No spark replaced coil an spark plug still no spark. On ryobi backpack blower. What else would cause no spark. I'm thinking kill switch. How would I check that. Thanks

check switch is bad if not coil bad if not getting spark

sounds like your kill/shut off switch is bad grounding it out. Unhook the small wire from the coil and see if you have spark then, if you do then the problem is the switch or safety switch and or possibly the wires that run to the switch .

PROBLEM Engine fails to start. CAUSE - REMEDY No fuel in tank - Fill tank. Spark plug shorted or fouled - Replace spark plug. Spark plug is broken. (cracked porcelain or electrodes broken) - Replace spark plug. Ignition lead wire shorted, broken, or disconnected from spark plug - Replace lead wire or attach to spark plug. Ignition inoperative - Contact authorized service center.

I am guessing you have checked the normal things spark plug HT lead on/off switch clean fuel Just a small hint the spark plug that the machine comes with is rubbish so if you havent please replace it and make shore the gap is correct

I assume you mean it has no spark, if that is the case, did you check via the spark plug or the spark plug wire. Either way, it can be one of these three things;

1). Spark plug is broken or severly fouled.

2). The kill switch is leaving the circuit open. Test the kill switch for continuity/discontinuity.

3). The ignition coil has become faulty.

Be sure you have no spark ( 90% of the units that come into my shop for repair with the complaint of no spark- have a fuel issue). Be sure the spark plug is good.
If no spark then remove the ground wire from the module and check for spark again. You must use the recoil starter- spinning by hand is not sufficient. If still no spark then replace module. If there is spark with the ground wire disconnected then there is a problem with the kill switch or a bad wire.

disconnect coil kill wire and isolate from engine side kill switches, if fire returns then coil is good, if not then coil is bad and must be replaced

1) Make sure the kill switch is off, or in the position to start

2) It might be a problem with the kill switch, try replacing that first.

3) Use new and clean fuel mixture

If the engine is sticky ie harder to pull it might have to be pulled apart new piston and honing of cylinder. not difficult just a pain. If it doesn't seem any harder to pull, Drain all of the unmixed fuel. Put a few drops of 2cylinder oil in the spark plug hole and pull the starter a few times with the plug out of it. Put a few more drops in repeat. Replace the plug (new plug) Put in mixed fuel prime the system cross your fingers and it should start up for you.

check the kill switch and all your wiring make sure there are no shorts also are you sure the coil is gapped right?