Chainsaw Repair

Use a BPMR7A. Mix a good oil at 40:1. Set it at 15,000 to 15,500. Keep it clean and sharp.
Want to kill it with kindness ? Mix too heavy and run too rich. It will die for sure.

As for Bosch plugs (even the German ones) at the shop they go in 2 places. 1 place is Stihl powerheads, the other is the garbage can.

Nothing against Bosch just has its place. Every new Stihl that comes from the factory with a NGK plug, the plug goes in the trash. Out with NGK in with Bosch.