hcminis 1,700 #1 Posted October 29, 2012 Several months back I purchased a 753 that has a K161S 7 H.P. Kohler. Serial # 715765 Spec # 28626E. The carburetor was stuck so snagged one from rydogg...(thanks). The carburetor is from an 8 H.P. but was told should work fine. Did change the needle valves out with 7 H.P. Have put both needles valves in to correct following troubles. Rebuilt the carburetor at least 3 times now. Put a rebuild kit in the carb. Cleaned the long needle valve out with a small wire. Adjusted the carb many many times...but still runs rough. Can massage the choke some times to keep it running but never levels out. Low idle the tractor runs fine...but after 10 minutes if you try to rev it up, will choke and die. Then can't start again for at least 24 hours. Will just crank and crank...sometimes back fire and try to start but never starts. Gas will spit out the front of carb some times when starts running rough. Checked everything that I know to check. They appear fine and clean but never messed with adjusting them. The fuel pump is working fine...float is level...can adjust the needle valves up and down which changes to the running level of engine. Have put the carb in cleaner 3 times and blew it out each time. Also, has different head because original head was warped. New head gasket...new head/carb gasket...new fuel line. Has clean tank with internal screen that looks fine. Wandering if the points may be the problem? OR could a fouled plug be a problem? OR could a bad coil to spark plug wire cause any troubles? NOT an expert and getting very frustrated at this point. HELP PLEASE.... Share this post Link to post Share on other sites
KATO 115 #2 Posted October 29, 2012 I would try another coil ...sometimes when they get hot the windings expand inside. When they cool off they work again. Share this post Link to post Share on other sites
rydogg 186 #3 Posted October 29, 2012 It sounds like a spark issue I would go through the electrical system and check or replace each part (coil, condensor, points, spark plug, wires, ignition switch). I was having trouble starting my sons go kart...after pulling and pulling I finally changed the spark plug and it started on the first pull and runs excellent. Pick up a spark tester and check for spark with the plug installed. Below is a picture of a spark tester that I use to troubleshoot spark problems this works great since you can use it with the plug installed in the head since sometimes spark is lost under compression and this usually indicates a bad coil. Share this post Link to post Share on other sites
hcminis 1,700 #4 Posted October 29, 2012 Has very good spark. Took the plug out and can see blue spark very clear. Share this post Link to post Share on other sites
buckrancher 2,694 #5 Posted October 29, 2012 change the points and condenser Brian Share this post Link to post Share on other sites
roscoemi 245 #6 Posted October 30, 2012 :text-yeahthat: I agree with brian. I had a probblem with my c-121, sometimes ran sometimes not so much. Chased the fuel system till the cows came home, but changed the condenser and it runs great now. It had spark, but not very good with fuel and compression. Share this post Link to post Share on other sites
