50 hp mercury ....got no power

[luigi]

I bought a boat last fall and have been fixing it all spring...it has a 50 hp merc outboart sn c3243903, could you tell me what year it is. It also has a low power problem, I have pulled the plug wires independently and found that only the top two plugs seem to make a difference in the operation of the engine, I have built new wires for it and all 4 plugs have got a good spark, I did a compression test last night, (75 - 85 psi), also when adjusting the idle mixture the bottom carb of 2 does not react to the adjustment, could I have a bad carb? thankyou in advance for any information.

 

[skeets]

Re: 50 hp mercury ....got no power

Hello luigi<br />Welcome yo the forum<br />1972 4 cyl (500)<br />Did making plug wires fix the no fire in the two top cylinders?<br />Did you do a comoression test on the other 2 cylinders.<br />Carbs might need to be removed and cleaned.<br />Good luck

 

[luigi]

Re: 50 hp mercury ....got no power

thanks for the response. yes i compression tested all cylinders and have spark at all four holes. I think I am going to rebuild both carbs and see where that takes me. Anymore suggestions are welcomed and appreciated.