Topic: Needle differences between 064A and PD41B

[AbbyRider]

I've posed this question to our resident carb expert as well, but in meantime, I'm wondering if anyone knows if there's a difference between the actual needles for PD41B carbs versus the 064A.

Reason I ask is this: I've got '77 CB750F with the PD41B's. Thought I had adjustable '77 needles in it, but going through the file of receipts etc from PO and I see one for NOS needles for '75-'76 CB750F. Looking at the master carb listing here on the site, looks like those needles belong to the 064A carbs.

Since I've been having continual struggles with an extremely lean condition while riding (not while idling) and have raised the needles as far as they go and keep putting larger main jets in, I'm thinking that perhaps the 064A needles are a bit fatter or something? I can see this being the cause of my lean condition if that were the case.

I don't have any needles to compare to, and I can't find any literature giving those kind of specifics for the needles.

Obviously I'll go through the process of finding proper needles, but while I wait for that to happen, it would be good to have some kind of confirmation that this could be the cause.

Thanks.

[lucky]

The 1976 needles are the same as 1978 needles.
I measured them to death. They work.

The 1977 needles have 5 grooves unlike the 1978(non adjustable) which only has one groove.

The Honda part no. stamped on the needle only means what model it was on.
Many Honda parts are interchangeable even if the number is not the same.
I asked American Honda about this.

For instance float needles can fit hundreds of brands, and models.

The 064 model carbs from the CB750F had adjustable needles and the stock needle clip position was the middle groove or 3rd groove down.
I do not know if that needle had the same measurements as far as taper as the CB750K.
I would bet that it was the same, but you will have to use your calipers and compare.

[754]

If it's a single taper, you. Can overlap them taper against taper..with round ends facing out. ( that is if you have both needles)
 If the tapers are identical, shaft will be parallel..
 That may help in your comparison.

[AbbyRider]

Thanks. I didn't have any of the original needles to compare. But have some coming, thanks to Merritt MC Salvage. Frank - you ever used them? They've got a whack of stuff. Too bad they won't let you just drop in though.

[MiGhost]

I've gotten some things from Merrit. It has always be good quality, well cleaned pieces. I am sure that you will have no problems with what you are getting from them.