Re: 1998 Evinrude 115 warm starting problem
Have you checked spark while its hot and not firing to rule out an ignition component failure? Also check the cranking voltage at the starter solenoid on the hot motor. More likely a fuel delivery issue due to your explanation but cant hurt to investigate.
Regarding a fuel issue, may be a sticky float, or carb overflow. When were the carbs last rebuilt? Will advancing the throttle in neutral and running it at high idle for a minute clear it up? Also stop using starter fluid, use pre mixed fuel in a spray bottle. Starter fluid has no lubrication in it.