M37 Flooding Bad

[grimlock97]

ok, I am still trying to get my 53 to fire up, I ordered new plugs and wires and now I am getting fire to all cylinders, but the carb is flooding badly, there was even gas in my oil pan, so I changed the oil and filter this morning, I am pretty sure it's not my needle seat on the carb intake for several reasons, I have cleaned it multiple times, I have tested the float and needle seat with the carb full of fuel and blowing air into the seat and no air will pass. I finally completely disconnected the fuel and filled just the bowl of the carb with gas, so the only gas in the system is in the carburetor bowl, I tried to turn it over, and pulled the carb off again and sho nuff, the intake is slam full of gas, the float only controls fuel getting into the carburetor correct, so the float should have no bearing on how much fuel is getting into the intake, so anyone have any ideas what would cause the flooding? thanks guys,

 

[swiss]

2 items I can think of

1.) The float level could be set to high and fuel leaking into the intake. (I have not taken this carb apart so not sure the components on this particular carb) Since you tested with only the bowl filled then you should be able to rule out this issue. That only leaves the next.

2.) The bowl could be cracked and the fuel leaking into the intake. Take the carb off and fill the bowl with fuel and find the leak.

No the float only controls the shut off of fuel into the carb bowl.

 

[grimlock97]

I took the carb off and have had it sitting on the fender for the past 30 minutes or so to see if it leaks just sitting there, and there is no fuel underneath the carb from sitting, so i'm guessing there is no crack, the fuel line is completely disconnected, so no more fuel should be getting in the carb bowl, the float is set at 5/64th ish, but I have ruled the needle seat out. the carb is about 3/4 full of fuel right now, how many turns out should the idle screw be turned? is it possible that a wrong idle adjustment is allowing fuel to pass through?

 

[longshot2171]

Check the fuel pump to see if the diaphragms are ruptured. You might be pumping/leaking fuel through the vacuum side into the intake manifold.

 

[grimlock97]

please forgive my ignorance, but it seems the fuel is leaking through the two holes in the middle of the carburetor, if that makes sense, here is a picture of where it seems to be dripping slowly from.

 

[swiss]

You can try 3/4 of a turn out on the adjustment as a starting point. I do not think that is your problem. Are all the jets in place in the carb?

Fuel cannot normally leak through a carb. It is pulled in by the engine vacuum through the main jets and is mixed with air to get your air fuel ration and emulsified fuel.

 

[grimlock97]

Check the fuel pump to see if the diaphragms are ruptured. You might be pumping/leaking fuel through the vacuum side into the intake manifold.

The vacuums are disconnected for trouble shooting, the elbow is not connected,

 

[poppop]

I am not familiar with this carb but most carbs have a bowl vent. If this vent is plugged then rising tempertures or shaking the carb will pressurize the bowl and force fuel out. It also creates a problem with the engines sucking gas from the bowl because it is pulling against a vaccume.

 

[pwrwagonfire]

Correct me if I'm wrong...but doesn't fuel in the oil mean your rings are bad?

 

[grimlock97]

I'm not a hundred percent sure on that, usually yes, but i know i have good compression on all cylinders so i wouldn't think it is the rings in this case, i got to thinking about it a little bit and what longshot stated above makes sense, i have the vents disconnected for troubleshooting, not the vacuum coming from the fuel pump, sense this is a dual action pump it could be pushing fuel in through the vacuum side of the pump, i believe, i'm going to take the pump off today and check it out, the amount of fuel that is in the intake as soon as i turn it over, i don't think the carb could put that much fuel in the intake that fast. I'm trying to get this running before the 4th of july parade so i can put my M939 and the M37 in it.

 

[poppop]

If fuel puddles in the intake enough and an intake valve is open then gas will run into that cylinder. It then runs past the rings into the crankcase. I have never heard of gas going past bad rings if the engine still runs. Fuel pump most likely is the problem. If the diaphram has a hole in it it can still work but gas will leak through the hole into the crankcase.

 

[misupratwin]

This may or may not help you, but I had the same problem with my truck ,good compression , my fuel was in a upside down pop bottle with a hose to the carb, I would get fuel puddling in the intake gas in the oil. It would run off either if I cleared the engine of fuel. In the end I pulled the engine and found ever top ring was broke in half. Tim

 

[grimlock97]

Thanks for the info, I just can't get her to fire up, I disconnected the vacuum line and turned it over a few times with the carb just sitting on the intake and it didn't pour gas out of the vacuum line or anything, I went ahead and pulled all the plugs and put new points and condenser in and set cylinder #1 on TEC and gapped the points, and yes I made sure it was the compression stroke and it was sparki just like before, all 6 plugs are sparking, I just had to rule that out but the intake is still damp with raw fuel, none of my plugs are wet at all, I don't know where to.check next