Not quite sure where we are here. Is this the carb you HAVE, or the carb you WANT to install. That looks like the garden variety Keihin CV outfit to me. Part numbers they were sold under varied as varying emissions standards forced the MoCo to adjust jetting over the years.


I ask because there were "Screamin' Eagle" butterfly carbs (as was mentioned above). Harley also sold a "Screamin' Eagle" CV carb which was a larger version of the Keihin CV carb (44mm vs. 40mm stock).

 

Looks like this.

 

Hi all, I seem to be confusing everybody…..
So, pull up a chair and grab a cold beer while I review the situation…..

Currently on my 1995 Fatboy there is a Screamin Eagle Keihn butterfly carb that was fitted some years ago by a Harley dealer, before I owned the bike.
I have found it difficult to keep set up correctly and am currently only getting about 35 mpg (that’s UK gallons which are larger than US gallons). As the bike is standard apart from a mild cam upgrade, that’s not good.

Now I have offered a free standard 1995 Harley CV carb (photos in an earlier post) and have been considering fitting it as a replacement.

My questions are two-fold……..

First, should I fit the CV carb, or persevere with butterfly carb?

Second, the spare carb I have is part number 27088-95, and this was fitted as standard to a 1995 International FX…... but why is there a different part number for the carb fitted as standard to a 1995 Fatboy (27206-93A) ?
Surely the engines were the same?

Obviously this second question is just out of curiosity.

 

Texashillcountry / Outlaw.......

Below is what I have for quick reply on my computer screen....although I have found 'Additional Options' in the main 'Reply to Thread' allows me to attach a photo.

The quote option isn't working for me either tho'

 

From what I have read by people smarter than me (damn near anyone!!) is that the CV carb is a huge improvement over the butterfly carb.

Since you have the opportunity to get a free CV carb I say try that and see what you think.

That said I tossed my CV carb (that I couldn't get to run right) in favor of an S&S Super E and have been happy ever since.

 

Send a message to terry or one of the other moderators and see why you don't have the symbols.

It could be a setting in your User CP.

You have damn sure been here long enough to have the privileges!!!!

 

Entertain this theory, Maybe your having a tough time of it with getting the Keihn carb to run to what you think it should be because Maybe the motor it's built more than you think. Causing the poor fuel mileage. You really do need to figure out what cam is in There. "A mild cam could be anything" maybe you should do a compression test first and then take the cam out to see what you really do have. Then make a reasonable choice as to which Way to go with carburation. I currently believe you are throwing darts at balloons to "Maybe" win a prize.

One other thing do you know what gear ratio you are currently running and is your Speedo registering correctly?

 

Since you set a carb on the condition of the plugs why does any of that matter?

 

I have a 'sales list' of what the Harley dealer had done.
It was mainly cosmetic apart from uprated brakes, 'Screamin Eagle performance butterfly carb' and 'Screamin Eagle performance cams'.
No other work was done to the engine. So it would have standard compression.

It now has a Supertrapp Fatshots exhaust system.

If I rebuild and fit the CV carb, any suggestions as a starting point for main and slow jet sizes?

 

Use the CV, it is a very good carby and once set up you never need to touch it again. On UK gas I would set it up like this:


48 idle jet, N65C needle OR stock needle with a 2mm shim under it and a 195 main jet.


That will be a good starting point and then just do a few plug chop runs (cruise at various throttle openings, hit the kill switch and look at the plug colour...grey is good, black is OTT and white is danger).


Should run well with no flat spots or stumbling.