Topic: Honda CB750 Carburetor Advice

[kyle750]

I have not spent any time with my CB750 K1 carburetor. Very dirty on the outside and looks like it has never been removed or cleaned.    1 carb leaked during startup but the leak quickly stopped. I was not planning on removing the carb rack anytime soon as the bike runs - if it ain't broke don't fix it.   Carburetors intimidate me and I was saving the disassembly, cleaning, and synchronizing until my skills set improves.

This carburetor came up for sale locally.  According to the seller it is from a 1971 CB750 and looks like it has been cleaned.  Price is very reasonable with no shipping or import taxes to pay.

Should I wait to do a proper inspection and evaluation of my carb or buy this one??

[BenelliSEI]

Those carbs do look nice and clean. If you want the four rubber boots installed that are missing on the tops, you will have to split the rack. While it’s apart, I always replace the “0” rings that slip on to the fuel tubes that connect the carbs.

However, if your carbs work well, just give them a good wash and go with what you have (and know works). Leave them right where they are, soak them in a good degreaser and power wash. You won’t hurt them. Pop the float bowls off (only held on with clips) and get your fantastic helpers to give them a polish (inside and out). They will look great and you know they work.

[kyle750]

For comparison here is a quick photo of my carb

[pickleknuckles]

Imo, if it ain't broke and the bike runs well, don't open a can of worms.
As far as the other carbs, I'm a fan of having spare parts on hand just in case.

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[BenelliSEI]

Yours look fine. Soften the corrosion up with a soaking in WD40, hot water and detergent wash and rinse. Polish the bowls and they will be fine!

Better the “devil you know” than a new “can of worms”.

[kyle750]

Checking the seller of the CB750 carb and it looks like he specializes in restoring Japan carbs - Keihin and Mizuni.  Here are some photos of his other carbs for sale.

[MauiK3]

Hondaman's book for 750's is a great resource, if you don't have it, get it, it helps.
Extra carbs are a great thing to have. Keep yours running and put the extras on a shelf for the day you need them.

[kyle750]

Many thanks for the excellent advice. A Thai friend has been in contact with the seller of the K1 carburetor - seller has been very helpful and quick to respond.  Communication is often challenging but here is what I understand:

No crack. If any parts are damaged, there are spare parts.  If the carburetor  is damaged and cannot be used he will refund the payment. Seller also said I can send my carburetor to him for disassembly and cleaning  once it is removed from the bike. Any parts needed for the rebuild will need to be sourced and cost extra.

When finished look like new

It is my understanding that it is best to keep all the original keihin parts that are original to the carb and not replace.  Just a reminder that removing the old carb is not an undertaking that I am planning on anytime soon.  I try my best to only start a project when I have everything needed to complete the task (new carb boots, clamps, dust caps will be needed) 

[kyle750]

Nice Work

https://youtu.be/PTfsY1Wp0-c

[kyle750]

I decided Not To Buy the K1 carburetor.  Until I can properly evaluate my carb buying a replacement (when it might not be needed) would be "jumping the gun"

"I'll cross that bridge when I get there"     Thank You Gentlemen!