pilot mix screws not bottoming out

just got the replacement idle/pilot mix screws i ordered from chacal. Unfortunately, only 1 out of the 4 will "bottom out." the rest will screw in about half way then get almost impossible to turn. I'm using anti seize and penetrating oil to get them to turn but no luck.

used the screw that would bottom out in each of the other holes, but same result as other screws: half way down the screw would stop turning. the threads in the hole LOOK fine and the screws are new, but looks can be deceiving.

does any one know why this would be happening, other than buggered threads? does anyone know what size thread chaser to use on 81 xj 650 carbs to clean up the threads? these are the coarse thread screws, not the ultra fine ones from later models.

 

Not sure if these have little gaskets that are in with the screw. But I've had that happen on my xs650.

 

were u able to fix it? there are o-rings in there, but they shouldn't affect this, should they? they're supposed to be there....

 

Len (chacal ) has the proper tap for those threads. I would just order one and get it cleaned out. I'm sure you could resell it once your done. Or better yet see if someone can mail you theirs and you could return it. Are your threads course or fine?

 

coarse. i'd prefer to buy one from ace or something and return it for a full refund, so I'll ask Len if he could just tell me the specs on that tap.

thx for the help.

 

yes the o-rings are supposed to be in there. but if it is catty wampus they could cause the screw to jam up. or if there is one on the screw and one in the hole already then the screw def won't go all the way down. I know i may be stating some obvious stuff but it is the little things that kill.