QuestionI have a Craftsman 4.5 hp (about 9yrs old). When trying to start, I sometimes get a very quick and forceful kick back on the starter cord. I have several hand injuries to validate this problem. Help,please.
Ken
AnswerHi Ken
I suspect a partially sheared flywheel key, caused by hitting an object with the blades or by a loose blade. Check it and replace it, by following my proceedure shown below:
Good Luck,
Michael
The flywheel is located under the recoil/cooling shroud. Its' bore is tapered and mates with the tapered crankshaft. The keyway in the flywheel and shaft
keeps it from spinning on the shaft. A nut secures it. Use an impact wrench on the nut or a strap on the flywheel. Don't put force on the cooling fins or they will break. The recommended way to remove a flywheel is to use a puller. An alternative, is to tap on the crankshaft top, with a brass hammer or use a punch tip on an air
hammer. The flywheel will need to be held up and supported or upward pressure applied with 2 large prybars. (A 2 person job.) Care is needed so the flywheel doesn't crack or bend. Also be careful to not mushroom over
the crankshaft top. Replace the key. Install the flywheel after cleaning the tapers and re-tighten the nut to 65 ft/lbs.
There is also the possibility of a bent or twisted crankshaft depending on the severity of the impact but usually the key just shears.
