TK22 drain screw leak

No eBay APP ID and/or Cert ID defined in Kunena configurationHey everyone
I recently ordered a new carb drain screw for my KZ550C2 to replace one that had a stripped head. I ordered the screw with the part number 92066-1065. This is the link to the part.
I installed it in the carb and turned the petcock to PRI to continue checking my float heights. I got the heights correct on all carbs and then noticed a continuous drip of a small amount of gas from the carb with the new screw. It didn't leak with the old screw. Is the screw I ordered the correct screw for this carb and if so does anyone know how to stop it from leaking?
Thanks

Part number seems correct for the drain screw.

Are both 0'rings present and in good condition?

Did the old 0'rings come completely out of the carb?

Could swap drain screws with one of the other carbs and test for comparative leakage.

Also compare the physical likeness of the new screw with the stripped screw and a screw from one of the other carbs.

Should not need any type of "sealant" on any of the screws.

Perhaps the seat was damaged incident to whatever excessive force was previously used in doing whatever it took to strip the damaged screw. But doesn't explain why the old screw didn't leak. So compare the stripped screw and the new screw with one of the non-leaking screws from one of the other carbs.

Good Fortune!

That is the right part number you bought.
Does it look like the others?
Does it look like the old one?
If you put the old one back in, does it still leak.
It can be leaking from the screw not sealing, or the float level being set too high, or the overflow tube, inside, is cracked (not uncommon).

Looks like Patton beat me to it.

No eBay APP ID and/or Cert ID defined in Kunena configuration

nickleo373 wrote: Hey everyone
I recently ordered a new carb drain screw for my KZ550C2 to replace one that had a stripped head. I ordered the screw with the part number 92066-1065. This is the link to the part.
I installed it in the carb and turned the petcock to PRI to continue checking my float heights. I got the heights correct on all carbs and then noticed a continuous drip of a small amount of gas from the carb with the new screw. It didn't leak with the old screw. Is the screw I ordered the correct screw for this carb and if so does anyone know how to stop it from leaking?
Thanks

I installed it in the carb and turned the petcock to PRI to continue checking my float heights. --- On some carbs, the clear tube test to determine fuel level is performed with the drain screw removed from the carb and the clear tube connected to the drain screw hole. On others, the clear tube test is performed with the drain screw loosened and the clear tube connected to the overflow nipple.

Would double-check source of the leak to assure the leakage is getting past the new drain screw, and not from a float bowl gasket or overflow nipple.

Good Fortune!

Thanks for the replies
I noticed the new screw uses thinner o rings than the original screws (which is strange because it's supposed to be a NOS part). I'll test the screw on different carbs tomorrow to see what happens. I only checked on one of them tonight.
And thanks Patton. I was under the impression that I had to attach a tube to the overflow drains and screw out the drain screws to do the float heights. I'll try it the other way and see if the results change

This illustration depicts a carb that drains through a drain screw hole with the drain screw removed (as opposed to draining though the overflow nipple when the drain screw is "loosened."




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nickleo373 wrote: Thanks for the replies
I noticed the new screw uses thinner o rings than the original screws (which is strange because it's supposed to be a NOS part). I'll test the screw on different carbs tomorrow to see what happens. I only checked on one of them tonight.
And thanks Patton. I was under the impression that I had to attach a tube to the overflow drains and screw out the drain screws to do the float heights. I'll try it the other way and see if the results change

I was under the impression that I had to attach a tube to the overflow drains and screw out the drain screws to do the float heights --- some carb designs do indeed also use the overflow nipple as the drain outlet when the drain screw is "loosened" -- not removed. When the drain screw is "tight," the overflow nipple serves only the overflow function.

Having two o'rings (not just a single o'ring) on the drain screw may indicate that the overflow nipple is doing double duty (i.e., overflow duty when the drain screw is tight, and drain duty when the drain screw is loosened.)

With the double-duty version, it would be correct to perform the clear tube test with the clear tube attached to the overflow nipple and a loosened drain screw.

It's manual-checking time.

Good Fortune1

Here's a link to the manual provided in loudhvx's signature, which covers the clear tube test (aka determining the service fuel level)., .

home.comcast.net/~loudgpz/GPZweb/Mnls/Kz...ase99924_1018_06.pdf

Check out page 161





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Haha thanks Patton. I was hoping I wasn't screwing it up since last May

nickleo373 wrote: ... noticed a continuous drip of a small amount of gas from the carb with the new screw. It didn't leak with the old screw....

Is the drip coming from the drain screw hole (leakage past the tightened drain screw) or is the drip coming from the overflow nipple?

Am thinking the larger 0'ring is supposed to prevent leakage past the drain screw (whether tight or loosened), and that the smaller 0'ring is supposed to prevent fuel from the overflow nipple when the drain screw is tight.

As loudhvx suggested, a cracked overflow tube could explain fuel discharge from the overflow nipple even when the drain screw is tight. Because the fuel is escaping through the crack (not it's usual route with a loosened drain screw).

Good Fortune!

Good Fortune!

Good Fortune!