OS Carbs - 21J Ver 1,2,3
 

Hoping someone might have some insight into the differences between the 21J carb versus the 21(J).

The 21J was standard on the Spec II engine while the 21J(B) carb was standard on the B2101.

I'm considering placing the 21J carb onto a B2102 as I have heard the tuning performance is much better. than the stock 22C carb.

I have noticed there are more recent versions of the 21J carb as well (i.e 21J2 and 21J3, included on the new Drake Motor). Not sure if these would be better alternatives?

Any insight would be appreciated! Thx!

Put the 21J off a Tessman on my 2102 and it works awesome

Hello skrichter,

The O.S Carburetor in each engine model are as follow,

21XZ-B Spec I - Type 21J2(B) - 2010
19XZ-B - Type21J2(B) AR6.0 - 2011
21XZ-B Spec II - Type 21J(B) - 2013
B2101 - Type 21J(B) R6.0 - 2014
21XZ-B Spec III - Type 21J3(B) R6.5 - 2016
B2102 - Type 22C(B) R6.0 - 2016
B21AD - Type 21J3(B) - 2017

21XZ-B Spec I and 19XZ-B has Short Metering Needle (Low Mixture Needle)

The above Carburetor are the only two that has Short Metering Needle (Both with same Needle Part Number). 21XZ-B Spec I comes with 6.5mm Venturi while 19XZ-B comes with 6mm Venturi.

XZ-B Spec II and B2101 have the same Carbutetor, the only difference is the Venturi type. The B2101 has the newer type Venturi.

XZ-B Spec III and Adam Drake have the same Carburetor, the only difference is also the Venturi.

The above four Carburetors are actually the same, the only difference is the Thermal insulator design. The 21J3 Body has the newer Black Insulator without the additional lower thin ring.

B2102 Carburetor is the different between the rest.

Hope this is clear enough.. ;)

Cheers.. :)

Perfect!!!! I can't thank you enough for taking the time! Much appreciated! :tire:

I'll take the carb out of my Spec II and place it in my B2102 and see how that turns out.

You can look right in the top of the slide and see a big difference.

The 22c has a built in 6.5mm (or so) restrictor. In case you mix them up..

The 21j carb is more user friendly.

Hello jersey,

Please see my updated post above..

Cheers.. :)

Stanley,
I have both V1 and V2 Protek Samurai's, which the only difference is the carb. V2 comes with the 22c carb. I have a mixture of carbs with black insulator and old style.
So do I only need to use the thin black ring with carbs that have the old insulator??

Hello kek,

Yup.. With the older style Carb that comes with translucent insulator, You will need to place the Black thin Ring at the bottom of the Carb inlet opening. If You are using the newer Carb with Black Insulator then You don't need the Black Ring.

Cheers.. :)

Thanks for this perfect list. Could you also tells us where the 22D and 22E fit in from the 2019 OS 2103 engines?

and whats the best one :lol:

Just wanted to bump this thread.

A question above asked about the 21j (v1-2-3) carb bodies being all the same... do all the carburators that have a j on them only say 21j!? Or do the 21j2 j3 say 21j2 21j3 on the body? Because I have a lot of os carbs and even some from newer engines that should have the j2 or j3 set up, but the body on say 21j. How are we to know if it's the v1-2-or 3 if All the carbs only have the 21j only. I surely have a couple 21j version carbs of each j1-2-3 but I can't tell a difference between them when they all say 21j and that's it. Also I do have a few 22 carbs, can these internals be changed out with the better needles from the more consistent needle set ups from my other 21j carbs?

I hate long needles although os is better then most, I was doing some camparisons in the ​​​​​speed line and it should apply to other similar carbs. From the parts list all you need to change to go from from a long needle to a short needle is 22082340 short needle instead of the 23818340 long needle. The spray bars/mid have the same part number. So you shouldn't have an issue with it seating and can tune old school style as long as the high speed had enough range.

@ rockinthecashba Why is a short needle carb easier to tune?