To help us understand, what are you describing as a weak spark?

Sometimes, a spark may be almost invisible. Position the spark plug wire about 5/16 inch away from the cylinder head (use duct tape to hold it). A dark area such as a closed garage is a good place to perform this test. A nice pull on the starter usually results in about 500rpm. If the ignition system can deliver a spark with this test, the ignition system should be good.

Check to make sure the air gap is set correctly between the flywheel and ignition coil. Without a model and serial number I canÂt say for sure what the correct gap is, but it is normally around .010"-.012". Also make sure the coil is installed in the right direction, some have an arrow on the coil showing the direction of engine rotation.

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