Poulan 295 problem

[Wildbullmustang26]

I’ve got my dads poulan 295 on the bench and I’ve got it started and running and Idling smooth. But when I started to do some test cuts the saw idle becomes very fast with the chain break off almost to a full rev and won’t come back down to a slow idle. Any ideas on what this could be? It does it every time, I will shut it off and let it sit and it starts and idles just fine then after 1-2 cuts it revs up and won’t come back down.

 

[Maintenance supervisor]

Its sucking air in some where?
Could be crank seals or a hole in the fuel line.
Don't run it or it'll smoke the top end.

 

[Wildbullmustang26]

Its sucking air in some where?
Could be crank seals or a hole in the fuel line.
Don't run it or it'll smoke the top end.

I was thinking the crank seals as well from what I have read.