1982 115 merc HELP...

rich6969

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Aug 18, 2010
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6
HI ALL.......

I really need HELP ..... Long story short i picked up a 16ft bajass with a 115merc.... When i first got it i couldn't get it STARTED. I sent it a local backyard mechanic and he got it running for me....My problem is this...

The boat Idles nice at home on muffs, Once i get it on the water it starts nice and idles, once i stick it in gear IT BOGS and wants to die....I AM FLUSTARD ....
 

Chris1956

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Mar 25, 2004
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27,036
Re: 1982 115 merc HELP...

Likely dirty carbs or misadjusted idle mixture. If the carbs are clean, richen the idle mixture a bit and see if it improves. Use fresh fuel for all testing. It makes a difference
 

kungpaoshizi

Petty Officer 1st Class
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Apr 29, 2013
Messages
221
Re: 1982 115 merc HELP...

I was having all sorts of issues with it bogging down etc, I finally said screw it, replaced all plugs, plug wires, and skipped cleaning it and bought a new one, but the distributor cap.

Runs like a champ now.. the plug wires looked absolutely fine, but after changing them I got a 300 rpm boost..
 

rich6969

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Aug 18, 2010
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Re: 1982 115 merc HELP...

plus, wires all new... Carbs cleaned.... so i called the guy up and told him what the boats doing, he said "" he suspect he didnt set the High and low speed jets right.... can any chime in on this ?? i honestly don't want to bring the boat back to him and after reading and readinf i know he didn't set the idle in water under load ...:facepalm:
 

Chris1956

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Mar 25, 2004
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Re: 1982 115 merc HELP...

High speed jets are not adjustable. The mechanic should know that. The idle mixture must be richer than other motors, to allow acceleration. Idle mixture must be set under a load, ideally in the water with the std prop, and in gear. A test tank and a prop, might be suitable to set under load.
 

rich6969

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Aug 18, 2010
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Re: 1982 115 merc HELP...

High speed jets are not adjustable. The mechanic should know that. The idle mixture must be richer than other motors, to allow acceleration. Idle mixture must be set under a load, ideally in the water with the std prop, and in gear. A test tank and a prop, might be suitable to set under load.

so why would he say that :confused:.... he said thet screws are adjusted inside the carbs ?? should i be taking about the carbs again or try adjusting idle mixture first...like i said it runs nice on muffs ... sorry i can do just about anuthing but i get very scared when it comes to carbs........
 

Chris1956

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27,036
Re: 1982 115 merc HELP...

OK, according to the parts list, you have sidebowl carbs. You want to see the high speed jet, remove the brass hex bolt in the base of the carb. The fixed high speed jet is right behind it. It should be installed snugly into it's seat. The only adjustment is the idle mixture adjustment, which is obvious.
 

rich6969

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Aug 18, 2010
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Re: 1982 115 merc HELP...

thanks Guys.. i played with the motor last night, had it set in a Tank and got the idle set in gear on low....maybe 8000rpm... I throttle down and it didn't bog down....even blew all the water out of the tank.:embarassed:.. is this a good thing ???.. second question i have now is this.... are these motors designed to leak gas after the engine is turned off from the carbs? also somthing i noticed that bugged me only because i know nothing about these engine was this in my exhaust port... good or bad ? Picture 029.jpg
 

Chris1956

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Mar 25, 2004
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27,036
Re: 1982 115 merc HELP...

Carbs should not leak gas, unless motor is tilted up. Sounds like it is time for a water test. Take your screwdriver and leave the wrap cowl in the car.
 

rich6969

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Aug 18, 2010
Messages
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Re: 1982 115 merc HELP...

Carbs should not leak gas, unless motor is tilted up. Sounds like it is time for a water test. Take your screwdriver and leave the wrap cowl in the car.

*** thanks i am water testing it tonight.....any hints on what adjustment i should be doing on the water ..
 

mr 88

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Nov 3, 2010
Messages
2,115
Re: 1982 115 merc HELP...

As noted above,turn the low idle speed screw out the width of the screwdriver blade,starting with the top and move down from there.Do one at a time,then test,it does not take much for it to hit the sweet spot,hence the one at a time,along with the fact if it runs worse you can go back to the ONE idle screw and re-adjust.
 

rich6969

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Aug 18, 2010
Messages
6
Re: 1982 115 merc HELP...

UPDATE.... after hours of playing with the Carbs in the water last night and no luck, we unpluged the idle stabilizer......AND SHE CAME TO LIFE..... Synked the carbs .....WOW she is a ROCKET.... scary almost..... happy happy happy
 
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