73 mercury bogs out under load

[custompcz1]

I have a 1973 mercury 850 thunderbolt I took it out for first time last week it had sat for 2 seasons unused. Just putted around for a bit and all was fine. So I throttled up was running about 32 mph for 5 min started bogging down and died . It refired back up but could not give it throttle or would bog down again let it idle for a few minute then I could throttle back up again to full speed for a few minutes then same thing again. It would do this over and over. What could cause this?

Here is what has been done it has all new plugs, distributer/rotor, fuel line with primer, and fuel line fittings the one that goes to motor is new mercury fittings but the one on tank is new Johnson fittings that I had in garage don't know if this would make a difference or not.

Thanks for any help in advance..Larry

 

[Chris1956]

Re: 73 mercury bogs out under load

The Johnny fittings are fine, as long as they are in good shape. It sounds like the new ethenol gas loosened some junk in the fuel tank, which is now in your carbs. You might clean and rebuild them.