I won't complain about CVs, but I like and run reguler Kehins with good luck. The problems come with bad gas in the CVs and reguler Kehins that plug the low speed jets. Not a big deal but still a pain in the ass. That maybe the only reason to run a S&S, those sewer pipe size jets.

 

Do not rely on a rubber flange with a clamp to support the carb.
You can get a press (glue) fit 2 bolt aluminum flange to put on the carb so it will bolt to your existing manifold.
The carb will still need to be supported at the filter flange.

Jets are easy to clean, get an allen screw set for the bowl screws at ace hardware.
And a long idle mix screw is handy.

Yes watch out for used carbs with broken plastic bits, missing cable mount, bad fuel inlet fitting, bad slide diaphragm, cut springs, over drilled slide, 883 needle, etc.

 

My absolute favorite carb for all of my old Harley’s, pans, shovels, and ironheads, is the old 38 mm Round slide Mikuni VM—9. Although rubber mounted, it is easy to fabricate a support bracket from the float bowl to the case. Also, Branch made a great air filter backing plate which makes for an extremely solid mounting arrangement . They can be found used .

 

I run a 90s factory CV carb on my big flatty. They are excellent and can be found cheap. Look for one that has had the plastic inlet elbow already replaced. CV performance has a nice extended pilot jet screw and idle screw to make adjustments on the fly easy.

I recommend a yost powertube kit. Stay away from the dynojet kits. Very easy to tune. I live at over 5,000 feet in Montana and have ridden it sea level in Florida. I think I had to do a 1/4 turn on the pilot jet just to smooth it out a little at idle. Its been a great performing carb so far. I also had to run an inline fuel filter as it would stutter sometimes from crap in the gas clogging things up. The petcock screen wasnt sufficient....haven't had a problem since.

As far as mileage goes...I'm guessing mid low 30mpg. I run my bike on the rich side though. Running out of fuel twice on a ride to sturgis a few years ago really helped me to figure out gas mileage...ha!
I was told once that putting this carb on my bike was like putting a mustache on the mona lisa. Guess I like my women hairy. It works great and cost 1/5 of an m51 or m74B.

 

What he said

 

Matt, with the Deco top on it, only a determined nitpicker would carp about your anachronistic carburetor.

Not that the woods aren't full of nitpickers.

 

I just swapped a junk bendix for a Chinese CV on my beater Shovel. I run a 90s HD CV on my Pan. I use the press on adapter for the intake but TIG them to the carb body being careful of heat so i can run standard carb supports etc and not have a worry. Also lil trick run a KLR650 choke cable eliminator. Puts the enrichner plunger straight out the side directly on the carb. Honestly $50 for a Brand new CV is a decent deal and the Shovel runs great with it. CVs are probably the easiest starting, cruising carb for an old bike in my opinion. But be prepared for everyone and their brother to tell you, you need a Super Alphabet carb or an SU. Go for it!

 

I'm gonna try one of those cable eliminators. I always hated that knob being mounted to the top cover. Thanks for the tip!

 

Thanks for the comments.

Back to the original question, are the cheap aftermarket CV carbs as good as the factory HD OEM ones?

We seem to have one positive vote for the aftermarket unit being usable, if not necessarily as good as the OEM carb..

Id prefer a factory one, Im just leery of buying one online without being able to see it in person.

 

I have no problem with the re-pop carbs, many are made on the same tools as oem.....
They are so cheap the risk is low. I have used many.

 

Thanks for the voice of experience.

Part of the potential risk in my case could be getting stuck out in the middle of literally nowhere Utah, Arizona, Wyoming, or similar that could cost many hundreds of dollars in tow/pickup/recovery fees if it died. In the past I had a bad habit of going stupid places way back on dirt roads looking for good camp spots, hunting places or just generally exploring and goofing off, something Im planning on doing again. Theres also the state BDRs (Backroad Discovery Route) which are long dirt road sections I want to ride some of.

If youve ever seen the vids of Matts Off-road Recovery, thats sort of the general idea, though I dont expect to be on quite as crazy of roads as some of his recoveries. Anything on dirt roads makes towing or recovery more expensive and more difficult to find someone to do it.

WyBDR Wyoming BDR Solo On A 1290...

AzBDR AZBDR and beyond

Some sections may be out of the league of a shovel, most are within the abilities of the bike and not much different than the Forest Service dirt roads i used to ride on my knuckle.

 

Don't make changes prior to a run.
Don't leave town on a bike that won't make it back.
ANYTHING can happen, but I have not been stranded for long at all, EVER.

 

Use the kehein CV not China shit. Also a jap carb hanging off the side of good US iron dont suit IMO

 

You realize Jap carbs been hanging off Harleys since the 70s right? Those Kayaba or Showa forks they've had since the 70s yup Japanese as well. Hell I bet most aftermarket carbs including S&S are made in Taiwan or China.

 

I know from the 70s harley used showa forks . Jap carb keinen . But an old flaty or knuck pan with a CV dont look right? S&S carbs have knock offs made in China. Any way stuff the knock off shit where it suits ya.

 

If in doubt (I would anyway) it's easy enough to inspect a generic CV via teardown prior to install. I find a burr now and then on the replacement mower carbs I buy but not often.

Unlike EFI carbs rarely fail in a manner that won't run (being too varnished from sitting to run is not a carb fault). I've never seen a properly assembled non-defective carb that failed to run due to any fault of the carb (MANY carbs, multiple bike makes over many years working a multibrand shop that had some horrors come in the door!). OTOH I've repaired plenty of EFI vehicles whose pumps wore out, stuck or ceased running including HDs (their pump is a basic auto industry standard design).

CV carbs are quite tolerant. It's pretty useless to run an SU with the dashpot removed but they do run (you get to raise and lower the slide manually). I've not tried that on a diaphragm CV because there was no reason to but if a diaphragm tears ti=you could do the old dirt bike fix for a busted cable and screw in the slide-lifting idle screw after starting and limp home at your choice of RPM. Diaphragm carbs abound on dual-purpose bikes like KLR 650s.

Of course round slide Mikunis work fine and Sudco have sold them since dinosaurs walked the earth. CV is mainly advantageous for altitude compensation and driveability.

My absolute favorite carb for all of my old Harley’s, pans, shovels, and ironheads, is the old 38 mm Round slide Mikuni VM—9. Although rubber mounted, it is easy to fabricate a support bracket from the float bowl to the case.

One could mill a flange like the press-on style used on CV conversions if desired. I dislike rubber boots on anything they come on after years of wrasslin' countless carbs in and out of hardened boots and dealing with cracks etc. When boots fail roadside fixes where practical are still a hassle.

Mikunis on HDs have few problems though (all of them I've ever seen were due to varnish, neglect or incorrect installation/tuning) because there is normally just one carb so I'd not fear running one on a looked-after bike like a chopper. I use nylon jets mostly because I inherited a box but they're easy to swap and the little jet cylindrical jet wrenches
quite handy.

Sudco Intl. Corp. - Carburetors