Xj550 Pilot screw issue.

Hello everyone,
I just joined xjbikes forum. I recently purchased an 82 Maxim XJ550 and it was running great. However the carb boots were cracked. So I got new boots and started replacing them. However since the carbs were off I decided to go through them. Well there is so much varnish and rust maybe that I was shocked it was running at all. With great difficulty I removed the main jets. The pilot jets are frozen . It idled great when it was running.
One of the pilot screws is frozen and broken so there is no grip . I tried drilling the top to see if the drill would catch and remove the screw - but no luck -it started disintegrating into brass powder. I tried the crazy glue trick but I could not get the top of the screw clean enough to stick.
So my question: Should I bother, since it is running? I am afraid the cleaning operations would have changed the metered fuel so the screw may need adjustment. Second can I drill it out? I haven't tried applying heat yet. But even if I removed it what is the part number for the pilot screw? The oem parts catalogs don't mention this part.
Thank you in advance for your help.
-Hananiel

 

You might try purchasing a used set of xj550 carbs on eBay since these are relatively cheap, then replace the bad carb(s) after a full rebuild.

 

I am trying to keep costs down if possible - besides with carbs on ebay, I have had prior experiences where it was in "good condition" and he even threw in extra parts. Well all eight float bowls had their drain plugs screwed and you could tell from the baked on varnish that this person tried to heat and remove them and failed. Anyway for my case, Chacal had the mixture screw set i need and I was able to move the pilot screw with a drill bit. unfortunately this only works going down and not up. so I am going to buy a screw extractor tomorrow and try to get it out. Actually I am pretty sure it will come out. I think I will leave the pilot jets alone for now. Get a few miles out of the bike before I spend anymore money.

 

The pilot screw is out ! phew! I ended up using the tiniest drill bit I had and drilling 3 holes - one in the center and other two on either end. I then used a screw driver , hammer and drill to make a slot. I then used this slot to remove the screw . used plenty of liquid wrench while using super human strength and its out. I like this whole fixing bike thing - you just gotta be stubborner than the stubbornest screw. At some point I guess it will get old.

 

You said a mouth full right there.

 

With the price of a Mikuni piston/diaphragm assembly at something just over $100 no matter where you get it, a spare rack o'carbs is the hot ticket for long-term XJ stewardship. Then depending on the condition of what you end up with, you can rebuild the replacement and swap it or just rob it for parts. They generally go for between $50-$150 on eBay depending on the (claimed) condition.