On Wednesday, March 18, 2020 at 8:44:07 AM UTC-4, Cgray1521 wrote:
replying to Jon, Cgray1521 wrote:
Im trying to get my grandparents yard boss running but having the same
issue. Hard to pull at first, feels like because of compression, then releases
and spins over. Ive torn everything down twice. This last time I noticed
the gap on the spark plug was closed. So I looked at the piston and it has a
slight surface rust mark that matches the shape of the bottom of the side
electrode on the spark plug.
So I feel the piston is just slightly hitting the spark plug. Thought maybe
someone over tighten the spark plugs so I bought a new one. But the new does
the same thing. If I install the spark plug by hand as thought as I can it
will run fine. But if I put a wrench on it and tighten it literally a hair
more it locks up. DONT GET IT!

--
for full context, visit https://www.homeownershub.com/mainte...ll-824350-.htm


I know this thread is old.
Did anyone ever find a solution?
I have older 025c, which is rarely used (but I run it dry when I do use it).
I can barely pull the starter cord. If I remove the spark plug, can pull with one finger. Removing the muffler does not help. Removing the chain/bar did not help.
No obvious scars on the piston/rings.
I put a some oil on the piston/rings, no difference.
I'm at a loss.