Pilot air screw loosens but won't come out

[matt_gs450]

Hi All,

I'm in the middle of a carb rebuild for my 81 450T. I have everything disassembled except the pilot air screws. For some reason they won't come out. They tighten and loosen, and I can hear the spring compressing as I tighten them. But when fully loose, they will not come out of the carb body.

I have a spare parts set of carbs, and the screws on that set come out easily. My hypothesis is that someone replaced the original o-rings with a fatter set and that is why the screws won't come out.

Does anyone have a trick I can try? Will carb cleaning fluid dissolve the o-ring?

Thanks,
Matt

[chef1366]

Screw them in till lightly seated and take some PB Blaster and spray in there and sit for a couple of days.

[matt_gs450]

I have gumout carb spray. Is that comparable to PB blaster?

[chef1366]

I believe the carb cleaner will evaporate while the PB Blaster will sit in there and do it's job.

[matt_gs450]

OK. I went and bought some PB. It looks like the business end of it is naptha. That's an ingredient that's not in the carb cleaner. I'll update in a couple of days.

Thanks,
Matt

[BadBillyB]

Remove the pilot jet and blow compressed air into the hole they came out of. They may come out real fast so keep a rag around the carb just in case.....BadBillyB

[matt_gs450]

OK. They're both out. I let the PB sit in there for a while, worked the screws back and forth, put more PB in, repeated. I did that three times and then started banging the opposite side of the carb with a wooden mallet. The right screw came out immediately.

The left one was more stubborn and what ended up happening was the o-ring disintegrated, and I was able to unscrew the pilot screw completely as its threads caught onto the bits of the o-ring.

Thanks for the PB tip, Chef.

-Matt

[chef1366]

I'm only relaying what I have learned here. Glad it worked for you.