton engine. Once the plugs are covered in black dust. I lose power and it inevitably shuts off.
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I have a Weed Eater push mower with a Briggs and Straton engine.
I have a Briggs and Straton engine. Once the plugs are covered in black dust. I lose power and it inevitably shuts off.
October 17th, 2009 at 3:47 am
oil i think dougie fresh
October 19th, 2009 at 5:40 pm
possible oil leak or possible bad connection wiring problem Tony R
October 21st, 2009 at 10:01 pm
The black soot (dust) is pretty common on any spark plug. That’s from the burning fuel. Now the reason it loses power and shuts off is something that needs to be looked at by a mechanic. My best guess would be that the air/fuel ratio is not right. Refer to the owners manual on air/fuel ratio setting miracle man
October 23rd, 2009 at 11:59 am
maybe your spark plug is African American? inkie
October 23rd, 2009 at 2:27 pm
The float in your carburator may be sticking. Does it seem to run better going uphill versus downhill? James L
October 26th, 2009 at 4:21 pm
u need to be a bit more exact really, it sounds like carbon contamination,
is your plug the exact one, it may be running too hot a plug, ie, the plug dissapates the heat too quickly and lets the carbon build up,
this assumes it is a 4 stroke engine,(as most B&S engines are)
if it is a 2stroke it will more likely be a fueling/mixture problem, ie, not enough air/too much oil in the mix cuchullain
October 28th, 2009 at 4:26 am
Find a flat tipped screwdriver.
Unscrew the air filter housing screw (top center)
Tilt out the cover and remove the square filter.
If it’s REALY dirty, or covered with oil, go buy a new one. #491588-S
They usualy get oil on them from tilting the mower to clean under the deck.
If per chance you have a 4.5hp briggs with the foam filter, the carburator base is made of plastic, and is held in place to the fuel tank with 4 phillips head screws.
The carburator diaphragms between the carb. and tank are notorious for slipping and causing the engine to run rich.
(engine numbers would have been helpfull) Mr. KnowItAll
October 29th, 2009 at 8:07 am
to rich of a mixture to much gas not enough air it is either a really dirty air filter or the choke is on all the time run it without the air filter and see if it runs better site23
November 1st, 2009 at 8:49 am
sounds like a dirty air filter clean with water and let dry fully if a foam filter if a paper filter replace big dave
November 4th, 2009 at 2:48 am
Black is not normal……. normal is a dry TAN color…… black and dry, rich, black and oily…… oil.
Now if black…… (it could have a classic style engine or quantum) so I’d recommend just replacing the air filter… If its foam, clean it with soap and water, sqeeze it good, let it dry a day and oil it and sqeeze the oil throughout, and out. It more then likely has no carb adjustments,….. the most at all being a idle mixture adjustment. 572ci.