what year is my merc?

[50 hp merc guy]

my merc is an older thunderbolt 50 serial number 3098755 cant find the year anywhere on here please help me. also when i took it out for the first time it ran great in the yard with the muffs on but in the lake it started and idled great but seems like no top end power i got good spark and fresh gas plugs are new as well engine sat for like a year and a half before i got it. any suggestions ?

 

[Gomer50]

Re: what year is my merc?

Take a look at this site should tell you what year.
www.maxrules.com/Merc_model_files/40-50.html

As for no top end check your compression on each cylinder.You have good spark and fresh fuel,check your fuel delivery,hoses,bulb,fuel filter if you have one,and run some seafoam thru the carbs ( decarb the engine).Possible fuel pump diaphragm damaged and or the carbs just need a good cleaning (rebuild).Most outboards run well in the driveway on muffs because there is no load on the motor.

 

[50 hp merc guy]

Re: what year is my merc?

thank you so much gomer50 im going to try taking the carbs off and cleaning them there pretty basic on this motor, iv got good compression on all 4 cylinders. the carbs have filters on them (2 carbs) and my fuel lines are all good no leaks at all except when i pump the ball up hard the lower carbs needle valve is letting some past out the over flow but only if i pump it hard.

 

[50 hp merc guy]

Re: what year is my merc?

i checked the year as well it looks like its a 1972 merc 50, 500 thunderbolt thanks for the link it worked really good for me thanks again budd.