How does a lawnmower act if the flywheel key is broken?
Answers:
'zardoz' said what i would of said. Good answer I will vote for him/her.
Other answers:
it won't run at all if its broken...if slightly damaged it will run roughly and die shortly afterwards.
it won't run at all if its broken...if slightly damaged it will run roughly and die shortly afterwards.
IT WONT RUN
The shear key keeps the engine in time so the spark-plug will fire when it's suppose to. It's function is to protect the engine if you hit something with the blade.
If it's sheared just a little it will cause the engine to run rough because it will be just alittle bit out of time. the easiest way I've found to remove the flywheel is to first spay the shaft with a nut loosener,if you don't have this you can also use a small amount of oil. next use a screwdriver to pry up under the flywheel at the thickest part, usually where the magnets are.use just enough tension to put some strain on the flywheel.put the nut back on the end of the shaft, so that it's flush with the end. while prying up with the screwdriver rap the end of the shaft with a rubber or plastic mallet. DO NOT FORCE IT. take your time working around the flywheel hitting the shaft, it should come loose. It's a tapered shaft and hole in the flywheel so it will be a very snug fit. when you do get it off check to make shure that the key-way isn't worn, if it is there isn't much you can do. the key's are very soft so take care when you put the new one in.
good luck & happy mowing
Sounds like you have something in the carburetor. I had same problem last spring. Mower would start, run about two seconds and die. Then I would prime it again, and same thing. had to have carburetor cleaned out. good luck.
Sounds like knifeboys on it. On the bottom of your carb should be a round part; take it off and see if the float is stuck. Unstick it with some carb cleaner and your hands. Put it back together and try to start it.
Good luck
Zardoz has it right with the key.... btw, get your flywheel nut torque settings... check the engine manufacturers website first, they may have it...... I know briggs does.... if its not down to the torque it needs, you'll shear the new one... pb blaster is a good rusty nut buster (napa sells it 4.49 a can) flywheel keys are cheap, big pack of em for a couple bucks.... one thing to do, make sure the keyway on the crank, and the flywheel are clean, no oil or nothing.... this will shear the new key... if this doesn't do you, Usually when I check for a fuel problem, little ether/starting fluid or gas down the carb, if she fires... carb needs a rebuild..... doesn't? then I go through spark, compression, and flywheel key. This is if it backfires alot, it could be slightly off timing..... but it does indeed sound like a clogged main jet in the carb, OR fuel supply isn't good.