Stihl Blower runs fine but rpm slows after 30sec

[soikel]

Hi folks,

I have a BG50 that starts and runs just fine for about 30 sec, then it slows down to about half speed. It still runs smoothly, just low rpm. I ran it without the spark arrestor but problem the same. Hopefully some ideas out there.

 

[bertsmobile1]

TAke the muffler off and see if hat makes a difference .
NOTE it will be very loud
After that try swapping the fuel filter .

 

[Fish]

While it is running, remove the air filter and see how it runs.