What makes a lawnmower engine try to run backwards? I prime the carburetor, give the rope a tug, and the engine about rips my arm off. What is going on?
An out of time engine can "kickback" drastically at times and the painful result is not fun. Fortunately, there are a couple things to check for to insure the timing is correct. You will have to remove the top engine cover and inspect the slot in the top of the crankshaft. You may also have to remove the starter cup and its nut to view it. The slot in the crank should be aligned with the inside slot in the flywheel, and they should be held together by a small aluminum key in between them. If your mower has come to an abrupt stop lately while running at speed, the key may have "sheared" or broken if you will and need to be replaced. That is what it is designed to do. A very cheap part, and not hard to replace either. The other timing scenario to be quite concerned with is the OHV valve adjustment. I presume this 24HP is an OHV engine. These engines have a built in compression release that operates at low engine speed and then cancels when the engine is up and running, whether pull start, or electric start, they incorporate that feature. If the valves need adjusting (and they do periodically), then timing is a little off and kickback can occur. Briggs has several charts and instructions regarding the setting of the adjustable valves in an engine with OHV. Check on these 2 items and your kickback problem should be resolved.
May 15, 2011 |
Craftsman 24 Hp 48" Deck Yard Tractor