After the machine has been running for about 45

Hi Lawrence.
There should be a few more numbers/ letters to your model number. I added a link to a website for you to check out. Click the link or copy and paste it. Hope this helps.

https://www.repairclinic.com/Shop-For-Parts/a22b303d782009/Model-42A7072653E1-Briggs-Stratton-Small-Engine-Parts

This website should be able to help: www.briggsandstratton.com

I have a Craftsman Snow Blower with a Briggs & Stratton Engine. I had the same problem. I searched online and read a little bit about this run and stop problem. One solution was to put something over a piece of metal that separates the hot engine part from the other part of the other side of the engine. I used a piece of heat resistant cloth from Lowes in the plumping area where the torches are. It fit and worked. Engine keeps running. I ran it for over an hour last spring prior to storing it.

Incorrect valve tappet clearances, this will stop the auto deco valve in the engine working.

replace air filter, check throttle linkage position, take to a pro shop and have governer adjustment checked

probably ignition coil.common problem

I also have this same engine and am also looking for the owners/workshop manual . Also went to Briggs & Stratton with no satisfaction. If you find anything please drop me an email aswell. Thank you. [email protected]

No such thing exists - but you can get an Operator's Manual for the engine if it's a Briggs & Stratton, direct fron the Briggs web site.

sounds like the needle and seat is dirty within the carb