Hi Fellas, on my ct3 i need to know the screw setting on the carb air screw. can anyone point me in the right direction ? . many thanks.. Jez...

1.5 out from seated. Its only a guide within reason. If you need it out beyond 2 then somethings going on, If you need it in to 1 then also something going on. Try the std 1.5 & let us know please. I should say lightly seated but if its not been turned for years it might need slightly more seating to be sure of where you're counting from, or take it out & oil it & try again. Cant break the tip off as it's a coarse tip on that one, just don't overdo it. Give it a run & a rev out after that & see how it settles.

thanks for your reply. my bike feels like its running with the choke on, so i think it needs more air i will try 1.5 turns and see how it goes . thanks....

    is this some sort of breather pipe ??

Yes

Ok, sounds like its running with choke on 'you say'. So a new can of worms evolving. I guess the choke 'is' off, so Oring that seals the jet setter into the bowl is first thought, then comes all sorts of things, float level 'way high', slide needle on richest notch. Slide needle jet very worn. & i'm permanently stuck on exhaust blockage but better not keep guessing just yet. Maybe pilot jet is not seated in the carb body. Video is good if easy to do.
Also looking at the pic of the carb reminds me that if the air jet to the needle jet is blocked that can be seen in the pic in the lower mouth of carb--that will cause richness as it doesn't let the needle spray the fuel out as it should--"or something like that" emulsify if that word works. Have had one bike '200 twin' where one side was blocked by bits of a crumbling air filter & had me stuffed for quite a while chasing my tail.

I think you could have hit the nail on the head there. I have noticed that the o ring on the end of the needle jet is badly worn possibly 50 years old!! I. will replace it and give the whole thing a good clean. thanks for your help .  

 I think you could have hit the nail on the head there. I have noticed that the o ring on the end of the needle jet is badly worn possibly 50 years old!! I. will replace it and give the whole thing a good clean. thanks for your help .  

is this jet all one piece as i cant seem to find it on google to try and replace it ??

Go to the CMSNL website and look under the CT2 model and you will see the carb parts list there.

'O' ring part number is 214-14147-00 and is still available from Yamaha.