Scored a free JD Mower today then...

Pony_Driver

Well-known member
Joined
May 25, 2020
Member Number
1362
Messages
2,206
I pulled a JS20 out of the scrap bin at the dump today. I got it home and without touching it had it running. Someone threw a running mower out. The self propelled part didn't work but it ran. I pulled the cover and adjusted the spring on the self propelled belt adjuster and like magic it worked. I cleaned the nearly clogged air filter and it started even easier.

Later this afternoon I fired it up and ran it a bit, then my wife took over. As she was mowing I noticed sparks coming out of the muffler. When she cut it off smoke was coming up from the top center, under the engine cover. The engine is a 6.75hp Briggs. WTF is wrong with it? Stuck exhaust valve? It mows clean and pulls hard. Aside from the sparks and smoke it's perfect. 🤣
 
Is it over revving? You don't really have a baseline to compare it to but that's usually the easiest way to make a small engine breathe fire. Smoke after you shut it down is usually just something burning under the shroud, either degrease and clean or just deal with it for a while
 
and you wonder why someone junked it????

GTFO with that attitude! It's just parts. Replace or adjust the right one and it's like free money.

It is not over revving at all.
 
If it smokes like a tar kiln then your Briggs shit a head gasket. Pretty common actually. I put a new one in mine before I sold it.
 
Top Back Refresh