TW200 Forum banner

1 - 18 of 18 Posts

·
Registered
Joined
·
60 Posts
Discussion Starter #1 (Edited)
Hi everybody, here I'm again trying to get some help/advice.
I was doing a major carburetor clean up and I have decide to replace the mixture screw to be sure everything is clean and good working condition.
It was set approx. 2 1/4 turns out so I started to unscrew it out and just 3 or 3 1/5 it began to get really hard, I know there isn't other way out so I had no other option to use all my hand power for a few turns until the last few threats it became smooth again and it came out.
Now is when I have the problem, the new screw or even the used one refuses to go back all the way in. It starts nice and smooth but it gets to the point that doesn't want to go in anymore, I'm destroying the head with the screwdriver and I know that's is not bottoming in, the head is almost flush with the carburetor edge so if I open 2 1/2 turns out from there the head sticks out. Both screw are identical length!
Does anyone had this situation?? The carburetor thread looks fine to me. I put a drop of oil and it didn't help at all. When I pulled it out I saw that the O ring got smashed so I don't get what's going on. I will really appreciate if anyone has a suggestion to put that little bugger back in place.
Thanks a lot
Daveed
 

·
Registered
Joined
·
19,587 Posts
I would carfully inspect both threads for any damage or debris before very carefully trying to chase both sets with correct tap and die. Confirm everything is clean since it sounds like the old screw had to plow through something fouling the female threads. Smashed O-ring on the new mixture screw hints of some remaining obstruction like aluminum shaved from the female threads when the original mixture screw was forcedly removed.
 

·
Registered
Joined
·
60 Posts
Discussion Starter #6
The hole is clean. I think Fred has the right answer though the problem i don't know how to clean the female/carburetor thread. I guess I will have to find the way to tap it.
 

·
Registered
Joined
·
19,587 Posts
Problem is an un-modified tap will likely bottom out before cleanng up all the threads, plus may generate it's own shavings that will also need to be removed. May have to cut off some of the tap's tapered tip. Perhaps just a normal straight cut bolt of the right pitch carefully screwed in could locate, if not improve, the problem area if it is in the female threads.
A demtal pick might also be able to chase down the threads to identify any irregularity and possibly clean up threads. Good luck, a frustrating dilemma.
 

·
Registered
Joined
·
60 Posts
Discussion Starter #8
I'm back on business Fred!!
I couldn't find any bolt of the same thread pitch so I had to be creative. Using a Camelback hose cleaning brush and air compressor, patiently I cleaned up the carburetor thread. It goes all the way in pretty smooth , the only thing is when it passes the 2 1/2 turns out gets kind of loose, I don't think should be a major issue or I will have to re install a plug so I don't mess with it any more!!!!!
Thanks
 

·
Super Moderator
Joined
·
4,882 Posts
Don't know if you guys have "PTFE" tape over there - solves a few problems keeping loose threads in place ......
 

·
Registered
Joined
·
60 Posts
Discussion Starter #13
You are right elime. For now I just put a small piece of chewing gum covered with a tiny circle of duck tape to avoid vibrations. If I have to adjust again all I need to do is pull it out.
I will buy a new screw with new O ring hoping that will work like it used to.
Thanks
 

·
Registered
Joined
·
2,663 Posts
I'm thinking the original problem might have been a screwdriver a bit too wide for the purpose, dragging across the internal threads of the carb. That would explain why it went easy for a few turns when removing it, then got into the threads damaged by the screwdriver. My "carb adjusting" screwdriver is slightly smaller than the ID of the pilot screw hole and has the sharp corners on the side of the blade rounded to prevent this. Just a thought.
 

·
Registered
Joined
·
60 Posts
Discussion Starter #16
Using wrong screw driver could definitely be the reason. When I bought the bike I didn't have the one I'm using now. I remember struggling a bit with it.
For now Fred I'm using mint flavor but is kind of soft, I might have to find a thicker one even if the taste is bad haha!! but I'm planning on replacing the screw shortly so it will save me from going thru a chewing test.
 

·
Registered
Joined
·
8,356 Posts
I doubt the screw will move on it's own once you get it adjusted right. I think if I had this issue I would employ the use of a very light coat of loctite thread locker, the non permanent type. Just be careful to only coat the bottom threads so none of the loctite gets on the tip.

GaryL
 
1 - 18 of 18 Posts
Top