Carb Dripping from Drain

Having a problem with my carb. It is a TSX-33 on a 9N. The carb was rebuilt and I'm now trying it out. I'm getting excess gas in the chamber with the venturi and choke plate and it's coming out the 'weep' hole - I got a little when I ran it a week ago; now I collected what I estimate is about 3 ounces of gas that dripped out this time. There was so much that when I took the carb off after letting it finish dripping, the inside of the air tube was wet and so was the choke plate. The bowl had gas in it as expected. I believe the needle valve and seat are ok since they are brand new parts. New gaskets, seals - your standard carb rebuild. The main jet, float, etc. are adjusted as per the book. The tractor is running OK also. The first 2 times I ran it recently (10-30 minutes each) had no problems, the third time I had a little dripping but nothing like this last time - and I had only run the tractor 5 minutes. I understand maybe a few drops here and there - but ounces? I also shut off the gas at the tank when not in use. Thoughts?

thanks in advance....

Pull the carb off.

Put a bucket under the fuel line while you are working on the carb to insure that the sediment bowl cut off is working.

Did you replace the gasket under the float valve seat?

Make sure the needle valve moves freely.

Tighten down the needle valve seat.

Did you test the float for leaks?

Re-set it; can't recall off the top of my head, but I think the drop is 1/4". Insure that the float doesn't hang up on the side of the bowl.
75 Tips

Check your air cleaner (look up inside it, not just the cup) to make sure it is not partially plugged with dirt. If it is not clear, it is the same as running with the choke on.

Thanks....air cleaner was torn apart and cleaned when the carb was rebuilt so no dirt there....

The sediment bowl cutoff 'weeps' a little and I plan to replace it - but only a little.

The gasket under the float valve seat is new. The needle seems to move OK - just sticks closed very slightly due to the rubber tip. I was able to tighten the valve seat 1/4 turn - could that have been the cause?

The float is empty, was tested and looks to be in good shape. I believe you are correct; I had it set at 1/4".

I will check for float hanging up.

So - it sounds like, from the two replies I got, two main causes of gas getting in here is over-choking and the needle valve/float allowing too much fuel in the bowl?

thanks again....

" I was able to tighten the valve seat 1/4 turn - could that have been the cause?"

Yep.

" over-choking"

That will do it too.

The usual cause of gas dripping out of the carb throat is operator error.

While each N has its own starting sequence, none of them will start well by just yanking out the choke rod & holding it out for 5 or 10 seconds while the engine cranks. This is a gravity fuel system on a low compression engine; it is easily flooded by too much choke.

Try this:

Key on, gas on 2 full turns, clutch in, 3/4 throttle, press the starter button. Let it crank for at least 3 - 4 seconds before you pull the choke rod. Then, don't hold it out for more than 2 or 3 seconds.

If you find out it will not start w/o excessive choking, you have problems.
75 Tips

" The sediment bowl cutoff 'weeps' a little and I plan to replace it"

They are easy to rebuild.

1. Get out all the carb cleaning tools.

2. Pull it down (bowl off, screen out, stem out)

3. Look at the stem; if it really is OEM, it will have graphite packing, just like a faucet. Get some from the hardware store (NOT teflon!) If it’s a newer replacement OEM bowl, it will have O-rings. Same deal; hardware store for replacements

4. Your call on soaking it in carb cleaner; I didn’t, because I use the real caustic stuff and the metal looks like aluminum. So, I sprayed it out w/ canned cleaner.

5. Make sure you get air through both the main and reserve ports.

6. Use your welding tip cleaners if need be, but I’ve never had one clog bad enough that canned cleaner & air wouldn’t open ‘em up.

7. The nut that holds the stem in keeps it from leaking. You need to find the happy medium of “to tight” (the knob won’t turn) or “to loose” (it leaks.

8. Replace the screen and gasket; NO sealer on the gasket. If it’s a cork gasket, soak it in gas first.

9. Use pipe dope as a thread sealer when you put it back in the tank.

10. Put the bowl back on & hand tighten the thumb screw. Turn the gas on & look at the bowl. If it starts to fill the bowl, turn the gas off & start over; it has a leak. You will know it's sealed when gas does not flow into the bowl w/ the engine off. It won't fill with the bowl securely on because the float has closed the needle valve in the carb and there is nowhere for the air in the bowl to escape. (assuming the carb bowl is full) When the engine is started the needle valve will open and the trapped air will escape through the carb vent. If you loosen the bowl, it will fill.....and leak.
75 Tips

Thanks.....looks like I have plenty of things to try.

Like Bruce[Va] said,every one of these machines aree different. On mine,my starting sequence goes like this,winter and summer,and always works[99%]. I have a hand crank and using this,key off,I wedge a twig in the choke knob,opening it fully. I open the throttle a couple of notches,then crank it a few rounds. I then turn on the key,and it starts right up without choke. Then sometimes I have to play with the choke,popping it quickly when it falters. I use the hand crank mostly because I have it,and nostalgia. It used to be on my old '48 Dodge truck and I've used it a few times when the battery was bad or it was really cold. lha