Sthil FS 38 backfires

[fjr6470@sbcglobal.net]

Had my Stihl FS 38 in storage for two years. No gas in tank but some in primer bowl. Added gas and no start up. Thought carb was the issue. Replace carb with OEM Zamba. Tried to start and it began to back fire ( exhaust port and intake port) . Checked coil and tested good. Installed new Stihil Oem coil and the backfires continued and it did not run. Did not look into the shear pin as it ran perfectly before it was stored. Any ideas as were to probe next.

 

[ILENGINE]

Make sure the exhaust port isn't been clogged with the remains of critters or carbon buildup. A plugged exhaust will cause backpressure and popping out the intake.

 

[StarTech]

Also make sure you installed the correct ignition coil. It and the crankshaft timing were changed back in 2001.