Topic: The carbs on my 78F

[tofan]

I recently picked up a 1978 CB750F and in process of going through the carbs. This is my first time working on PD carbs.

Engine serial # CB750E-3152880
Frame #CB750F-2252813

The attached image from CMSL says that it should have PD41B (B) carbs, but I found out that I have the PD42B (A) carbs. Does it matter? I'm not sure what the difference is.
Edit: http://www.hondachopper.com/garage/carb_specs/carb_specs.html has it listed as PD42B so maybe it's ok?

Also, this little plastic spacer (attached) that's part of the link arm set is broken and the others are not there so I'm looking for replacement. Just 1. Anyone have any?

[HondaMan]

The PD42b carbs are the lower-emission carbs of the 2 types. They have a different float height (for a slightly lower filled bowl level) and leaner pilot jets, but otherwise are the same. The linkage has some minor variations, there are 3 slightly different versions (differing felt seals, number of spacer washers, that sort of thing). If you keep all the parts during your teardown they will work fine, though.

I usually photograph each step during teardown so I get all the right parts in the right places on reassembly.

[tofan]

Thank you. These carbs have a lot more moving parts than what I'm used to.

The PD42b carbs are the lower-emission carbs of the 2 types. They have a different float height (for a slightly lower filled bowl level) and leaner pilot jets, but otherwise are the same. The linkage has some minor variations, there are 3 slightly different versions (differing felt seals, number of spacer washers, that sort of thing). If you keep all the parts during your teardown they will work fine, though.

I usually photograph each step during teardown so I get all the right parts in the right places on reassembly.

[HondaMan]

For that flat nylon washers: if I don't have a part on an old set of carbs (they are getting pretty skinny now) I use (in order):
Ace hardware
PartsNmore (once in a while they have them)
eBay (except for scalpers...)
CMSNL - last resort, but often can get them when no one else can.