Seafoam?

[Clause]

I was given what I believe to be an 1981 Mercury 2 stroke, 2 cylindar, 4 hp. Apparently otherwise known as the "Gnat."
It has been sitting for at a bare minimum of ten years without being started and I do not know if it were properly put to sleep either.
I've changed the plugs, fed her 50:1 with merc oil, gear lube, and took apart the carb cleaned it up and put it back together, multiple times(understatement). I have the spring in what I believe to be the right place, I'v bent the flap where the pin attaches to the float in order to get it not to leak gas. Maybe I've moved it too much, but my friend said that shouldn't make much difference.
The engine will start, most of the time. Idles smoothly, fairly consistantly anyway. The engine will not rev up though. It seems as if it may go for it at the start position, but fails to do much past there. I'm wondering if anyone has a suggestions. Also, I'm wondering if anyone thinks some seafoam in the gas and sprayed into the intake would be a good or bad idea.(helped my honda accord)
Thanks for any responses, including those influencing me to hang the motor as a punching bag. I myself have had words with this engine and gather many others have given it the finger as well!

 

[j_martin]

Re: Seafoam?

If it starts and idles fairly well, it is somewhat healthy. At least it should run for now.

Either timing isn't advancing, spark isn't strong enough (for various reasons), the throttle valves aren't opening, or it isn't getting gas.

Not much else could be wrong.

They don't seem to listen when you talk to them.

hope it helps
John

 

[mercuryman48]

Re: Seafoam?

check condition of fuel lines and fuel pump output

 

[kennyboater]

Re: Seafoam?

i had almost the exact same problem, i cleaned the carb but still had same problem. get a manual and actually do a rebuild gasket kit. and i found the second time tearing the carb apart that i actuall had a small crack in my float letting gas into it causing the float not to move correctly
we will see i it opens up tomorrow on the lake as it idels great

 

[thefairlaneman]

Re: Seafoam?

I would check the plugs and see how they look. Check the wires with a spark tester(easy to make) I understand the timing/spark advance/dwell whatever you want to call it is critical to higher speed performance as well as the engines temp. If you try to compensate for incorrect timeing by adjusting the carbs too much and get a too lean mixture it is bad for the engines cylinders.Im just a novice the old school guys know 10 times more

 

[ovrrdrive]

Re: Seafoam?

If your floats are adjusted incorrectly it can cause the motor to starve for fuel... I'd look there and at the main jet and make sure it isn't clogged. Buy the rebuild kit as mentioned and follow the directions and I bet you'll be fine.

 

[j_martin]

Re: Seafoam?

I just looked at the other thread you have started on "the knat". After viewing that, I perceive that if you want this thing to run, you're going to have to get serious about it, like get the right tools and a service manual.

When you just change things on an outboard, like timing without a timing light, and float levels without instructions, you usually just add to the problems. Multiple faults are hard to find if you do things right, and usually impossible if you're just messing around.

hope it helps
John

 

[Clause]

Re: Seafoam?

Proper tools, Agreed! Plugs wet. I just had the carb apart and readjusted the flap on the float. My adjustment made no difference, I did measure, but I'm still confused on exactly where I should have 5/64 - 7/64. What I did was measure the highest part of the float (when in up position) from where the needle enters the hole. That being said, my friend is coming over with a timing light around 4 o'clock today.

I'm thinking it's possible I should clean the one way valve on the bottom end of the motor(breather), as per the gent above suggesting crank seals/ high pressure in the crank case occurs with higher RPM's

 

[jimg984]

Re: Seafoam?

you need to do what john suggested,,,, you are just fishing around,,, fishing is for the lake,,,,,, that is you realy wanna make that thing work