I bought a 290 second hand, I currently have as much in it as a new one, I thought $150 was a good deal( Wrong ) I have a new bar, chain,and breather on it and the carb just got rebuilt. When I used it yesterday it bogged down real bad in big wood, does great one 12" and smaller, get into 18 and up it will get half way through and the chain will stop, not slip, but stop, back it off and it will go some more and stop. Is a 20" bar too big! The saw shop said no. I am used to Husky's, I hope this isn't normal for Stihl's. Any help would be appreciated. Thanks,Jon