Any OEM carb choices for the FJ ?

[T Legg]

Mikuni sells them set up for different spacing. The FJ spacing is 77-85-77. The carb spacing is adjustable but you want to buy them already set up for an FJ. The models that fit the FJ are RS36-D8-K and the RS38-D35-K . They use the stock intake manifolds but you will need individual pod air filters. RPM's great dual pod filters unfortunately won't fit. You will also need a motion pro throttle tube assembly and push pull cables. One plus is that replacing a set of cables is much cheaper than replacing a set of oem FJ cables.
 They come with a manual pull choke. My first set of carbs have a bracket that allows the use of the stock FJ choke set up but I don't know if those are still available. I don't use the choke anyway. With the accelerator pumps I just twist the throttle twice to pump in a little gas and the bike fires every time even at below  freezing temperatures.

[Warp84]

Mikuni sells them set up for different spacing. The FJ spacing is 77-85-77. The carb spacing is adjustable but you want to buy them already set up for an FJ. The models that fit the FJ are RS36-D8-K and the RS38-D35-K . They use the stock intake manifolds but you will need individual pod air filters. RPM's great dual pod filters unfortunately won't fit. You will also need a motion pro throttle tube assembly and push pull cables. One plus is that replacing a set of cables is much cheaper than replacing a set of oem FJ cables.
 They come with a manual pull choke. My first set of carbs have a bracket that allows the use of the stock FJ choke set up but I don't know if those are still available. I don't use the choke anyway. With the accelerator pumps I just twist the throttle twice to pump in a little gas and the bike fires every time even at below  freezing temperatures.

Thank you for the information. You've given me a lot to think about. But I do have another question. Is the requirement for the airpod filters a matter of space the new Carbs take? Or simple a matter of the boots between the airbox and the carb not being remotely compatible? Or Thirdly, a matter of needing a direct airflow path regardless.

If the issue is merely the connection between the airbox and the RS36/38's being the problem, I can actually make custom ones since it's on the cold side and won't destroy injection molded TPU.