By your model number thats a Pro Mac 700 saw, not a bad saw, i have a couple MC saws kicking around here to. My Stihl is my go to guy but the little MC's are awesome for quick limbing and firewood trimming, etc.
It uses a 3/8" pitch chain. I usually like to replace the chain and the bar at the same time when i get a used saw, no telling how it was taken care of. I put an Oregon Pro Lite 16" bar and chain on my Pro Mac, got it from the local Menards. They come as a complete set, swap and forget!
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1984 Honda ATC200ES "Big Red"
1982 ATC200E "Hondie"
1988 TRX300FW "Project Quad" Still in progress....