My lawn tractor engine started hunting badly (revving, cutting out, revving etc) during the last cut. Its never done this before. If I pull the choke out a bit it smooths the problem, I've changed filters checked fuel lines, pump and vacuum tube, all appear to be good. Any help would be welcomed.

JT, April 2009

First, drain the float bowl, as a blob of water can cause this problem, Next, check fuel pump delivery. It should pump with vacuum pulses applied (by mouth) to the vacuum connection. If OK, suspect fuel cut-off solenoid (screwed into bottom of float bowl).

After that, you will have to strip the carb to check for a blocked jet.

phil_saunders(a)bigfoot.com

Phil Saunders, April 2009