I have a Honda engine on my push mower, when I start it up, it runs good, then about two minutes later it begins to miss out, loose power, then backfire thru the carburetor once and die. Most of the time it wont start back up, let it set a while, and it will start back up but after a few minutes, it does exactly the same thing again. I have already cleaned the plug, fresh gas, cleaned air filter... This mower is only 3 years old, and only used about 3 hours a week. I only have a couple of accounts that I need it for, everything else I can use the bigger mowers on. Any ideas would be greatly appreciated, thanks!