Ryan99 0 #1 Posted October 30, 2017 I have GT1600 that starts fine when cold but after running a couple minutes it will not start. It cranks over fine and has spark. I've tried starting fluid and it won't even try to fire. I'm looking for any suggestions as my son loves it and uses it to pull the lawn sweeper. Share this post Link to post Share on other sites
gwest_ca-(File Mod) 10,444 #2 Posted October 30, 2017 Welcome to the forum. First thing I would do is try a new pair of spark plugs designed for this engine and properly gap the electrodes. Spark plugs can fire out of the engine but fail when in the engine under compression. Spark plug gap is critical in magneto ignition systems. Too small a gap results in weak spark. Too wide a gap can compromise the insulation on/in the ignition coil because it will release that energy somewhere if it can not fire the plug. If new plugs don't make it run remove them and save for the next time Garry 2 Share this post Link to post Share on other sites
SylvanLakeWH 23,808 #3 Posted October 30, 2017 Does it stall out when it gets hot? Is it getting gas at carb? Thinking maybe starved for fuel? Vent cap plugged on gas tank? 2 Share this post Link to post Share on other sites
Achto 26,199 #4 Posted October 30, 2017 Fellow Cheese head. Both suggestions above sound like good places to start. 1 Share this post Link to post Share on other sites
aHorseofCourse 261 #5 Posted October 30, 2017 Magnito is bad. The Briggs twins go through them. Once they get old they get weak and it's worse once they get warm for some reason. Should be able to find one on the bay. 1 Share this post Link to post Share on other sites
Ryan99 0 #6 Posted October 31, 2017 Thank guys. No it does not stall when running. It runs really well. When trying to start it has plenty of fuel. I just replaced the plugs a year ago. I'll order a magnito and try that. Someone had told me the valves might worn and not closing fully. Has anyone seen that? Share this post Link to post Share on other sites
Fordiesel69 188 #7 Posted October 31, 2017 If you used champion plugs at home depot or lowers with the pin point electrodes, that is your problem. Order the correct ones from a dealer and make sure they are plain. None of that marketing crapola. Our 16HP and 18HP both had that issue and I found it was the plugs. I also could be the mag as others suggested, but try plugs first, their cheap. 1 Share this post Link to post Share on other sites
aHorseofCourse 261 #8 Posted October 31, 2017 (edited) 7 hours ago, Ryan99 said: Someone had told me the valves might worn and not closing fully. Has anyone seen that? I think you are referring to the valve seat issue these engines had. The seat would come out of the block and not allow the valve to close. Highly unlikely this is your problem here. It would still run on the other cylinder and the problem would be constant, not just when warm. Valves could just be out of adjustment but I don't think that would vary with temperature either. Edited October 31, 2017 by aHorseofCourse 1 Share this post Link to post Share on other sites