Pulled out the Mantis tiller this fall and it was acting like the pump diaphragm was giving up. This didn't surprise me as it's 10 yrs old so I figured it was time for a new carb. I gave up trying to kit these little carbs!! Added about an ounce of seafoam to the full tank and finished what I was doing. Two weeks later started it up again today for another project and it starts easier and no surging like it was doing before.