1952-54 Evinrude 3hp Lightwin Carb Problems

[lakedawgs]

I received a 1952-54 Evinrude Lightwin 3hp in great shape. I replaced the coils, points, condensors, plugs, impeller, lower seals and rebuilt the carb.
The motor will start witht the control lever in the start position but will die after 30-60 seconds. I have removed, dis-assembled, cleaned and re-installed the carb 3X now, it is seemingly spotless! The fuel line/fuel filter has been removed and is very clean. I have removed the freeze plug on top of the carb and blow it out. I have checked the reed valve and its very clean. When running and I adjust the slow speed valve an 1/8th of a turn it responds, but still dies.
I am at the end of my rope on this one. I do not have a lot of $ to put in to this but will not give up at this point. I know I am missing something but cannot figure out what it is. 20 years ago I rebuilt a few VW engines and carbs, but this is the first boat/small motor I have messed with.
I will end up taking it to a boat motor repair shop, but it is very frustrating as this does not seem that hard. I have been going over the factory owners manual and a rebuild guide I downloaded to see if a light bulb goes off in my head.
I am really just reaching by posting here, but my lurking has shown this board holds a ton of knowledge.
Any suggestions appreicated.
Matt Anderson

 

[Paul Moir]

Re: 1952-54 Evinrude 3hp Lightwin Carb Problems

30-60 seconds should not be a carb problem. Are you sure you've got adequate flow to the carburetor? It can be tricky sometimes with the gravity fed system. Just pull the fuel line off the carb and open the fuel petcock. If it just drips, you've found the trouble.

The filter on that outboard which is up inside the tank clogs very easily. I have never successfully cleaned one despite many varied attempts.

 

[lakedawgs]

Re: 1952-54 Evinrude 3hp Lightwin Carb Problems

When I started to clean up the motor I removed the fuel filter/fuel line from the tank and soaked it in carb clearner and could see light through it all the way around. I recent wanted to drain the tank and removed it from the motor and set it on my bench and opened the petcock and got a nice steady flow, so I feel pretty good about that being clean.
Thanks and keep the questions coming!
Matt Anderson

 

[Scaaty]

Re: 1952-54 Evinrude 3hp Lightwin Carb Problems

Maybe a float problem? Check the level, in fact raise it a touch

 

[Paul Moir]

Re: 1952-54 Evinrude 3hp Lightwin Carb Problems


How long does it take to come around after it runs it's 30-60?

That's too soon to be an overheat, and it should be obvious that it's cooling properly. A little water dripped on the cylinder head is a good test - it should steam away but not sizzle.

When you rebuilt the carb, the carb kit probably came with a rubber tipped needle right? Did you use the tiny spring that holds the rubber tipped needle to the float?

I would check the flow right at the carb unless you're certain that little copper fuel line isn't clogged too.

 

[lakedawgs]

Re: 1952-54 Evinrude 3hp Lightwin Carb Problems

I'm certain the fuel drains well from the fuel line. I drained a tank of gas from there and it flows steady. The needle is not rubber tipped, all steel. How would you test flow, someone mentioned removing the drain screw at the bottom of the carb, said it should keep flowing even when the carb float bowl is empty. Does that sound right?
After running it a few times I can touch the cylinder head, its hot, but not remove fingerprints hot. The crankcase behind the cylinder head is hot, but I can leave my hand on it. I can restart the motor all I want after it dies.
Thanks much,
Matt Anderson

 

[Paul Moir]

Re: 1952-54 Evinrude 3hp Lightwin Carb Problems

That's a fine way to test for fuel flow.

When you restart, do you have to use the choke again?

 

[lakedawgs]

Re: 1952-54 Evinrude 3hp Lightwin Carb Problems

When you restart, do you have to use the choke again?
[/quote]

No, I do not have to use the choke on a restart. I have also started from cold without the choke.

 

[CFronzek]

Re: 1952-54 Evinrude 3hp Lightwin Carb Problems

Do these motors still have the cork floats? If it does they may not float any more.
The fix for cork floats has been mentioned here but, I'm not familiar with it.
If this thing starts without the choke it may suffer from a float bowl running over with gas. Another sign the float may be sunk.

 

[Paul Moir]

Re: 1952-54 Evinrude 3hp Lightwin Carb Problems

Ah, ok that's a good clue. Somehow the engine is probably running very rich then. It's very difficult to start a 3hp cold without the choke.

Where are the mix control knobs at right now? The initial settings are 1-1/4 turn out on the low speed (top) and 3/4 of a turn out on the high speed, but usually you end up around 1 turn out on the low speed and 3/8th of a turn out on the high speed from lightly seated.

The only other possibilities are a leaking needle & seat (carb should flood fuel if this is happening) and a leaky main jet gasket. If the main jet boss gasket is not brand new, it's a likely culprit. That's the one right above the screw driver here:

 

[lakedawgs]

Re: 1952-54 Evinrude 3hp Lightwin Carb Problems

It is a cork float, it looks good, but what does that mean? A new one did not come with my carb kit, are these cork floats replaceable, or it there a workaround?
The boss gasket you show in your pic is new from the carb kit.
The initial settings on the needles are exaclty as you mention above, 1 1/4 & 3/4.
Thanks,
Matt Anderson

 

[Scaaty]

Re: 1952-54 Evinrude 3hp Lightwin Carb Problems

Do this....When the motor starts to quit, hit full throttle until it dies. Pull the plugs. Wet or dry? Then we can go from there. This will tell if gas or spark issue

 

[lakedawgs]

Re: 1952-54 Evinrude 3hp Lightwin Carb Problems

Scaaty, I fired it up after work and started to ramp up the throttle until it died. The motor RPMs increased, but not as much as I thought it should, then it died. I did not check the spark plugs, I will do that again tonight and check them.

I removed the drain screw from the bottom of the carb. The carb drained the float bowl and then stopped, almost a drip but not really. I did have the fuel line valve open and the pressure valve on the gas tank lid was open. I only had a quart or less of fuel in the tank, would that matter, I would think not.
Question, how does the fuel 'pump' to the carb? Is it strictly gravity? If so then it should have kept flowing from the drain hole in the bottom of the carb, maybe not a stream but at least a good drip, is that correct? What exactly does the reed do? Sorry to ask so many questions, but this problem has made me really want to understand this simple little carb, AND GET MY DARN MOTOR GOIN!
Thanks much,
Matt Anderson

 

[Xcusme]

Re: 1952-54 Evinrude 3hp Lightwin Carb Problems

Matt, It's a simple gravity fed system. If the carb drain is open, the fuel drains, the float drops, the needle valve is then open, fuel should flow from tank freely through carb and out drain plug. If the flow stops when you open carb bowl drain, try rapping on side of carb body. Does the flow resume?? If it does, you've got a sticking float needle.
On that little popper, you should be able to run longer than 60 seconds on a full bowl of fuel.

As Paul states, starting without the choke , when cold, points to a flooding condition. Back to that Boss gasket. If it leaks, fuel will be drawn into the motor at idle speed and flood the motor. It would be very hard to get her to idle smoothly. One tip off is when you replaced the botton half of the carb body. The boss gasket will hold both carb halves apart slightly. The carb bowl screws will then compress the boss gasket affecting a good seal to the high speed needle circuit. If the carb bodys fit together with no slight gap,this would point to a compressed boss gasket and a possible point of an internal leak just mentioned. During the carb rebuild, did you replace the low speed and high speed needle packings??

 

[lakedawgs]

Re: 1952-54 Evinrude 3hp Lightwin Carb Problems

try rapping on side of carb body. Does the flow resume?? If it does, you've got a sticking float needle.

Interesting, I have not tried that, I will

One tip off is when you replaced the botton half of the carb body. The boss gasket will hold both carb halves apart slightly. The carb bowl screws will then compress the boss gasket affecting a good seal to the high speed needle circuit.

This too is interesting as I have wondered in the back of my mind if I was using the correct gasket from the carb kit. From your description above, I am using the correct boss gasket.

During the carb rebuild, did you replace the low speed and high speed needle packings??

This was confusing during the rebuild. There was no differentiation in the 'gasket' and 'packing', they were the same 'red' gaskets. I do not get leaks from the needles unless unscrewed a great deal.

I noticed today that when I have it running a couple of times that there is a drop or two of fuel coming from between the carb and the silencer, this has to tell you something? Any ideas?
Thanks much,
Matt Anderson

 

[lakedawgs]

Re: 1952-54 Evinrude 3hp Lightwin Carb Problems - XCUSME

Re: 1952-54 Evinrude 3hp Lightwin Carb Problems - XCUSME

try rapping on side of carb body. Does the flow resume?? If it does, you've got a sticking float needle.

Interesting, I have not tried that, I will

I just went out and removed the drain plug in the bottom, fuel drained out steady and then stopped. I waited for 2 or 3 minutes and only a drop or two came out. I lightly tapped the carb with a screwdriver and the fuel started to flow steady again. My needle is obviously sticking. I used the new spring/clip that came with the needle and valve with the kit. How do I remedy this one?
Thanks,
Matt Anderson

 

[Xcusme]

Re: 1952-54 Evinrude 3hp Lightwin Carb Problems

Matt,
I kinnda thought we were heading in that direction. Remove the carb (again) and remove the float cross pin (hinge pin) and remove the needle and spring wire. NOTE which side of the float arm the wire is on. Re-insert the float and hinge pin. Gently raise and lower float to be sure the float isn't binding on the hinge pin. It has to pivot with very little upward pressure.
Remove the float and install needle and wire on float arm. This time , move the wire to the opposite side of the float arm. Install float (with needle and wire) , insert hinge pin.
Gently raise and lower float. Needle should not bind. Don't apply too much upward pressure to the float. Reassemble carb and with carb upside down, blow into flue line fitting. Air should NOT pass into carb. Invert carb to normal position and blow into fuel inlet again, air SHOULD pass into carb.

On one problem carb I had, I used a Q-Tip and fine rubbing compound to burnish the needle tube and seat. Be sure to spray all extra compound from the tube , with carb cleaner ,when you're done. To test, just drop needle into the tube and invert the carb. The needle should fall out effortlessly each time. Assemble and test as above .

 

[Scaaty]

Re: 1952-54 Evinrude 3hp Lightwin Carb Problems

" fired it up after work and started to ramp up the throttle until it died. The motor RPMs increased, but not as much as I thought it should, then it died. I did not check the spark plugs, I will do that again tonight and check them."

You can't wait to see if the plugs are wet or not. You must run it until it dies then look for a wet or dry plug right away!. but you definitely have a float prob

 

[lakedawgs]

Re: 1952-54 Evinrude 3hp Lightwin Carb Problems

You can't wait to see if the plugs are wet or not. You must run it until it dies then look for a wet or dry plug right away!. but you definitely have a float prob

I'm with you, I will fire it up tonight and remove a plug.
Matt Anderson

 

[lakedawgs]

Re: 1952-54 Evinrude 3hp Lightwin Carb Problems

Matt,
I kinnda thought we were heading in that direction. Remove the carb (again) and remove the float cross pin (hinge pin) and remove the needle and spring wire. NOTE which side of the float arm the wire is on. Re-insert the float and hinge pin. Gently raise and lower float to be sure the float isn't binding on the hinge pin. It has to pivot with very little upward pressure.
Remove the float and install needle and wire on float arm. This time , move the wire to the opposite side of the float arm. Install float (with needle and wire) , insert hinge pin.
Gently raise and lower float. Needle should not bind. Don't apply too much upward pressure to the float. Reassemble carb and with carb upside down, blow into flue line fitting. Air should NOT pass into carb. Invert carb to normal position and blow into fuel inlet again, air SHOULD pass into carb.

On one problem carb I had, I used a Q-Tip and fine rubbing compound to burnish the needle tube and seat. Be sure to spray all extra compound from the tube , with carb cleaner ,when you're done. To test, just drop needle into the tube and invert the carb. The needle should fall out effortlessly each time. Assemble and test as above .

I will start to tear it down again tonight after I run it and check the plugs for wet fuel.
Thanks for the idea,
Matt Anderson