1992 25 hp mercury runs great for ten minutes

[hunt4life69]

hello there i am hoping this motor is not hurt internally but that my next step unless someone has an ideal is to tear it down. the motor starts and runs fine for mabe 10 minutes then it starts to bogg down goes from full throttle down to mabe half throttle then only mabe quater throttle is all it will do without bogging down and idle is fine even after it starts this. there is no water in fuel the bulb is hard , but if any body has a clue i would appriciate the info. thanks craig

 

[jackd1023]

Re: 1992 25 hp mercury runs great for ten minutes

sounds to me that it is overheating....is the tell tale pumping?

 

[hunt4life69]

Re: 1992 25 hp mercury runs great for ten minutes

yes the water pump is pumping water and the motor doesnt seem hot to the touch.

 

[crem1]

Re: 1992 25 hp mercury runs great for ten minutes

If adjusting the carburator does not help then cleaning it in a solvent and replacing the interior with a carb kit should help

 

[hunt4life69]

Re: 1992 25 hp mercury runs great for ten minutes

i have already rebuilt the carb new fuel pump nem choke , what im thinking is one of the coils is breaking down under load and heat .