1978 CB550 F2 Carbs

[heliwilly]

I am about to get the carbs sorted out on my project CB550 F2. They are keihin carbs. What model of carb was fitted to the cb550 and are the

carbs marked in any way that will tell me what model they are?

Thanks Bill W.

[deltarider]

Yes, for the CB550F models they are supposed to be 069A. See pic where that number is stamped in.

[heliwilly]

Thanks.

Bill W

[peterengland]

I have PD46A carbs on mine, once clean they are fine despite other 'views' on them, also have fast idle screw which they should all have, but don't.

[heliwilly]

Hi,

When I got the bike, the carbs were fitted with bellmouths like the old Monobloc carbs.

Would keeping these be OK or would a change back to the original airbox and filter be a better option?

Cheers  Bill W

[Bryanj]

Bill, if the person that fitted the bellmouths sorted it out propely then run with then but you will get more bore wear due to dirt ingestion. If you read a lot on the US site you will find getting Hondas to run properly on anything other than standard  settings is a nightmare. As a multi million pound company Hondas R&D spent a lot of time and money getting their bikes to run properly using inleaded 2 star all over the world and pass emission regs

[heliwilly]

Brianj,

Thanks for the reply. As you say I think it makes sense to go back to the original airbox.

On that note, does anyone have one lying around they would be willing to part with?

If so how much do you want for it?

Thanks  Bill W.

[Bryanj]

I havent got my parts books here on holiday but i think the F2 was the same as the 500. You need to research on cmsnl and check. If it is try ebay.com as everything from 71 to 76 will fit.
There are 2 parts to the airbox and 2 brackets(that are not easy to get now). Rubbers from box to carbs can be bought pattern.

[Nurse Julie]

I may have one Bill. I'm out this evening but will PM you tomorrow.

[heliwilly]

Thanks Julie.

Bill W.

[Nurse Julie]

Just sent you another PM Bill.