620 carb removal question

First if it is leaking gas out around the bowl, carburetor body interface, there is a good possibility you have more problems than just leaking gas. The gas level shouldn't be that high in the bowl. Check your float level. The gasket provides an air tight seal for the carburetor to work properly. If you are getting a gas leak at that level the float needs adjusting. Secondly I agree it would be better to work the problem with the carburetor off the tractor and the removal of 8 bolts and diconnecting the throttle and choke will allow you to remove the carburetor out the side and bottom w/o removal of any more parts. There are two gaskets, one between the intake side of the carburetor ot the air intake tube and the other between the carburetor and the manifold. The latter is the most critical and must have an air tight seal. I would throughly clean the two surfaces of the carburetor and the two surfaces of the intake tube and manifold so that when new gaskets are installed they will provide the good seal you need.

Now, the carburetor bowl to body seal issue. Once you remove the carburetor, remove the nut and remove the bowl. Then check the groove that the bowl gasket fits into. Is it completely clean and smooth? if not that will need to be taken care of before there is any chance of success. Then verify that the top of the bowl surface is not damaged or distorted. Once that is properly taken care of then I strongly recommend that you obtain gaskets from Roberts Carburetor Repair in Spencer, IA. Their gaskets are a bit softer and thicker than JD's and tend to seal better on the older, less true surfaces.

The bowl gasket should fit right in the slot on the carburetor body and stay in place while you put the bowl back on. If not there is something still wrong with the carburetor body slot.

Another thing to check is to see if the bowl has been warped in the nut area. If it has been over tightened at some time, the bottom of the bowl will be pressed in too far and then the bowl will never seat properly with the bowl/carburetor gasket. This can be checked with some experimenting.

Now there are two more areas her that can properly give you gas leaks if not properly installed otr are bad. there is a washer gasket that goes onto the threaded part of the carburetor before the bowl goes on and then the nut. If this gasket is bad then you will get leaks out of the bottom of the bowl. Then there is one more "O" ring gasket on the screw driver slotted load adjustment nozzle. The "O" ring mounts in a radial slot on the nozzle and if it is damaged or split, it too will allow gas to leak out of the bottom of the carburetor.

Hopefully, I have covered all areas of where the carburetor can leak gas.

Below is a link to Roberts carburetor Repair. Hope this helps.

• Roberts Carburetor Repair

With the carburetor inverted, a rule of thumb I use on carburetor floats is that it is parallel with the surface of the carburetor body where the bowl mates. This has not failed me yet. JD publishes a Carburetor manual which I don't have handy at the moment and it would give the exact dimension to measure for correct float height. But just by looking at the float in the closed position one can pretty well tell where it is supposed to be. Just be very careful not to damage the needle and seat while you are messing with the float.

Roberts Carburetor Repair sells an inexpenive clear tubing and fitting arrangement, which are also easy to fabricate, that will allow you to see where the gas level is and how the float is working with the carburetor fully assembled.

Good luck.