What size CV carb do I need?

I'm in the process of changing my stock Keihin butterfly carb with a CV carb. I assumed they were all 40mm carbs and almost bought a 38mm.
I'm putting this on my 1988 FLHTC, and now I'm not sure what size I need, 38mm or 40mm. Does anyone know what size I need? I was assuming it needs a 40mm but now I'm not sure.
Does anyone know if there's a chart somewhere with the different model numbers of the CV carbs and what sizes they are, something I can use to determine what model # will work for this bike
Thanks again,
Snyde

All the CV's on Harley's are 40mm from 1990 -2004 or whenever they stopped putting carbs on them

40 will work very well on your bike

Hello again,
I thought the 40mm is what I need. My confusion came about when I was bidding on a Harley CV carb part # 27421-99C. It's from a 2002 Dyna Wide Glide. I figured that carb would work ok on my FLHTC, but when I did a Google search for 27421-99C I got a bunch of hits back referring to 38mm carbs. Here's one of the hits:
38mm Keihin CV Carburetor, Replaces 27421-99C, fits Big Twin*::*Keihin and Related*::*Motorcycle Carburetors*::*For Harleys*::*Engine*::*K and G Cycles...kinduvabigdeal!!!
Here's another one that says it's a 38mm:
38mm Keihin CV Carburetor OEM 27421-99C SKU 35-9283
Is there a list of these CV carb's part numbers so I know what's what, or is there some way by looking at the part # if it's 38 or 40?
Thanks,
Snyde

Those are way over priced, if I'd know you wanted to pay that much I'd never have sold the ones I've sold for under $100.00.
I don't know about 38 or 40mm I thought the stock ones were 40mm. Anyway here is the one you need.
Many don't come with a choke cable. The one listed above is a good buy ask anyone on here. It won't last long.
This site changed the web address for the carb I was trying to show you, I am sending you a regular email with the site.

Here's the confusion:
You told me above that I need a 40mm carb, when I looked at this carb on eBay it lists it as a 38mm.
The manifold I'm attaching the carb to is P/N 27019-89
Whatever carb I get has to work with this.
I agree about the high price of the carbs on that site. I'm not going to buy there, I was just showing how those links showed them as 38mm.
My plan is to buy SOMETHING from eBay, for lack of a better deal.
I also wish you hadn't sold those carbs, I would have bought one.
Thanks for the help,
Snyde

I bought my CV carb from kenfuzed,he put all the CVP goodies in it,you might send him a message to see if he has any.The carb I have works great....

Snyde,
check the ebay site in the second email I sent ya, there are some real good deals in there, like the add with 2 carbs. Any of the cv's will fit the slip in manifold. I believe they are all 40 mm. I have one CV that has been on a 1990, 1996, 1997 and is now on a 2002 fatboy. It has worked very well on each of them.

I've been cruising eBay for about a week now, I've got all the good CVs saved and am going to buy one of them. I was going to bid on the one that was a "brand new take off", the guy said it came off his 2002 Dyna Wide Glide . When I Googled the P/N and it came back as 38mm I "flinched". The guy selling the 2 carb auction lives about 30 mi. from me in Batavia, NY. If I'm lucky enough to win it I may just drive over and pick them up.
Thanks for your continued help!,
Snyde

the part numbers don't really mean much on a cv cause they are basically the same thing, at least all the ones I have bought are the same. Make sure you get a choke cable, those are harder to find. although I think CV Performance has them and a cool little bracket to mount the choke on the carb side of the tank. CVP Choke Bracket - Accessories by CV Performance

I see. Am I making too much out of this 38mm, 40mm thing? I just wanna make sure I don't buy something I can't use. As far as I can tell I've got all the parts I need, except for the carb. I've got your air cleaner, a manifold, and if I can use the same throttle cables from the butterfly carb I think I'm set. I just don't want to start this project until I have all the CORRECT parts, I KNOW they're gonna work for me, and I can go seamlessly from the butterfly to the CV in an afternoon and be riding later that day. The butterfly carb on there now is running much better than it was since I rebuilt it a few weeks ago, except for the occasional "cough" through the carb. That was the whole idea behind this change to put something on there that isn't gonna "cough". Before I rebuilt it, it was coughing so much I had to run it with the choke on partially all the time. The rebuild fixed that, except for an occasional cough.
That choke bracket thing is pretty cool, I'll probably get one.
Thanks again,
Snyde

I would say 38mm is a misprint...if it has a HD part number it's gonna fit your bike and manifold,I don't remember or ever heard of HD dropping down to a 38mm CV but they do have a CV44...do you have the flanges and gaskets for the manifold??

I believe so, I've got the original butterfly carb's manifold flanges. I assumed that the CV manifold I have will fit in the same flanges. I've got new manifold gaskets too.
Thanks,
Snyde

In another thread he posted he has a CV manifold from a 1990 Evo,I'm not sure if the flanges from the butterfly carb's manifold are the same or not...
yep, he will need a CV backing plate to mount on the CV 'cause the holes from the butterfly carb won't line up with the CV carb

I've got a 1990 CV manifold and a early '90s Screaming Eagle air cleaner kit with backing plate. The only thing I DON'T have, (if there is any difference), is the CV manifold "clamps" that slip on the manifold and bolt to the heads,(that's how it is on my butterfly carb anyway). I'm not sure if this is how a CV manifold is attached.
Do you guys know?
Thanks,
Snyde

Here's a pic of the flanges

Front
NOS PARTS - database:


Rear
NOS PARTS - database:

The manifolds are different...on your butterfly carb the manifold clamps to the compliance fitting which bolts to the head, the CV manifold eliminates the compliance fitting and uses the flanges and seals...the intake seal part number is26995-86B (2 of them)and flanges are27009-86A Rear and 27010-86A Front and a manifold seal to mount the carb to the manifold pt #27002-89 all still available at your local dealer

Thanks for the part numbers! I found some on the Net and ordered them earlier today. I live in a rural area quite far away from a HD dealer and it's easier, and cheaper now with gas prices what they are,:cussing: to order them off the Net.
Now, if I don't need different throttle cables, I'll have everything I need, thanks to ALL of you guys!!!!
Take care,
Snyde