2002 Yamaha 4 stroke smoking

[DJ II]

I recently bought a 2002 Yamaha F100TLRA four stroke. It starts and runs great. However after running on plane at high rpms and coming back to idle it is has white smoke coming out the exhaust. This is my first four stroke motor. Is this normal? Does this mean it is running hot? The boat does not have a temperature guage.

Thanks

 

[rodbolt]

Re: 2002 Yamaha 4 stroke smoking

have you tested the alarm system?
have you checked the maint history for the last COOLING system tuneup?

 

[DJ II]

Re: 2002 Yamaha 4 stroke smoking

The guy I bought it from said that it overheated on him back 3 months ago when he ran at full rpms. He said it had scale buildup in the cooling passages. He had all of this cleaned out and said it ran fine ever since. He also had regular maintenace performed i.e. changing plugs, replacing impeller, changing oil, etc.

 

[DJ II]

Re: 2002 Yamaha 4 stroke smoking

This guy also replaced the power head gasket. Does it sound like a bad cylinder or the gasket leaking?