Home › Forum › Ask A Member › ’77 OMC 9.9hp hard start warm › Reply To: ’77 OMC 9.9hp hard start warm
Yeah, kinda seems like you might be losing spark as the engine heats up…But, does the engine continue to run fine when hot? Kinda sounds like the engine runs fine until you shut it off, which makes a spark issue a little less likely. So, like Bill says, it is best to check spark when it is hot and won’t restart…Could be something as simple as a bad ground, or funky stop switch. But, you really need to confirm whether or not this is a spark issue before digging into the ignition system.
What happens if you shut the engine down, then restart it immediately, does it start up OK then? Keep, in mind that you may need to use the choke when restarting a hot engine that has sat for a bit…Seems counter intuitive, but today’s fuels tend to vaporize easily, especially in hot climates. Are you trying to restart at idle speed, or are you turning the throttle up to “start”? Keep in mind that the neutral lock out RPM is adjustable on those older models. There is a stop held in place on the shift detent that can be moved forward/back a bit to raise/lower max RPM in neutral, perhaps you need to advance the throttle more when trying to restart hot…