I have a moter that starts out of water but wont start in the water

[pauly_porkchop]

"please help, its my parents b

"please help, its my parents boat and they need help, thank you."

 

[fastjeff]

"Explain in detail, like what

"Explain in detail, like what kind of motor it is.

Jeff"

 

[pauly_porkchop]

"it is a mercury 50 hp from ab

"it is a mercury 50 hp from about the 80's, when they start it out of the water it works but when they put it in the water it wont start."

 

[beckerjs]

"compression and spark test, i

"compression and spark test, if it passes service the carbs. My bet it fails the compression test."