I have a Dayton 3Z678B--same chassis as the White 1855 or MTD995. I used it to till my garden earlier this spring, and also to mow a half acre pasture earlier this spring.
Yesterday I hooked up my 3 point aerator attachment to aerate a friends lawn about 1/4 mile from me. The tractor started fine and ran fine for 20 minutes or so, but then the engine started hunting like it was fuel starved--pulling out the choke a little helped, but it got worse... to the point that it stalled.
I was able to drive it back to my yard--at an idle, and the choke all the way out, though it stalled a couple times in the process.
It's powered with a B&S 420 series 18 hp twin.
I pulled the top off the carb and there was very little fuel in the bowl..but no sediment or deposits, either. The engine was also very hot--the intake manifolds so much that I couldn't put my hands on them without getting burned.
I noticed that when I inverted the top of the carb, the brass float wasn't level per the specs-- it would be too low and not let enough fuel in, so I bent the tab to level it out. While it was off, I used carb cleaner to blow through the various ports including the fuel inlet and the high speed jet port--though no deposits of any kind were found.
I reinstalled the carb and adjusted the high speed jet a little richer.
Started it up and let her run--ran fine in the shade of the big ash tree in my yard, but when I started working her out in the sun, same problem.
The fuel line isn't restricted, and has a plastic shroud-- like those used for electrical wires, over it to protect it from the heat of the engine.
I think the fuel is vaporizing in the carb as the engine heats up, thus creating a low fuel situation. I'm thinking it may help if I remove the side panels, but does anyone else have any suggestions as how to cure the problem??
Thanks in advance,