I recently picked up a few 029's that were not running. On the first saw, it was obvious it needed a new fuel line, but everything else looked good. No I did not do a pressure/vac test yet. It was in such good condition and ran somewhat when I got it so it appeared to be an easy fix. Anyway, I put a new fuel line and filter on it last night, and the saw fired right up and seemed to run and idle good. However, I could not get the saw to 4 stroke when trying to tune the carb. I put it down and went to work on something else. After it cooled, I tried to start it again, and it fired up on the first pull. However, it still would not 4 stroke. And this time, when revving it up, it would also bog at higher RPMs. So my question is, besides a leak test, what do these symptoms most likely mean? I was thinking since the fuel line was in such bad condition, it's possible the impulse line isn't much better, maybe it is sucking air? Carb rebuild needed? Also, I did pull the muffler back off to check for any scoring, and it was perfect thankfully. Any ideas?