No spark while pulling cord slowly. Will spark if you pull the string hard(fast). The kill wire has been removed, coil armature to engine head ground is common(ok), the coil armature set to .010, no play in the crankshaft, the plug is new and gapped, the coil and flywheel are both new. Two new coils have been tried besides the original coil. Br350 stihl backpack blower about 1 year old If it is pulled real hard/fast, it will attempt to fire(sound like it), but if it is pulled slow, it does nothing
Those coils are programed to only spark when pulled above a certain rpm to prevent kicking back if pulled to slow. Problem is likely fuel related. Remove air filter and give a shot of carb cleaner down throat of carb. It should start for a few seconds. If so is fuel problem.
To start a small two stroke engine the rope needs to pulled rapidly. So from what you are saying I believe that your problem may not be in the ignition system. An engine needs three things to start and run- air, fuel and spark. Make sure that it is getting enough air by checking the filter and make sure if its a foam element that no foam has torn from the element and been sucked into the engine. Clean or replace a dirty element. Check the fuel filter and make sure that fuel can flow freely through it. Even a tiny amount of dirt can clog a filter enough to hinder flow to the carburetor. Replace the filter if it's dirty or over a season old. Clean the carburetor THOROUGHLY! Use a good quality carb cleaning spray and make sure the diaphragm isn't hardened or creased. Replace any part that's questionable. A way to test start the engine is to put a few drops of pure gasoline in the spark plug hole and quickly replace the plug and pull the cord to start it. If it starts for a moment the ignition system is good. Don't do this more than a few times cause a two stroke engine requires oil in the fuel to lubricate the rotating assembly and running straight fuel for more than a few seconds can damage the engine. Do not use starting fluid it damages two stroke engines.
SOURCE: BR340 Stihl backpack blower. Pull cord hard to
make sure unit is not flooded. some units may be hard to pull because they dont have a relief for the compression.
SOURCE: bg86c stihl blower no spark new spark plug new coil gapped right take ground wire off still nothing
Sounds like a tricky one. Have you checked the magetism/functioning of the flywheel.? Tracking back the problem by having a new spark plug and coil would next point you to the flywheel. Coil to flywheel gap should be 0.25 feeler guage.
Hope this proves useful. :)
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