1975 85hp Mercury carb spurts gas

Tony Harkins

Recruit
Joined
May 20, 2003
Messages
4
MY 1975 85hp merc outboard when started gas spurts from what I believe is the idle restriction tube and doesn't idle well at all. Do I need to rebuild the carbs? is something clogged that makes the gas come out like that? From looking at a service manual I think I have a back drag carburetor.I am afraid to operate motor in this condition (may blow myself up).<br />Thanks for any help Tony
 

MercMark

Petty Officer 2nd Class
Joined
May 20, 2003
Messages
149
Re: 1975 85hp Mercury carb spurts gas

I have an 850 of about the same vintage. I'm looking for a powerhead or replacement connecting rods and Cam. Maybe you know some good sources. <br /><br />Don't mean to highjack your thread.
 

emckelvy

Commander
Joined
Jan 16, 2004
Messages
2,506
Re: 1975 85hp Mercury carb spurts gas

Pull the float bowl covers and replace the float needles/seats and the floats themselves. The replacement parts have been upgraded and will perform better than the original factory items.<br /><br />You can get Mercury parts or many auto parts stores (including Napa) can get Sierra Marine aftermarket replacement parts. Replace the float bowl cover's gaskets, if they aren't available separately, ask for what's known as a "carb packing kit", which contains the most commonly used gaskets. <br /><br />BTW unless your carbs are really nasty inside, you shouldn't have to remove them to do this repair. You can remove the main jet plug in the front of the carb (a brass plug that takes a 7/16" wrench), and blow air into the carb from both the float bowl end and main jet end. This'll clear out most any debris which has accumulated over the years.<br /><br />Get a manual such as Seloc, which will show you how to adjust the float level. Very important so it doesn't leak after you reassemble everything.<br /><br />HTH and Good Luck........ed
 

Tony Harkins

Recruit
Joined
May 20, 2003
Messages
4
Re: 1975 85hp Mercury carb spurts gas

Ed thanks for the information, you were right on target found some junk in the needle seat area replaced needle and seat adjusted per the manual<br /> and everything works fine now thanks a lot.<br /> Tony
 
Top