1985 Mercury 115 hp power loss

85Lund

Cadet
Joined
Aug 24, 2008
Messages
18
Hello,

I have a 1985 115 hp Merc outboard and it seems to have lost its power on the hole shot. I was coming in from fishing last night running about 4000 rpm and the motor nearly died. I backed off the throttle and put it in neutral. It idles well and starts great still. I just lost the power. When I engage the throttle and try to plain out now it seems as if it wants to die if I give it too much gas it will die. I need to really feather it to get it plain out. I was experiencing a problem when the primer bulb was pumped hard gas would come out of the carbs. Would this have anything to do with it?

Its my first post and Im not too familiar with outboard motors,so if you would like more detail please let me know.

Thanks,
 

chrisg

Chief Petty Officer
Joined
Jun 29, 2004
Messages
476
Re: 1985 Mercury 115 hp power loss

checked for a rope or fish line around the prop?
 

85Lund

Cadet
Joined
Aug 24, 2008
Messages
18
Re: 1985 Mercury 115 hp power loss

I did inspect the prop after taking the boat out of the water. I do not have a prop wrench so I was not able to ake the prop off and look. Will do so this weekend.

Thanks for the reply.
 
Joined
Dec 26, 2008
Messages
4
Re: 1985 Mercury 115 hp power loss

Check the stator output - I had this go bad once on my 87 tower of power - it had same problem - disconnect wiring harness from stator ring and check resistance of coils using and ohm meter.
 

allenprimo913

Seaman
Joined
Dec 27, 2008
Messages
63
1988 mercury 115 or 110 hp

1988 mercury 115 or 110 hp

:(

:(

im loss where can i start a thread

i need help

tnks
 

allenprimo913

Seaman
Joined
Dec 27, 2008
Messages
63
115 hp mercury hard start bt will run for few minutes then dies and hard start again

115 hp mercury hard start bt will run for few minutes then dies and hard start again

hi,

i know i posted on the wrong page but im loss and need help bad

my first baot and i am a newbie so please help s highky appreciated

i have this 1988 ebbtide outboard i prchased from a craiglist guy and im trying to get my moneys worth. i started it lost of times and not too lucky
it runs for few minutes then dies on me and hard to start again. its about 40 degrees when i did this. pump primer till get hard, squirt carb cleaner to carbs
and started again. fires for few minus then dies.

now, its different, hard to start, if it runs it dies then cant start no more
found out it kills the battery, charged battery then starts then dies again then hesitate to start because the battery's weak.

i have i guess a 115 hp inline with three carbs

bottom carbs seem to be firing working but top two dont, 4 top plugs seems to wet but bottom 2 dry

what s the meaning of this symptoms?

seller told me is a 110hp but i doubt it and he said he rewired the boat?

soes it mean the motor, he did the trailer old me new wirings but not one works?

cant locate the ******* no more, hes' gain for now spending my xmass money
my loss

:( :(

thanks guys for help
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,864
Re: 1985 Mercury 115 hp power loss

Allen, It is hard to diagnose. First get a service manual. Next take compression readings on all cylinders. They should be 100PSI+ and within 10% of each other. Next check for spark on all six plug wires with an inductive timing light. Report back your findings. With any luck your carbs are just dirty, and the rest of the motor is good.
 

allenprimo913

Seaman
Joined
Dec 27, 2008
Messages
63
115 hp mercury hard start bt will run for few minutes then dies and hard start again

115 hp mercury hard start bt will run for few minutes then dies and hard start again

thanks for the response

this is what i found out

the sparks are all good

the compression shows within 135 down to 122psi bottom the lowest

i checked my groundings point and replaced some corroded wires i havent started yet because i suspect the starter to be grounded or shorted to ground.

it shows 1.2 ohms from the positive terminal to ground so im not sure of this no cables attached just the starter bolted to the motor. i should not see any connection between them, right?

if its ok, is it safe to start?

one more thing if i pump the primer, it goes hard but it goes soft and i see fuel
coming out of the bottom carb? is this normal? but i dont see on the 2 top carbs.

WHAT SHOULD BE THE RIGHT GAS RATIO? i used 32:1 and can i squirt carb cleaner while starting? do i have to press on the choke (closing the flap of the carb while starting) is this the proper way to start on cold engine?

thanks for the help
:confused:
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,864
Re: 1985 Mercury 115 hp power loss

Allen, Your compression numbers are good. Since you alos have spark, the trouble is likely carbs.

Fuel should not come out of any carb. It sounds like you have a stuck inlet needle on the bottom carb. Fuel mix is 50::1, which is 16 oz oil to six gallons of gasoline.

I am not sure what resistance value you are reading.

Starting procedure is to pump primer bulb until hard, lift cold start lever on MerControl and hold choke closed when cranking. I would mix some fresh fuel, hook up a flush device and try to start the motor. You may run it a few minutes and see how it does. You wil likely need to clean and rebuild the carbs,
 

allenprimo913

Seaman
Joined
Dec 27, 2008
Messages
63
115 hp mercury hard start bt will run for few minutes then dies and hard start again

115 hp mercury hard start bt will run for few minutes then dies and hard start again

thanks for the response

i have not work on the boat for few days now because of the weather , i live here in sacramento and it gets cold too on winter

anyway, what i am talking about is the starter , i took it off the motor and checked for short.

what i see is 1.2 ohms resistance from the terminal connected to the solenoid relay to the body of the starter.

there is only one terminal on the starter . does this mean the starter is shorted?

i will work on the bottom carb when the weather is littlte warmer, and you are right i should not see any fuel coming out and the primer should stay tight
but it get loose if i pump it again.

thanks and happy new year!!!
 

allenprimo913

Seaman
Joined
Dec 27, 2008
Messages
63
115 hp mercury hard start bt will run for few minutes then dies and hard start again

115 hp mercury hard start bt will run for few minutes then dies and hard start again

oh i forgot.

i dont have a lever for cold start, i only have the button choke it closes the flaps for the crabs when press.

if i move the forward/back lever it will not start, it has to be on neutral then press the button i guess

so when i rev the motor i have to put the lever to forward which engage then propeller spins while im reving

is this right?

how can i rev my engine?
 

CharlieB

Vice Admiral
Joined
Apr 10, 2007
Messages
5,617
Re: 1985 Mercury 115 hp power loss

Allen,
You may have a Merc control where the whole control arm will 'pull out' from the control box, grasp the arm at the central pivot point and see if you can pull it outwards about 3/8 inch, hold it there with your left hand while using the right to squeeze the release latch and push forwards as if going into gear, it won't go into gear but will rotate about 30 degrees and then you will feel it begin to open the throttle.
 

allenprimo913

Seaman
Joined
Dec 27, 2008
Messages
63
115 hp mercury hard start bt will run for few minutes then dies and hard start again

115 hp mercury hard start bt will run for few minutes then dies and hard start again

i dont have any idea but i will try that when the weather warms up and thank you very much.

happy new year will let you know the result soon i lay my hands on it the first year


thanks again
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,864
Re: 1985 Mercury 115 hp power loss

Allen, The starter has a single connection point, and the body of the starter is grounded. I have never measured the resistance across the starter, but your reading is likely in the ballpark, at least. If the starter will spin the motor, it is good. Make sure the connections are clean and tight.
 

allenprimo913

Seaman
Joined
Dec 27, 2008
Messages
63
115 hp mercury hard start bt will run for few minutes then dies and hard start again

115 hp mercury hard start bt will run for few minutes then dies and hard start again

thanks a lot vice for the quick response

i think all starter are made that way, a friend told me im measuring the resitance of the winding of the motor.

anyway, i havent touch it and plan to do it sometime next week, have to finish some rewirings too because i saw some wires taht are corroded especially the ones coming from the stator.

i seem to have problem too determing what s the real specs of my motor, it has a nmber stamped on the head 836-1852 and i dont see any cross reference to this number when i look at mercury motors.

i know its an inline six with 3 carbs and two coils, one more thing i obsered is the switch box has only 3 terminals to it and 3 wires connected, 2 yellow and one red in the middle. i looked at mercury outboard parts and theres no one the same as what i have.

i ordered a manual and i should be getting soon

thanks again:confused:
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,864
Re: 1985 Mercury 115 hp power loss

Allen, The three wire device with two yellow and one red wire is likely the rectifier. That motor will have either a distributor (Pre 1979) and a single coil and a single switchbox, or a ADI Ignition (post 1979) with six coils and two switchboxes.

Both ignition systems share a common rectifier.
 

allenprimo913

Seaman
Joined
Dec 27, 2008
Messages
63
Re: 1985 Mercury 115 hp power loss

hello vice,

if its the rectifier then i dont see any switchbox

i see distributor and two coils but can not find the swicthbox

it says thunderbolt ignition on the front cover though.

thnks
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,864
Re: 1985 Mercury 115 hp power loss

Allen, There are three wires (black, white, brown) that run from the distributor to the switchbox. The switchbox is mounted on the front cowling support. The coil may be big and red (older motors) or small with a aluminum housing. The old style rectifiers were big and red as well, the newer ones small square and black. It sounds like you have a pre 1976 motor. Clean the inside of the distributor cap. The rotor does not come off of it's shaft. Don't even try to remove it or it will break and cost you $200+ to repair.
 

allenprimo913

Seaman
Joined
Dec 27, 2008
Messages
63
115 hp mercury hard start bt will run for few minutes then dies and hard start again

115 hp mercury hard start bt will run for few minutes then dies and hard start again

hi vice,
thanks for your reply

this is what i saw inside the motor
i believe its not 1976 either
it has two coils that goes to the distributor at its end

there are only 2 wires coming from the distributor going to the stator

6 wires coming from the stator
2 brown & white going to the 2 coils
2 brown & white to the distributor
2 yellows to the rectifier

thats all i can see

im lost i ordered a manual i thought my motor would be 1975 - 1995

any suggestion what would be my motor is? year, type, kind or even brand?

thanks again:(
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,906
Re: 1985 Mercury 115 hp power loss

The only Merc I can remember with 2 coils going to the distributer is a 1100 and that will be a 1966 or 67 year model. What is the serial number of engine?
 
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