Topic: What do I have in my 087A carbs?

[denward17]

'76 550K

Plan to take apart all carbs and replace all o-rings, gaskets and such.  Bought the kits from SouthSound Honda.  Plan is to re-use the existing brass (I hope).

Took one carb apart and see #100 main, #38 pilot, with no other markings.  How do I know if these are aftermarket?

The needle is D26, with clip in the 4th position from top, that's all I know right now.  From other threads I have searched, this appears to be "OEM" configuration.

Could these be original?

Thanks for any insight.

[BenelliSEI]

They sure look to be original. What did the inside of the bowls look like?

[denward17]

Just took one off, but it looked pretty good.

[CycleRanger]

https://www.jetsrus.com/FAQs/FAQ_fake_genuine_jets.html

Like it says here, most but not all Keihin jets/needles will have a stylized "K" stamped on them.
If there is no "K" there are other methods to determine authenticity by comparing them to known genuine Keihin jets, but the differences are subtle.
The needles are generally the most important bit that needs to be genuine, imho.

Generally there are signs that a set of carbs has been worked on before, buggered screws or jets and such.
Regardless if the brass in the carbs is in good condition and all the same I would reuse it even if you can't determine if it's original as it's good place to start.
The bike may run fine with the existing jets. If not you can always seek out alternatives later.

[BenelliSEI]

+1 to above. Reuse all the brass, replace all the rubber. Bench sync and go from there.

[Deltarider]

D26 indicates it is a Keyster part. Consult the overview below that also covers your model. In my CB500 and for over 140.000 km all original genuine brassware is still present and there's no indication of wear.
I have renewed a few O-rings, around the main jets and drain screws. That's all I ever had to do. All the other rubbers are still the ones bike got at the assembly line in 1976...

[TwoTired]

If the needles are stamped with D26 instead of the Keihin 5 digit number, I would expect all the brass is now aftermarket.

If the bike has been running rich, now you know why.

[denward17]

Thanks Guys, I never heard the bike run so starting from scratch.