Jac Posted July 14, 2006 Posted July 14, 2006 Have a 3314 that starts right up and runs good for about 20 minutes or so. It then begins to backfire, and then stalls, and can't be restarted until it cools down. There is a fuel filter that shows that it is getting fuel(the filter is full of gas). Can anyone point me in the right direction? Thanks Jack
HubbardRA Posted July 14, 2006 Posted July 14, 2006 Jack, We had a similar problem with my oldest son's Landlord, just last weekend. It ended up being a manifold gasket. It would seal when the engine was cold. As the engine warmed up it would start leaking and create the symptoms that you are having. I adjusted the carb, and it ran a while longer, then did the same thing again. We were lucky, we could see a little bit of fuel seepage along the gasket. You can also check these gaskets when the engine is running by spraying starter fluid or carb cleaner around the gasket. If there is a leak, it will suck in the vapors and speed up significantly. No leak, no change in engine.
Jac Posted July 15, 2006 Author Posted July 15, 2006 Rod, Checked for leaks like you suggested, and found everything ok.Re-adjusted carb and ran ok in garage. Hopefully the rain will stop and I can get it out in the yard. Is it possible that the valves are not seating properly when hot? I just got this tractor, and I don't know when the head was removed to clean things up. jack
HubbardRA Posted July 15, 2006 Posted July 15, 2006 Jack, after years of operation, the valve can beat the seating surface farther into the cast iron block. As this happens, the valve clearance gets smaller. As an engine warms up, the valve stem gets longer. If there is not sufficient clearance, the valve will stop sealing. Check the valve clearance, if it is significantly less than spec then that is likely to be the problem. I have fixed a couple of engines that had that problem.
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