Stuck carb screws 1971 mercury 800

[1971 glasspar]

Hi all. I searched. Im rebuilding the twin side bowl carbs on a mercury 80hp 1971. It ran well last year but was hard to start. I figured it was fuel plumbing issues. This year it wouldnt start at all. So, after some diagnosis, the carbs are plugged so bad that fuel just isnt flowing through them at all. Most likely rust sediment as none of the filters I used would take ALL of the rust color out of the gas. I tried though. The whole fuel system needed cleaning and redone, and thats what I did. Anyway, Carbs are off, but the brass screws are all stuck with some thick redish brown glue. It might be red locktite? Ive got carb kits coming in, and I need to get these screws un stuck. Any suggestions? In searching, I havent found any topics at all covering this, here or elsewhere.

So far the carbs are disassembled as far as I can, and soaking. Pretty sure theres some jets and screws and such that need cleaned under those brass screws though.

Suggestions and links greatly appreciated. Thanks!

 

[Chris1956]

The factory used something like that to seal the carb brass plugs. I never found it difficult to remove. It was like nail polish.

You probably do not need to remove all the plugs to clean the carb properly. The bottom stbd hex over the main jet and the top slotted plug over the idle jet should be removed to facilitate cleaning.

If they won't come off (don't break them), soak that mother for a few days in a good carb cleaner and blow out all the passages. It should be clean enough. Replace float, inlet needle and gaskets. Set float height and idle mixture and retest on motor.

 

[1971 glasspar]

I was hoping that the passages would be large enough to possibly get clean even without 100% disassembly. Unless the soaking helps, Im guessing that if the carb cleaner dosent soften the glue, then heat might be the only option. Unfortunately I couldnt remove the plastic intake vanes that straddle the main port in the opening of the carbs. Hopefully they arent ruined. My first guess is that the stuff is red locktite applied in large dollops. Its obvious somebody else also tried as the screw heads are slightly damaged where the screw driver has slipped.

 

[Chris1956]

Skip the heat. Remove the hex plug and the one on top of the carb near the throat. Pull the carb cover and soak that baby for a couple of days. The solvent should not hurt the plastic parts. You can then use some spray carb cleanter to clean the main jet via the hex bolt, and the idle jet via the top brass plug. Clean the main nozzle, and the idle passages. Look for some pin holes in the throat on the bowl side. Those are for idle air. Get everything clean and rebuild with new floats, gaskets and inlet needle and seat.

 

[1971 glasspar]

Carbs are cleaned and rebuilt. Only used very few parts from the kit. I ended up using the old inlet needle and seat because the new ones required adjustment for clearance. Old ones seemed fine. One last hitch, the throttle linkage is broke. Its the white plastic linkage that goes between the carbs to make them move together. Its always something!