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1981 115 Merc Carb or Gas problem

D

Dave Ervin

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" I have a 1981 inline 6, 115

" I have a 1981 inline 6, 115 HP starts fine, idles fine up to about 10 mph, when I give it the gas it just spudders. It won't get up and go. I rebuiilt the fuel pump hoping this would fix the problem to no avail. I had the motor checked out, compression is good, ignition is good from a mechanic. He wanted the boat for 2 days and I was in the middle of a fishing trip to Alabama, we said no,so we ran on idle speed only. Please any insight would be helpful. I believe the carbs are not getting gas. Any suggestions I am on a tight budget.
Thanksl
Dave "
 
" I had the same problem a few

" I had the same problem a few weeks ago, spent a lot of time checking out the fuel and cleaning carbs but nothing worked. Find you a good merc. guy that is over 45 years old and has the proper diagnostic equipment and ask him to check the stator...especially if you can get to around 17-1800 rpms and thats it before she chokes up on you. "
 
" p.s. i can recommend a guy

" p.s. i can recommend a guy in the Nashville, TN. area if you are anywhere near there "
 
" Dave,

Here's how

" Dave,

Here's how to check if the carbs are getting gas:

First pull the man over board kill switch for safety, and pull off the spark plug wires. Disconnect the fuel line that feeds the three carbs, after the fuel pump and filter. Squeeze the primer bulb and observe unrestricted fuel flow (if not, the problem is not pump or carb related). Next, turn the engine over, you should see a steady pulse of fuel coming out of the line being pumped by the fuel pump. It won't be a stream, just a pulse. If there is no pulse, or if it dies out completely after 5 seconds, you have a problem with the pump.

If the pump is OK, I'd be 90% sure of a carb problem. I've been through the exact same thing with mine; what's happening is the fuel to air mix is becoming way too lean due to a fuel restriction. Carbs get clogged mostly by varnish that forms from sitting as the fuel evaportates. This problem possibly may be fixed by just richening the low speed jet (turn each out 1/4 turn), but chances are your carbs are clogged and adjusting for a clogged carb is a bad idea. They need to be pulled, taken apart and cleaned with special attention paid to the jets. Rebuild kits are under $20 a piece, and well worth it. Be sure not to unadjust the linkage when you do this, as the top carb is what drives the others and getting that out of whack will mess up synchronization. When putting the carbs back together, lightly snug the low speed jet needles down and then back each off 1.5 turns. Re-adjusting the low speed mix is a little tricky, but far from impossible, if you need help on it, get back to me on it.

Another thing to look at, just for the heck of it; there is a long thin vacume type hose that runs from the top of the powerhead, down to the bottom, behind the large silver bracket that holds the electronics and black boxes. There are plastic fittings entering the powerhead that it attaches to. This lubricates the top and bottom bearings on the crank. Mine had been sheared on the bottom and for some reason the engine seemed to run better after I re-attached it. I suspect it has something to do with crankcase sealing.

Tell us how you do,

Jon "
 
" Dave,

One more th

" Dave,

One more thing; you may want to try using a fresh fuel supply, just to be sure that it's not something that simple.

Jon "
 
" All,
I drained all of the o

" All,
I drained all of the old gas and put new oil and gas in the tank, about a month ago, after the trouble started.
To Jon,
Where can I get rebuild carb kits, I live in KY?
Do you adjust the jets while it is running?
Do you have an email address for help or a phone
number? What is a stator, where is it located, is it expensive and hard to replace?
Thanks,
Dave "
 
" dave, there is a guy in flor

" dave, there is a guy in florida who can help you with the carb kits.rick @ 407-343-4733 i got mine for $14.00 each and came with needle and seats. the dealer here wanted $18.00 just for the needle and seats ea.! and i have three carbs. now mine is a 75 horse chrysler but i am sure he will do you right.had mine in 2 days. just tell him jim in north carolina sent you. he can probably help you with your running problem too. good luck.Jim King "
 
" The stator is located under

" The stator is located under the flywheel right on the top of the motor. I wouldn't attempt this replacement unless you have a puller-things could get expensive in a hurry with a broken flywheel. Follow Jon's advice first before you spend any money. you can take a flashlight and look at the stator and possibly see if there are obvious problems (melting, or gooey substance)or broken or exposed wiring. the number of wires i think depends on if you have a distributor type ignition or not. "
 
" I had the same problem and i

" I had the same problem and it was simple, buy a new fuel line from the tank to the outboard and make sure you dont use the same bulb. It made my 69 merc run like a charm. "
 
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