Mower starts perfectly, but seems to rev up and down

Hi my mower (Honda) has a problem. It starts perfectly and seems to run perfectly for the first minute, then starts to rev up and down. It doesn't stall but seems like it wants to. I checked and replaced the spark plug, and I also checked the air filter. So both are new and this problem is still happening. Also, this past winter I left gas in the engine over the winter. In the spring I emptied the gas and refilled it with fresh stuff.

Any ideas? Gas flow? Carburator?

Thanks

Smash

Well Smash, it appears the carb. is a bit ill, best solution is to remove and thoroughly clean the fuel tank, replace the fuel-lines, filter, and shut-off valve is so equipped, THEN, a super cleaning of your carburetor, that's the best way to insure you have no problems with the fuel system. Always drain the tank, and run the engine out of fuel, before storing for long periods.

Boobala said:

Well Smash, it appears the carb. is a bit ill, best solution is to remove and thoroughly clean the fuel tank, replace the fuel-lines, filter, and shut-off valve is so equipped, THEN, a super cleaning of your carburetor, that's the best way to insure you have no problems with the fuel system. Always drain the tank, and run the engine out of fuel, before storing for long periods.

Click to expand...

Thank you, I appreciate the help!