I have the 18hp v twin on my zero turn cub and I can run around with it and it wont miss, but once I turn the mower on it is lacking power and misfires. I have compression checked each cylinder and each were around 160psi Just for kicks I opened up both overhead valve covers inspecting the springs and rotating the motor slowly to make sure everything was moving and smooth. I have check the spark on each side and found them to be putting out spark although I did notice that one side had a weaker orange spark verses a nice blue spark. I have run sea foam through the carb. I also took my temp gun and shot the exhaust pipes going into the muffler. I did have one side over 300 degrees hotter than the other after a little bit of run time. I have also sprayed carb cleaner by the cylinder to intake off of the carb connection at idle to see if there was a surge meaning the gasket was cracked and leaking. Any other suggestions that I may be missing here?
#2
ILENGINE
first start by pulling the blower housing off of the engine, and make sure the gap between the flywheel and the ignition module is within the .010-.014. After that you may have to install an inline spark tester and check the spark under load. Maybe ignition module cutting out under load. Or possibly just a plug cutting out under load.
Have you tried adding a little choke to see if that makes a difference? Also might disconnect BOTH kill wires from the base of each coil and see if that makes a difference.
Strongly suggest you post engine model number when asking advice.
