AT2 carb # 316E1 = M.J./230 ... N.J./0-6 ... J.N./4F10-3rd ... Slide/1.0 ... P.J./40 ... Air Screw 1&1/4 ... Float 15.1mm

AT2/3 carb #316E2 = M.J./200 ... N.J./0-6 ... J.N./4L6-2nd ... Slide/2.5 ... P.J./35 ... Air Screw 2 turns ... Float 21mm

AT3 carb # 316E3 = M.J./230 ... N.J./0-6 ... J.N./5J3-3rd ... Slide/2.5 ... P.J./35 ... Air Screw 2 turns ... Float 21mm


CT2/3 carb #314E1 = M.J./200 ... N.J./0-6 ... J.N./4L6-3rd ... Slide/2.0 ... P.J./25 ... Air Screw 2 turns ... Float 21mm

CT3 carb # 314E2 = M.J./230 ... N.J./0-6 ... J.N./4J13-2nd ... Slide/2.0 ... P.J./25 ... Air Screw 2&1/4 ... Float 21mm

So, i guess there's not much difference between the CT2 carb and CT3 carb? I looked at the CT@ and it has the 200 jet and the CT3 is running the 230. How will that effect performance if I use the 200 or the 230? Pilots are both 25.

This should help some who want to visualize.

I guess what I am wondering is should I stick with the 200 or go on to the 230?

Which needle are you going to use?

Forget I asked that... here's what I would do... use ALL the jets and metering needles from one or the other. Don't mix and match and you'll be fine.

Holey Moley, even though I did not get a topend with the slide and needle on the boneyard carb, I see the metering needles are different between the CT2 and the CT3...hey, thanks for pointing that out!!! Saved me a mess....!!

For reference, I have a CT3. I am running a 220 main because the 200 was a little lean. Jet it till iI blubbers a little on the top end and go down a size. You can adjust with the mixture screw.

Since the E2 carb did not have a needle I assume I cannot even use the carb body without the proper needle. The E1 carb that came on my bike has matching parts so I am stuck with the carb body that is a bit questionable (float bowl shattered in pieces) I was gonna mix and match parts by putting the E1 parts into the E2 body. Now I realize that the Metering needles are different. I suppose if I had the proper metering needle I could work out the jetting. I assume the E1 needle is a different shape or thickness than the E2 needle which I don't have. Just by looking at the numbers I provided here that is most likely the case. I don't know how Mikuni sizes the needles or if I can get what I need. I guess if I want to use either carb I could post for parts on either carb and see if someone has the proper needle. The E2 is missing a idle screw and the air screw had to be taken out because whoever owned the carb had ruined the air turnout screw. To get it out I had to drill and back it out with a screw extractor a pic i posted in another thread. Luckily the E2 bowl and floats will work in the E1 with no problem. I can even use the pilot or the float needle and float valve from the E2 in the E1. I will have a functioning and complete carb with better float and newer float bowl. I came out ahead but the guy at the boneyard charged more than the E2 carb was worth. I realize that now, but lesson learned.

You can use the other body if it is the same! (And it should be identical except for the tuning parts.)

All the "tuning" parts (jets, needles, etc) can be swapped over.

All I was saying is don't use the main jet from one with the needle/needle jet from the other.

Got that Bro, I gotta say, I just swapped E1 parts into the E2 body which I cleaned, Kept the E2 float and needle valve which was better and put all the E1 Jets in and transferred the Idle screw and air screw and choke and used my E1 metering needle and cap.... Bike now starts and idles better than before. Waiting on new petcock which should help things greatly. Your advice was spot on....Thanks so much. I will also seek to get the parts to rebuild the E1 carb the way it should be.

Digging this old topic up. Has anyone found a 5J3 needle? seem to be non-existent to me.

UPDATE: found some on EBay once I found the Yamaha p/n to Mikuni P/N cross reference,