Small Engines (Lawn Mowers, etc.): Stihl FS90 Hard to Start, half tank, coil ignition

Question
I have a 20 year old Stihl FS90. When I can get it to start, it will run for about half a tank, and then it will bog down and die. Forget about restarting for the day. I have used fresh gas 50/1 mix, stihl/dolmar brand. I am buying the repair manual (ebay) I suppose I should replace all hoses, and get a carb rebuild kit. Should I be checking any thing else? Compression is mentioned alot in your threads.  

Answer
Hello Michael:

You Say it Runs Out a Half Tank and then Quits. You Can't Restart Until Next day. Check the Plug for Fire when this Happens. Usually this is an Indiction of a Bad Coil/Ignition Module. If there is Fire at the Plug, then Check the Compression. No Less than 80psi Cold. I'm Thinking the Coil/Ignition Module. If the Rings were Sticking or Worn Out, it Would Not Run for a Half Tank. Usually About 5 Minutes is Max if the Rings are the Cause of this Problem. Hope this Helps. I am Here if You Require More Assistance. Let Me Know What Happens, Please. Thanks.

Good Luck

Respectfully  

John