1975 Merc 115 hp idle

Reg312

Petty Officer 2nd Class
Joined
Jul 12, 2009
Messages
139
Boat ran great in 2009. When I winterized last year I checked compression (110 in cylinders 2,3,4,5 but couldn't get to 1 or 6. Full tank of gas with stable and seafoam. Carbs fogged. Getting it ready this year it started and ran/idled fine with muffs. Put in new plugs with (gap double checked). I've run a few tanks of gas thru this year and noticed doesn't want to idle well and will stall. Runs great WOT and always starts. Just won't idle hot or cold. Will idle all day long with idle leaver up. I've read many post here so will a simple adjustment be in order or carbs cleaned? I plan to rebuild carbs end of this season, just hoping to get away with a simple adjustment till then.
 

75TowerOfPower

Petty Officer 1st Class
Joined
Apr 17, 2009
Messages
331
Re: 1975 Merc 115 hp idle

Quick question what gaps did your plugs have?

They shouldn't have a gap.
 

Reg312

Petty Officer 2nd Class
Joined
Jul 12, 2009
Messages
139
Re: 1975 Merc 115 hp idle

Thats to funny. Spring time is tune up time for all my toys. Tractors, tillers, Car, truck and my old merc 1115. This is what we can call a senior moment and lack of outboard experience. No, they do not have a gap. Replaced them with new ones of same manufacturer and part #. I guess I could really show my ignorance by saying changed the spark plugs in my JD 670 diesel???
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,074
Re: 1975 Merc 115 hp idle

Reg, The only way that #1 cylinder is hard to get to is if you leave the top cowling on. It comes off easy, BTW.

Sounds like your carbs are ready for clean and rebuild. inspect the floats. The originals tended to disolve after a while. The replacements tended to crack.
 

Reg312

Petty Officer 2nd Class
Joined
Jul 12, 2009
Messages
139
Re: 1975 Merc 115 hp idle

Thanks Chris - Any recommendation on a manual to get that will walk me thru the teardown - clean - reassemble procdedure. Is there some kind of PDF online instruction that I can use right away while I search for a manual?
 

Reg312

Petty Officer 2nd Class
Joined
Jul 12, 2009
Messages
139
Re: 1975 Merc 115 hp idle

Is that "Seloc" Repair manual advertised on this site a quality repair manual?
 
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