The Forestry Forum

well not a chainsaw but a 2 stroke problem and I think you folks can help me. I have a dolmar back pack blower it runs fine for about 5 miinutes then slowly loses power and stalls, about 7 years old and has alway run flawlessly, any ideas. thanks ahead of time glenn...

Change the gas filter. Possibly a gas tank vent issue

Glen  As ken said vent or fuel filter, to check the vent , after it stops loosen the cap and listen for air going in the tank. Tighten the cap again and try starting it. If it runs good for 5 minutes again you have a clogged vent. I don't think it would run 5 min with a clogged filter. but wouldn't hurt to check it.  It could also be a bad coil, check how good the spark is after it dies. Check fuel lines for cracks also.  Good luck.  Steve

I have been doing some thinking and here is what I have come up with about this anomoly. The rings are more than likely worn. As the saw is cool, you have enough compression to get it running. As the engine heats up and the worn rings loose compression, ther-by causing your problem. Can you get a compression tester?This will tell me if I am wrong or not. However 7 years for a blower  IMHO is pushing it. God luck, Ken