1981 Mercury 115hp cold start troubles

B

BDub

Cadet
Joined
Jul 28, 2002
Messages
22
I have trouble getting the engine to start for the first time when i get in the water. It just turns over and over and over. Doesnt sound like its really firing. I push the throttle button on the stick and ease the stick forward, and i push the key in for the choke while starting, but it takes forever to start. <br /><br />Eventuallly it acts like its trying to fire, and the starter quits. so i turn the key off, then back on and it does this again a few times. It eventually starts up. After its warm, you can kill it, and fish a while, then you barely have to turn the key over and its running. Starts like a dream when its warm. But when the engine is cold, its a real nightmare.<br /><br />Could it be the plugs, or my battery too weak? I'm clueless. Always heard they were hard engines to start, but this is getting to me. Thanks folks.
 
T

The Marine Doctor

Commander
Joined
Jul 25, 2003
Messages
2,177
Re: 1981 Mercury 115hp cold start troubles

The engine is not creating suction in order to adequately pull the fuel while the engine is choked.<br /><br />Try a Decarb.<br /><br />TMD
 
Z

ZmOz

Captain
Joined
Aug 13, 2003
Messages
3,949
Re: 1981 Mercury 115hp cold start troubles

Yeah...get a can of seafoam and spray it in every hole you can find. :)
 
G

greasemonkeyozi

Petty Officer 1st Class
Joined
Jul 16, 2003
Messages
282
Re: 1981 Mercury 115hp cold start troubles

This sea foam stuff works wonders. Everytime I hear the word sea foam, I go off on how good this stuff is. Its a tune up in a can. <br /> Take your spark plugs out, and spray a good amount in each cylinder. Let set for an hour or over night, and start your motor. Then spray some in your carbs while running. Then watch all kinds of nasty stuff blow out your exaust. You'll be suprised. Use 1/2 can per every 3 tanks fuel. Keep that system clean. <br /> You can get an aresol can of sea foam at NAPA. I havnt been able to find any else where. :p
 
B

BDub

Cadet
Joined
Jul 28, 2002
Messages
22
Re: 1981 Mercury 115hp cold start troubles

I looked at the iboat megamall and at napaonline.com for seafoam, but cant find it. I'll continue looking though. Also, are there instructions on how to do the decarb with seafoam or whatever i need to use? I dont wanna screw this engine up. <br /><br />The last few times i tried to start the engine at home using muffs, it hasnt started. I just quit because i get frustrated. Would it hurt to spray something in the carbs just to get it to fire, then let it suck the gas through on its on? Then i could use the decarb stuff, right? <br /><br />I'm curious to see how much junk this thing will blow out of the engine !!!
 
N

NEECAPRS

Petty Officer 2nd Class
Joined
Jul 25, 2003
Messages
126
Re: 1981 Mercury 115hp cold start troubles

ZMOZ: Are Deep Creep and Sea Foam the same thing? :cool:
 
V

vista4u2

Seaman Apprentice
Joined
May 26, 2003
Messages
43
Re: 1981 Mercury 115hp cold start troubles

DBud - I have the same starting problem with my 84' 115 in-line 6 Mariner -would NOT start cold without major starter wear and tear. So my solution is this - I remove the front cover, squeeze the bulb till hard, go to throttle only on my controls to about quarter throttle, press the key in to choke (I have the fuel enricher system), enrich it, and squeeze buld again. Now the trick - I have identified 3 holes in it that I can use to get one of those typical small red spray tubes through, and at what angle I need to insert it so it ends up inside the carb throat, and then spray starter fluid into each carb, and she starts right up. Note: I had to modify the tip of the spray can to add the red tube because I couldn't find a starting fluid brand that fitted them. Guaranteed to work!
 
M

mellowyellow

Vice Admiral
Joined
Jun 8, 2002
Messages
5,327
Re: 1981 Mercury 115hp cold start troubles

starter fluid removes lubrication, not a good idea!<br />better idea to have the carbs and fuel pumps<br />rebuilt if the motor has good compression.<br />one of our members, Bear has an ingenious<br />solution he has posted several times.<br />try a search.<br />good luck,<br />M.Y.
 
V

vista4u2

Seaman Apprentice
Joined
May 26, 2003
Messages
43
Re: 1981 Mercury 115hp cold start troubles

The starter fluid I use has lubricant in it - Pyroil. I had totally upgraded my fuel system from tank to rebuilt carbs and everything in between, and it made no difference whatsoever to ease starting. I have concluded that the split second of running on lubricated starting fluid is worth not grinding away on my electrical system, not to mention the frustration.
 
M

mellowyellow

Vice Admiral
Joined
Jun 8, 2002
Messages
5,327
Re: 1981 Mercury 115hp cold start troubles

you should also look at the set up Bear invented<br />for his inline 6. guess I'm lucky, my 1150 fires<br />right up.
 
Z

ZmOz

Captain
Joined
Aug 13, 2003
Messages
3,949
Re: 1981 Mercury 115hp cold start troubles

Yes, "Deep Creep" is just Seafoam in a spray can. Start your engine and let it get warmed up. Get it to about 1000 RPMs and spray it in the carbs while it is running...use about half a can. Then take out the spark plugs, clean or replace them, and spray some more seafoam into eacy cylinder, let set for a while. Then start it up and watch in shock how well it works now. :D The only place I have been able to find seafoam is in Napa stores - not Napa online. It's strange, this product is so GREAT, why is it so hard to find?! :confused:
 
S

skier

Petty Officer 1st Class
Joined
Jan 31, 2002
Messages
336
Re: 1981 Mercury 115hp cold start troubles

I must either be lucky or I have found the only way to start these inline 6 motors. Cause my 1979 140 fires up pretty easy (Less than 30 seconds on the starter).<br /><br />I do as follows.<br /><br />A. Pump bulb until hard (My motor doesn't care if it is tucked under or at full trim)<br /><br />B. Engage Throttle Only operation and use about 1/4 throttle.<br /><br />C. Turn key on and push for the shoke (I don't have an inricher system)<br /><br />D. Crank her until she fires.<br /><br />E. After she fires, let go of key/chock and bring RPM's down to 1300<br /><br />Works every time.<br /><br />Craig
 
B

BDub

Cadet
Joined
Jul 28, 2002
Messages
22
Re: 1981 Mercury 115hp cold start troubles

i ran a search using bear's member number, but the phrases i use for search are not turning up any results. could you give me a line or a few words i should search for? thanx a bunch.
 
G

Gold Bear

Petty Officer 1st Class
Joined
Sep 26, 2001
Messages
224
Re: 1981 Mercury 115hp cold start troubles

mellowyellow <br /><br />Thanks for the kind words.<br /><br />Merc140 I think you are lucky, judging by the number of members who post problems about how hard this old I6's are hard to start. <br /><br />Without my "rig" my engine will start after about a minute of trying (using the same method you recommend). With my rig it starts after about 5 seconds at the most, and I do not even use the cold start lever any more.<br /><br />Regards to all,<br /><br />Gold Bear ;)
 
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