Replace Carb Drain Screws

Hi all!

I have an '83 XJ 550 Maxim.

I'm wanting to replace my carb drain screws. They aren't stuck, but the heads are very nearly stripped so I thought I should proactively replace them now. Looked up the parts on Babbits and bought 4 replacements with o-rings.
1. Can I replace them without removing the carbs? Just, unscrew them and screw in the new ones (with rings)?
2. I should have the petcock set to ON when I do it? Do I need to disconnect the fuel line first?

 

Depends how fast you are. If you place a rag under the carb and have the new drain plug ready, you can unscrew the old one and quickly insert the new one without losing much fuel, however, now would be a good time to actually drain the carb bowls and remove any debris that may be in there. Put one end of a rubber hose on the nipple of the bowl and and the other end in a can or bottle, open the drain screw. Let it drain till clear. Remove old drain plug and install new one.

 

you could use a nipple and hose and drain bowls with petcock set to on . then replace the drain screws.
your carbs do not have a drain nipple.

 

So if I leave the fuel line connected and set the petcock to on, when I remove the drain screw - only what's in the bowl will come out?

 

If you hold the line up in the air, you can do the switch, then you only lose just the little bit in the tubing, too

 

Correct.

 

Provided the petcock is functioning properly, it should not flow gas in ON or RES with the motor off.

 

I replaced mine without removing the carbs. Only lost what was in the bowl, per Bigfitz' comments about working petcock.

I replaced with the one's sold by XJ4ever that are hex screws (at least I think that is where I got them, not sure where else I would have bought them...)

I also got the plugs with hose attachments for the drain hole.