2005 15HP 4 Stroke Mercury outboard pull start motor

[tommyboi707]

I am having problems with my motor dying/cutting out after the motor is warmed up and when I give it gas it bogs out and dies. I have not problem starting it back up but I do notice that the motor sounds louder and rougher than when I first started it. I am able to use the motor for about 5 mins or so but when I give it full throttle it tacks out like it is redlining then dies. I had the impeller replaced, got the valves adjusted and replaced the fuel filter and oil. any suggestion on what to do next. also, when I start up the motor, water comes out in a good stream out of the motor but after it is warmed up or when im going, the water stream cuts down and trickles. thanks for any help I can get.

I am also having trouble finding my serial number for my motor so it is very difficult to get parts for the motor. I don't know how my local marine repair facility was able to find the correct parts but I've looked everywhere and even contacted Mercury myself. any tips on how to find the correct serial number for my type of motor?

 

[raczekp1]

powerhead is taken from yamaha 15 hp, lower unit is taken from mercury 2 stroke.
so

 

[not enough_water]

if thats the case, then that would explain the curse

 

[tommyboi707]

this does not help me at all. suggestions?