Mikuni 33 flatslide carbs

[Karl321]

I'm looking at a 92 FJ1200 that has Mikuni 33 flatslide carbs.  The seller says that the bike isn't running right, and believes the carbs are the problem.  My intention would be to buy the bike and do a carb rebuild.  Or possibly go back to stock carbs and sell the 33's.  I did a search here for any info on these carbs, but didn't find anything.

My research elsewhere tells me that this is a popular performance upgrade.  Any opinions or info that anyone can share about this upgrade?

Thanks,  Karl

Current bikes:
1986 FJ1200
1991 FJ1200
1979 XS1100 Standard
1979 XS1100 Special
1981 XS400 Special
1994 Yamaha Venture Royale 1300
1999 Honda Valkyrie 1500

[Pat Conlon]

Mikuni uses letters and numbers to describe their carb models.

The letters indicate what type of carb and numbers indicate the diameter of the throat in millimeters.
For example, for oem we have BS36 CV carbs on our FJ's the 36 is for 36mm throat size.

Mikuni also makes an RS36, RS38, and RS40 flat slides for our engines, along with TMR 36, 38 and 40 roller flat slide carbs.

My point....I seriously doubt you have 33mm diameter carbs on your FJ....if you do, then they are woefully undersized for our big engines.

If you have the Mikuni RS36 flat slides, you want to speak to T Legg (Travis)
https://fjowners.com/index.php?topic=19684.0