Engine will not stay running

Hello,

Generally speaking, an engine will need spark, fuel, and compression to start.

Here are some guides that will help with each of these.

https://www.2carpros.com/articles/how-to-test-engine-compression

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

https://www.2carpros.com/articles/how-to-test-an-ignition-system

To figure out if it is a fuel issue, spray some starting fluid in the carburetor. Then try to start. If the engine starts and runs for a little bit, then the issue is fuel.

I you have fuel then you want to check for spark. That can be done easily by removing a plug and cranking the engine.

Let me know a few more details of what you are experiencing.
Thank you.