Float bowl drain screw

Hello,
One on my float bowl air screws is stuck. Any suggestions to loosen with carbs on bike? It is #2carb. Screw head is still not stripped. Thanks

Soak it with Kroil for about 3 days and the bond should loosen. Ed

Be aware that any penetrating oil may destroy the O-ring if your model has one. No big deal and easily replaced once you get the screw out.

Thanks. I've ordered the Kroil. I intend on putting it into a plastic tupperware cup that fits right under the float bowl on the bike to cover the drain screw and leave it for three days as Ed suggests. Two questions, 1. Will it eat through the plastic tupperware and 2. Will it discolour the metal on the float/carb housing if it sits there for that time?

Thanks.

If you are in a hurry or it's really stuck Channel locks on the outside of the head work for more leverage, although you'll want a spare screw to hand if you have to resort to those, it's usually not pretty afterwards. I had to use them on one I had stuck in a spare float bowl I was planning on using using yesterday. If you can get the float bowl screws out and drop the bowl, heat works incredibly well, because whatever alloy they make those parts from expands a lot when heated and it really helps things release. If the bowl is off you can also use your choice of penetrating lubricant from the inside by filling the bowl a little and then let it sit. Some of those plugs end up incredibly tight in the bowl and it seems as if they are cross threaded or really corroded and yet when they come out there's nothing obvious, and they screw back in really easily - weird.

Do the float bowl plugs use an O ring or a rubber washer?. The originals always resemble a long dead, squashed fly and I'm never sure if they were O rings originally, or rubber washers. Same thing on the main jet holders, I presume they are O rings because of the recess, but nothing I've ever taken out still resembles an O ring.

I haven't used it on carbs, but I have used it on the carb holder screws, tach drive screw, and some other places and it did not discolor the aluminum or steel. Ed

You could remove the bowl and let it soak in a larger bowl of Kroil so it can soak in from both sides if the screw.

Thanks for the comments. I've ordered a new screw and o-ring. Hopefully the Kroll will work from the outside of the bowl. If not, taking the bowl off may have to happen. It's #2 carb so doing this with carb on bike would be a little more of a challenge. Any tips? Currently the other carbs are drained and the gas has Stabil in it for the winter.

Removing the bowls with the carbs on the bike is not very difficult if you have the right tool. The images below show what to use; either will work and a small mirror may be helpful first time around. Ed