Topic: CB750 carb IDs and differences - 086A, 657A and 657B & 7A

[mycb750k6]

Is there any way to know what the physical difference is in the 7A, 086A, 657A and 657B carbs besides the jets and clip positions they were distributed with or the year of the bike? Is there really any other difference? Could I mix and match assuming the same needles, jets and other removable parts?

[CycleRanger]

I have sets of all three and other than some very minor external differences they are as far as I can tell identical.
My K5 right now has 3 657B and one 657A bodies and it runs fine. Of course the jets and clips are the same for all four.
Here's a couple of shots of an A and B.  Note the slight external differences.

[mycb750k6]

ok thx. that's good enough for me.

[mycb750k6]

How about the 7a? Looks like I have a spare rack with two 086a's and two 7a's. The 7a carb bodies also look the same. Any reason they can't be used together assuming all jets are the same.

[bollingball]

I have sets of all three and other than some very minor external differences they are as far as I can tell identical.
My K5 right now has 3 657B and one 657A bodies and it runs fine. Of course the jets and clips are the same for all four.
Here's a couple of shots of an A and B.  Note the slight external differences.

Would be nice if they were all facing the same

[CycleRanger]

How about the 7a? Looks like I have a spare rack with two 086a's and two 7a's. The 7a carb bodies also look the same. Any reason they can't be used together assuming all jets are the same.

I am no expert, but I believe all the bodies are the same.

Would be nice if they were all facing the same

Huh?

[RobC]

I was looking on Ebay at carbs and there was one with 657A stamp for sale, but there was no inlet flange to mount the air cleaner tube.  It was cast with a smooth rounded opening, nothing to clamp to.  Seller thought it was for 750K.  Anyone heard of a special racing carb or something designed for no air cleaner?