Carburetor issue

[jpatti75]

I was trying to fire up my 1948 Mercury KE4 today, and I am sure I have a carburetor issue and was hoping to get some pointers. When I opened up the fuel petcock, there was fuel clearly getting to the carburetor, but the motor didn’t want to start at all (not even a pop). After giving my shoulder a work out, I decided to pull the plugs to see if the motor was somehow flooded. Well, the situation was quite the opposite, the plugs were completely dry and looked just like they did coming out of the box. So, no fuel is getting to the plugs to start….hmmmm.

Now, I rebuilt the carburetor and the ignition is completely rebuilt, too. Given that the plugs are bone dry and I had a couple drips coming from the carburetor, where should I start on the carb? There were a couple small drips coming from the venturi, but there were also a couple drips coming from here:

I broke down this carburetor, cleaned everything, and blow out every passage with compressed air, but I musta done something wrong. Can’t remember if I put in a new plastic float or sealed a cork float…I think it was the former.

Thanks,
JP

[frankr]

I’m going to resist the urge to suggest reeds. But do you get the characteristic 2-stroke "plop-plop" sound when spinning it with plugs out?

[billw]

Yeah, I would listen for the "plop, plop," too. But also, be sure that the choke closes all the way and sits tightly against the front of the carb. For such a simple choke system, they will not work right, if even just a bit out of whack. When working right, those are two-pull motors. The very first pull will flood the engine, the second will clear the flood and start it.

Long live American manufacturing!

[jpatti75]

Thanks, gents…I’ll pull the plugs and give a listen. Should have thought about the reeds. I think the choke is doing its job, but I will give that another check, too. (This was reportedly another runner …I’m such a sucker!)

JP

[Tubs]

How far open is your high speed mixture needle?

A "Boathouse Repair" is one that done without having tools or the skills to do it properly.

[jpatti75]

Tubs,

I went of the guidance in the Merc Master Manual, which said 1 turn out for high speed, 1.5 turns out for idle. It was general guidance for the gravity feed carbs, and not necessarily specific to the KE4. What did you do on the one you just finished up?

JP

[frankr]

Not a merc guy, but I’m thinking 3/4 turn on idle (air) needle. But not likely that is the problem anyway.

[Tubs]

quote jpatti75:

Tubs,

I went of the guidance in the Merc Master Manual, which said 1 turn out for high speed, 1.5 turns out for idle. It was general guidance for the gravity feed carbs, and not necessarily specific to the KE4. What did you do on the one you just finished up?

A "Boathouse Repair" is one that done without having tools or the skills to do it properly.

• This reply was modified 6 years, 6 months ago by Tubs.
• This reply was modified 4 years, 2 months ago by Tubs.

[jpatti75]

Thanks for the input, gents. I’ll report back once I do some troubleshooting.

[20mercman]

Did you by chance squirt some gas in the plugs when they were out? If you give it a little prime, it should pop even if the carburetor is an issue. If it runs, then check your float and needle assembly. Very easy to remove the top of the carb and see if it is full of fuel. Is the choke plate tight against the face of the carburetor throat? I just had a 1972 200 that I built. I was having hard starting cold, I had inadvertently placed a thin washer behind the choke plate, and that was keeping the plate from seating against the carburetor. The AJ-23A on the KE-4 should fit pretty tight. They can be easily bent and not sit flat. Mercury’s like fuel when starting!

The first thing I suggested will let you know a lot. See if it runs first. If so, then it is most likely a choke circuit issue. The idle screw is an air valve, so the farther out the leaner it will be.

Keep us posted!

Steve

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