Drivebywire 0 #1 Posted June 14, 2014 I have the Kohler 12.5 Pro Series engine in my 312 and it's been working well ever since I've had it. Recently, the engine will periodically start to mis-fire/backfire until it quits. Trying to restart it immediately produces the same problem. If I wait @ 5 minutes it starts right up and runs until the problem starts again. When it happens I pull the PTO off but it doesn't make any difference. My first thoughts are that it's an electrical issue but I'm not sure where to start. Any help would be appreciated. Share this post Link to post Share on other sites
skrusins 128 #2 Posted June 15, 2014 Sounds like Vapor lock problem, the wether here in Ohio has been hot and muggy. Also see if fuel pump is working. Share this post Link to post Share on other sites
6wheeler 669 #3 Posted June 15, 2014 Check out the coil. Sometimes they will start to falter when they get hot. Then when cooled down they will run fine. Share this post Link to post Share on other sites
Drivebywire 0 #4 Posted July 4, 2014 Thanks for your answers. The problem seems to have become worse as it won't start at all now. I've removed the carb bowl. It had some dirt in it but plenty of fuel. I also replaced the spark plug. That's when it wouldn't start. I checked both plugs by cranking the engine with the plug out. Both of them fired but the spark rarely hit the tip of the electrode on either one. Instead it went off to the side and was not a fat blue spark. Is there a way to test the coil or does anyone have any recommendations where else to look? Share this post Link to post Share on other sites
