Outdoor Power Equipment and Small Engines - Blower Shuts Off

I Have a Poulan PBV200. It was my grandfathers so I would like to get it working right. I got the blower and it worked fine. It had sat a while in his garage before I got it. I use it for work to blow out garages and decks. It probably worked good for about 2 months, then it started after about 10-15 minutes of use it would start to loose power until it shut off.

I have cleaned the air filter
replaced fuel filter
used Carb cleaner
added more oil to mixture
replaced spark plug

I have noticed that before this that the rubber spark plug had bubbled up just a little (maybe over heating ?) I know that after it shuts off I can let it sit 5 minutes and it will start or I can press the ignition bulb about 5 times and it will start back up but only run a short amount of time. Any ideas appreciated. I dont want to put a lot of money into this. So if you think I should replace it let me know a good replacement brand. Thank You
Semper Fi

First, I would make sure you are running the proper oil ratio. Adding more oil to the mix may not hurt but it's probably not a good place to start.

I would remove the carb., disassemble it and give it a good cleaning. Just spraying carb cleaner around usually does not get into the jets and smaller passages. It might have a partially clogged jet making it run lean which can cause it to overheat.

I will give that a try next week. Thank you for your time. I will do what you said and post back if it works or not. Thank you again.

Might try one last check before tearing into the carb. Start and run it until the symptoms rear up, then when it dies try loosening the fuel cap and re-trying it.
A pluged fuel vent in the cap could be all your faced with.

Also check for a clog muffler.

Jerry