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Help Merc 115 Carbgas 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. It idles fine and runs fine up to about 10 mph. When I give it the gas, it cuts in and out, boggs down and the motor will die unless I ease off of the throttle. Also my primer bulb last nite wouldn't hold prime or pressure. I pumped the snot out of it and it finally held pressure with no results of higher speeds. Also there is some gas leaking (carbs) after I shut it down for a while. Is this normal? Is it OK to pull out the carbs and just clean them? What would I use, what is the best way to do this. I am guessing from all of the input that this is where my problem might be. Any suggestions I am on a tight budget.
Thanksl
Dave "
 
"Dave,

I would start with t

"Dave,

I would start with the carbs. It sounds like you may have a stuck float or bad needle and seat, but first make sure the primer is working properly. If it doesn't hold pressure, either it is not working, or one or more carbs are malfunctioning. Check the valve where the fuel hose connects to the engine also. If it is broken, it will not allow fuel to flow at all.

If you need to remove the carbs, you have to take them apart and inspect everything carefully. It would probably be a good idea to purchase rebuild kits first so that you can replace the important parts.

"
 
" Is this the valve that the f

" Is this the valve that the fuel lines attach to like a connector? How can you tell if it is broken? Easy to find this part, where if needed?
Where can I get rebuild carb kits? Valve?
Thanks,
Dave "
 
"Dave,

Yes, the valve is wh

"Dave,

Yes, the valve is where the fuel hose connects to the engine. There is a spring loaded post which opens the valve. Disconnect the fuel line on the engine side of the valve and see if fuel flows when you squeeze the primer.

You can get all the parts either from Mercury or an after market supplier such as Sierra.

"
 
" Tony,
If I disconnect the f

" Tony,
If I disconnect the fuel line coming from the fuel pump to the carb and pump the bulb, yes,
fuel flows. I am replacing the bulb tonight and
checking the tank and vent on the tank. What is Sierra, is there a website or a phone #? What weight of and type of gasket material for the carbs? What type of carb cleaner? I have a can of Mercury Carb Cleaner, is this good enough and I have an air compressor.
Thanks,
Dave "
 
" Dave,

I don't think t

" Dave,

I don't think there is a problem with the valve, I would concentrate on the carbs.

You can take them apart and let the parts soak in a bath of gasoline or paint thinner. Blow out all passages and jets.

You could order parts from any Mercury dealer. You could do this online at www.mercurymarine.com also, and they will be sent through the nearest dealer in your area.

You could try www.seilermarine.com for after market carb kits. I'm not sure if they are available for your engine, but it pays to look into it because these kits might be less expensive.

Tony "
 
" I had a 1986 Mercury inline

" I had a 1986 Mercury inline 6 115 HP with about the same problem. If you have distributor-less ignition, the high side of your stator might have went bad like mine did. You can check this out with a ohm meter. If you need help with readings let me know I have a manual with the chart. "
 
Re: " I have a 1981 inline 6, 115

I have similar problem. Mine idles great all the way up to 3500 then it starts studdering. Compression is good. Spark is good. Fuel is good. Timing is at 20 when I’m cranking with throttles open.
 
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