Push Lawnmower - No Spark - 3.5 HP Briggs & Stratton?
I was given a 20 year old "Rally" push mower with a standard 3.5 hp Briggs&Stratton engine. A bowl type carburetor and pretty simple and straight forward overall. The housing and all looked pretty good, but it didn't run. I changed oil, new air filter, new spark plug, rebuilt the carb, sharpened and balanced the blade, and filled it with fresh gasoline. However, I got no spark. So I installed a new magneto (which is today's substitute for the old fashioned coil and points of course) and a new magneto ground wire. Still no spark ! All was installed as the directions indicated including the gap for the magneto against the magnets. What the heck ! What's left ??? I double checked for all the average "stupid" errors, but don't have a clue why I still don't get a spark. Aside from the magneto, the secured wiring and the new spark plug... what else takes part in generating a spark that I'm not presently getting? Boy, I sure feel like an idiot at this point !
Not really sure if it is the problem or not.
Keep in mind continuity from coil legs to block mounting posts is for completion of electrical circuit, required for any electrical circuit to exist. Grounding the internals with the kill wire is something different as it is short circuiting the deal as it is shorting or grounding the supply from the coil to the plug. The coil legs are simply allowing the plug to return juice to the coil to complete the circuit.
Showing continuity from the kill terminal to coil legs is the same as to the block and is completing circuit as well, just not the operating circuit.
If you have good continuity from coil legs to block and have the kill wire disconnected and get no spark, your coil is dead. Providing this is not a old point ignition unit.
Good luck!
