Suggestions:
1. Pull the muffler, check for carbon buildup/restriction. If it runs for minutes w/o slowing, this is probably not the issue. Ck cyl and rings for good surfaces while the muffler is off.
2. Check the compression cold, and then check it hot to see if the compression is affected.
3. Tweak the fuel mixture toward rich to see if itâÂÂs starving for fuel.
4. With an inline spark tester check the fire to see if it is maintained. Ck the points.
5. Good Fire/Fuel/Compression is needed for the combustion engine to run AND Exhaust!
6. Double ck the carb that all ports are open Good with wire or compressed carb cleaner.
7. That old, could it have a swollen rubber seat in the carb causing it to starve for fuel?
8. Will a prime restart it as soon as you give more fuel? Again, try to Detect Fire/Fuel/Compression.

The engine will run really good for 2 or 3 minutes, I did not time. The compression is very high, can only pull through one firing cycle when starting, the same after hot, no compression release. I tried to make the mixture richer with the low speed adjustment when the saw started running poorly but It did not help. After the engine dies you can restart it but it runs poorly. How do I check #6? Do I remove the adjustment screws and squirt carb cleaner?
This saw was given to me by my great uncle.

1. Depending on what you did in the carb rebuild, I would suggest the following to verify all ports are open.
2. I would suggest disassembling the carb, rem all rubber non metal Etc and soaking the carb 8 hrs in carb cleaner (with mixture screws removed).
3. Run wire, compressed carb cleaner or compressed air in all ports to verify they are opened.
4. If the saw sat with fuel in it years and untreated, it could be some stubborn varnish or debris in the carb.