Honda 150 vtec alarm

[marin31623]

Hello everyone ,
About a week ago i bought a fisherman with a honda 150 vtec motor and i took it for a test drive and everything worked fine , the second time i went for a ride about an hour of driving it i heard an alarm ( a beep sound) and the gas went to zero by itself , then i would put it to neutral and give gas again and it would work.
Then after 20 mins it happened a second time and i parked the boat , havent driven it since.
The guy i bought it from said he had changed the impeler and thermostat and showed me the bills , my friends are telling me i have to clear the system with fresh water but i dont want to take the boat out of the sea if its not that.

 

[marin31623]

I dont know if im getting an alarm because of the overheating , when im driving i dont think its throwing enough water tho

 

[chawk_man]

Pull fault codes as described in the attached and post what you find. I don't know the fault codes for the 150, so others will need to jump in.