piston issue?

[babss]

my bg56c piston won't rotate beyond bdc unless i spin the flywheel in the opposite direction where it stops at bdc again. i put a new carb on because gas in the muffler and difficulty pulling the rope without wrist injury. is it worth fixing?

 

[bertsmobile1]

Probably not for a BG56 but it will only cast a bit of silicon to pull it apart
Most likely some thing has fallen down the induction tube
The bottom ends are generally a crowded race so don't give you grief
The other reason would be lumps of a broken piston.
Farmer Teck do replacement barrels & pistons for a reasonable price .
I have fitted a lot of them to various engines with good results when you get the right one ( can be a problem ) .

 

[Rivets]

Pull the muffler and take a look inside. Tell us what you find.

 

[Fish]

Also take off the starter and take a peek, a loose screw could be jammed somewhere.

 

[Hammermechanicman]

Nothing to lose, try this. Remove spark plug and turn unit upside down and rotate flywheel back and forth a dozen or so times and see if the problem goes away. If there is liquid fuel in the crankcase you can get the problem you describe and it hydrolocks.

 

[babss]

the bottom of the piston is contacting the counterweights on the crankshaft. with the piston removed, I can grab the connecting rod and everything rotates smoothly. wtf?

 

[Hammermechanicman]

Bent connecting rod.

 

[StarTech]

Or needle bearing failure.

 

[Rivets]

Star hit it on the head, bearing or bushing failure. Most likely cause, unless you replaced any internal parts.

 

[babss]

Or needle bearing failure.

no evidence of that