Suzuki dt60 bogging down

[Lisbon]

I have a problem with a suzuki dt60. Maybe someone could help. It fires up and idles like a new motor. When i leave the ramp it runs at wide open perfectly like a new motor. After about 15 min of wide open. The rpm drops imediately to just above idle speed. If i kill the motor to where it stops turning. Imediately restart it and it will imediately restart and idle perfectly. Hit the throttle run perfectly again
for a few minutes Then drop again. the symptons are consistant. Replaced the tank fuel lines filter and bulbm

 

[99yam40]

Not sure about your motor, but some suzukis had a water level switch in the block along with an overheat switch.
also they had an oil flow switch .

do you have gauges that will tell you when these problems show up?
does the warning alarm work as it should?