Chainsaw Repair

Hi Al, my latest Mac is a little used 650. Runs good has ~150 comp. Damn thing won't oil. The diaphragm looks OK and is not ruptured and I can force oil to the bar port with air pressure and manually it now oils a bit..... You reference problems with these things too. I have a number of Macs and this is my first oil pump problem.Should I just replace the diaphragm? It looks fine other than a witness / stretch mark from the plunger. I might just switch out one from another saw but.......Ed
Current inventory:
1 Pro Mac 805
2 Pro Mac 700
3 Pro Mac 650
1 Pro Mac 610
4 Homelite XL / Super XL12  a couple small Stihls etc. Wife not pleased.They are all runners though!

Why you keep putting this here. I moved your last post to it's own thread. Pro Mac 650. http://chainsawrepair.createaforum.com/mcculloch/pro-mac-650/  Will move this too once you read it.