mercury 500 50hp thunderbolt engine carb questions 3572822

[newsomeford]

got this thing off a friend and built carbs cranked it today not sure on year but run good but i dont know where to set my two adjusting screws on carb or how to set my idle if anyone has any help id appreciate and if anyone knows year that be great thanks

 

[Chris1956]

Re: mercury 500 50hp thunderbolt engine carb questions 3572822

You should pick up a service manual. It will have step-by-step instructions on how to link and synch that motor. L&S is real important to have the motor run correctly and not blow it self up.

That motor looks to be a '73, and has side bowl carbs. Carbs will have only idle mixture setting screw on them. Set idle mixture screw 1-1/2 turns out from lightly seated and adjust from there.