Author Topic: Pb style carbs?  (Read 497 times)

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Offline mr.brandon

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Pb style carbs?
« on: February 11, 2023, 07:56:34 AM »
Hey all, I am currently trying to solve a little bit of a mystery and find out whether or not my carbs need an o-ring and washer in a certain place and first need to find out whether or not my carbs are a "pb style". I have a mixed rack but on said rack, 3 of them are stamped (657b) and the other, (657a). Anyone know if 1 or both stamps would designate them "pb style" carbs. Thank you

Offline bryanj

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Re: Pb style carbs?
« Reply #1 on: February 11, 2023, 09:37:34 AM »
Thats PD not pb and easiest way to tell, apart from numbers, is the shape of the top.
If the top lid is a P shape with a screw at top and bottom
If the top lid is coffin shaped with a screw each side its a 500/550
If its screw on its 750
Semi Geriatric ex-Honda mechanic and MOT tester (UK version of annual inspection). Garage full of "projects" mostly 500/4 from pre 73 (no road tax in UK).

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Online newday777

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Re: Pb style carbs?
« Reply #2 on: February 11, 2023, 10:31:02 AM »
657 carbs are not PD carbs.
If you had posted a picture in the last thread you would have gotten better information.
Only PD carbs have that washer and oring like was told you by others in that other thread you have running....
BTW keep it all in one thread rather than starting another on the same subject so all the information is in one spot and you get the correct answers.
Stu
Honda Parts manager in the mid 1970s Nashua Honda
My current rides
1975 K5 Planet Blue my summer ride, it was a friend's bike I worked with at the Honda shop in 76, lots of fun to be on it again
1976 K6 Anteres Red rebuilding project, was originally my brother's that I set up from the crate, it'll breath again soon!
Project 750s, 2 K4, 2 K6, 1 K8
2008 GL1800 my daily ride and cross country runner

Prior bikes....
1972 Suzuki GT380 I had charge of it for a year in 1973 while my friend was deployed and learned to love street riding....
New CB450 K7 after my friend returned...
New CB750 K5 Planet Blue, demise by ex cousin in law at 9,000 miles...
New CB750 K6 Anteres Red, to replace the totaled K5, I sold this K6 at 45k in 1983, I had heavily modified it, many great memories on it and have missed it greatly.....
1983 GL1100A, 1999 GL1500 SE, 1999 GL1500A

Online newday777

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Re: Pb style carbs?
« Reply #3 on: February 11, 2023, 10:38:01 AM »
657A and B are both roundtop carbs from 1972-1976.
A and B just refer to the years they were used on and jetting that came in them from the (but jetting could have been changed over the years)
Stu
Honda Parts manager in the mid 1970s Nashua Honda
My current rides
1975 K5 Planet Blue my summer ride, it was a friend's bike I worked with at the Honda shop in 76, lots of fun to be on it again
1976 K6 Anteres Red rebuilding project, was originally my brother's that I set up from the crate, it'll breath again soon!
Project 750s, 2 K4, 2 K6, 1 K8
2008 GL1800 my daily ride and cross country runner

Prior bikes....
1972 Suzuki GT380 I had charge of it for a year in 1973 while my friend was deployed and learned to love street riding....
New CB450 K7 after my friend returned...
New CB750 K5 Planet Blue, demise by ex cousin in law at 9,000 miles...
New CB750 K6 Anteres Red, to replace the totaled K5, I sold this K6 at 45k in 1983, I had heavily modified it, many great memories on it and have missed it greatly.....
1983 GL1100A, 1999 GL1500 SE, 1999 GL1500A

Offline ekpent

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Re: Pb style carbs?
« Reply #4 on: February 11, 2023, 03:32:35 PM »
657 carbs are not PD carbs.
If you had posted a picture in the last thread you would have gotten better information.
Only PD carbs have that washer and oring like was told you by others in that other thread you have running....
BTW keep it all in one thread rather than starting another on the same subject so all the information is in one spot and you get the correct answers.
Think were up to 3 threads on this same thing.

Online Deltarider

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Re: Pb style carbs?
« Reply #5 on: February 11, 2023, 11:16:05 PM »
657 carbs are not PD carbs.
If you had posted a picture in the last thread you would have gotten better information.
Only PD carbs have that washer and oring like was told you by others in that other thread you have running....
BTW keep it all in one thread rather than starting another on the same subject so all the information is in one spot and you get the correct answers.
Think were up to 3 threads on this same thing.
Brandon, did you receive my PM?
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