Carb jets on newer vs. older carbs

[Jacob J.]

One more question for the experienced saw guys here; I took apart a number of Walbro carbs from 044, 064, and 066 saws today. The newer 066 carbs with the plastic adjustment screw covers had either #62, #64, or #72 on the "fixed" jet. My question is, can a person slightly enlarge these "fixed" valve jets?

 

[rupedoggy]

I am probably over my head here but my brother, sawracr can help if I am and KD if he can't, but I never had trouble getting enough fuel to my saws. The problem is getting enough atmosphere!. I bore out the carbs and then just back out the high speed and have always had enough fuel to make them run. Why does it help to put a bigger hole in the jet? I could understand if one is trying to get it to run on alky but there always seems to be enought gas. Mike