mower revs going up and down

[slybunda]

Any product i can get to put in fuel that can clean up the carb?

 

[tshephard]

I have been babying one of these for years.
As someone here already mentioned, there is a wear item, a diaphragm that needs replacing.
I suspect engine vacuum pulses create a fuel pump, but I know replacement fixes things.
Lowes or HD have 'em - $5

 

[JavierH19]

your old engine is having throttle dysfunction. needs to take in supplements now to make it go up and keep it there.

 

[Supersonic]

Check the air filter too. I put the Star Tron in my gas can for about 2 gallons and that has kept it good and I never cleaned a carburetor since.
http://www.starbrite.com/item/star-tron-gasoline-additive