By replacing the butterfly carb on a 84 shovel with a CV carb will it help reduce vibration at all .

Ah, must be a trick question. 

yes of course it will.

The original butterfly carb performs very well apart from annoying vibration over 85 ks , I have been given a good Keihin CV carb but would not waste my time fitting it if did not reduce vibration at all. The bike is a 84 FLHX so I wish to keep it visibly original as possible and to fit the CV I wont be able to retain the ham can air cleaner so I wish to be sure of eliminating some vibes for that sacrifice and I know I wont be able to get rid of all of them, Its a shovel so I have to suck up some vibration its the nature of the beast , Im just trying to tame it a little. I have installed a Dyna 2000 ignition but to no avail, Interesting though when I acquired the bike it was almost vibration free but the past owner had set the ignition advance timing well after TDC and I don't wish to put it back to that setting . Hope one of you guys out there can help 

The Shovel's are mounted rigid to the frame, & don't have counter-balancers like say late softail .

No, not at all.

On the carb though,

I liked the old butterfly Keihin on my '86 Softy. Easyriders magazine had an article in '84-'85 on tweaking the Keihin, dunno it you'd get the bits now, but it cost me $27.50 back then for the jets and the older style higher volume accelerator pump. You had to epoxy up the hole in the bowl filling the pump, and drill out the passage to the old one (still part of the later casting). Align the pump jet to hit both cylinders, and as I live in the North and have no need for a choke, I removed the choke plate and shaft and sealed the holes. Issues were that the accelerator pump fitted to the later Keihin butterfly carbs was too small and refilled too slowly.

Access to the idle adjustment screw was sealed from the factory too, but that was always sorted straight up by the dealer.

There was a little more on thinning the throttle plate, shaft and screws, but I didn't bother going that far.

Transformed the carb completely. Used to get a laugh walking into Rollies in Brissie and seeing a basket full of used ones for $5 each. 

Thanks krash and smokey , that's what I wanted to hear, the CV wont reduce vibes.  My butterfly is in very good condition at a genuine 20,000 mile and I get on well with it but Im sure the CV is a better carb and when I can do something about keeping the horrible ham can air cleaner I may install it at some stage , the backing plate collides with the vacuum chamber and a spacer will push the air cleaner out too far.  The last guys fix by retarding the ignition helped keep vibe down to a reasonable level but im sure that old shovel didn't agree.

I bought new shovels back in the day, I still have a couple of 4 speed shovels, they cruise nicely at 90kph, I also have a couple of 5 speed shovels and they will cruise comfortably at 110kph, it's the nature of the beast,

Just check once in while everything tight, & they are not too bad.

Even my Evo vibrates things loose, you get to know what to check after owning one for a few years. I carry a small bottle of medium-strength Loctite in my toolroll!

your right far canal ill just have to suck them up, have used the bike for a while and it had very minimal vibes but I decided to put a Dyna2000 on because I felt the old ignition may become unreliable because of age and that's when I found that the ignition timing was set very retarded so I corrected it and presto I had vibrations , have moved the timing back and forth within spec but still vibes and Im not going to retard it to the stage it was originally set at  just to delete vibes. not nice for a good motor . I just wondered if a CV carb would help as I have one  but apparently not so will leave the butterfly on for now  as it works very well

Shovels look funny with cv,s on ,