Motor won't start when hot

[rick_l]

I have a 80's model Johnson 25hp motor. The carb has been bored to increase the hp. When the motor gets hot, it will not start. Boring the carb would not cause this would it? I'm thinking possibly ignition problem or a blown head gasket. I haven't checked the compression yet. Just curious what you guys thought.

 

[tashasdaddy]

Re: Motor won't start when hot

check compression and spark. especially when hot. when you say hot, i assume you mean normal running temperature.