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?
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 ) .
Pull the muffler and take a look inside. Tell us what you find.
#4
Fish
Also take off the starter and take a peek, a loose screw could be jammed somewhere.
#5
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.
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?
Won’t find evidence until you tear it apart. If you think it is a bent rod, you better figure out why. Personally I’ve never encountered a bent rod in a small engine.
#13
Fish
A guy on arboristsite bent a rod on his ms170 by improperly trying to remove the clutch or flywheel.
#14
Fish
Here are 2 of his projects, both trying to remove the clutch or flywheel.
#15
Hammermechanicman
I have removed probably a hundred clutches and flywheels. I never use a piston stop unless i have to. I use an impact and a hammer and have never bent or broken anything. I wonder what the guy was doing to bend it like that.
That’s certainly not caused by force of a normally running engine, more like someone who doesn’t know what they are doing. Probably using a breaker bar with a four foot pipe extension. Surprise he didn’t rip the threads off first, unless he was turning it the wrong way.
#17
StarTech
I had this year that the piston stop busted the piston crown here on a chainsaw but it was because someone had over torque the clutch using an impact. And Hammer there are times that you must use a piston stop along with a pull bar on the backpack blower to get the fan off.
But I never seen a bent connecting rod until now. I thinking that tech was trying to loosen a left hand threaded clutch the wrong direction.
#18
Fish
Yeah, You have to use a piston stop and hand wrench on those big fanwheels.
But on the bent rod one, he filled the cylinder all of the way with rope, and put an angled force on the rod.
