Topic: 1970 CB750 carb questions

[DaveInTexas]

A)  In my CB750 Shop Manual, there are notes on how the needle height can be adjusted - but I do not see anything on the technique to decide when or how much it needs adjusting.
Is this mainly a low speed f/a adjustment?

B) Is it correct that the only high speed f/a mixture adjustment is the jet size?

[Davez134]

The first 2 posts in this link should answer both questions in depth for ya. It's from carb FAQ section. I have referred to this many times...

http://forums.sohc4.net/index.php/topic,5410.0.html

[DaveInTexas]

Thank you for pointing this out, I will review and return if I have unanswered Q's.

[DaveInTexas]

OMG isn't that the motherlode of all things carburetor.

[Davez134]

OMG isn't that the motherlode of all things carburetor.

I know right! Figured it would be easier to send ya there than try to explain throttle positions. Don't know what I would have done without that info!

[DaveInTexas]

Ok I ploughed through all that plus my manual plus Clymers and have decided that (post corrections, please) :

A)  In my CB750 Shop Manual, there are notes on how the needle height can be adjusted - but I do not see anything on the technique to decide when or how much it needs adjusting.
Is this mainly a low speed f/a adjustment?

It looks like it is adjusted if the mixture at 1/2 to 3/4 throttle position is too lean or rich only.

B) Is it correct that the only high speed f/a mixture adjustment is the jet size?

This is correct as far as I could find in my readings; anyone?