Sporty carb

I got the manual for my daughters sporty today , I need to attack the carb 04 883 she got it used from a dealer , someone changed the pipes & put the SE ac kit the DAs at the dealer said it was fine like that , it bog's a little from idle or if your running & twist on it then pick's up , this biik don't tell anything on how to adjust it except the idel screw , so out come the drill & I drill the cap to start & loose the bog down , this is going to be fun , the last carb I did was on my old shovel & it was a bendix

Hi Cowboy,

The service manual doesn't give any carburetor adjustments other than idle because they are required to keep it sealed (EPA). You'll find this carburetor is much different than the earlier Bendix carbs. Here's a couple of articles to help get your daughters carburetor running correctly without too much modification.

Harley Davidson Carburetor Performance Tuning
and
Harley Carburetor Jetting

Ken, Thank's I was going to try & wing it , Like the old day's But I know these ears don't here as good as they use to

CV (Constant Velocity) carbs are pretty straight forward.

If you have drag pipes dump them they cause more problems on tuning a carb, a good set of slip ons will make your life easier.

At least be sure they have baffles.

Drilling out the cap over the screw is good, be careful when seating and turning it back out not to overtighten

Don't ever drill out the hole on the slide, a major screw up that is done by many.

Usually the main jet is fine as EPA doesn't give a rats butt about WOT as we rarely run there.

The pilot jets are close, you may need one size up but It's doubtful.

Usually a simple idle screw adjustment will fix it up.

hrk...."Don't ever drill out the hole on the slide, a major screw up that is done by many."......im curious on your thoughts on this....thanks!!

HRK , thank's , Ken posted those links & I have read up on these style carb's
Her Bike has the SE slip on's with there baffles & the SE air cleaner kit
The link ken posted show's to drill on the bottom ,
I will try the fast idel first then go from there

chuck

seems like everyone that has done it ends up complaining about poor carb performance, it changes the timing on velocity needed to raise the slide based on the pressure.

Everyone is looking for better throttle response but you have the chance of going backwards performance wise.

Some smooth the side rails, some clean them up with polish and smooth the front edge which is fine

JMO the carbs are good the way they are, usually tuning is the key

If you want it modified see Bobby Woods he does a lot of changes that have been tested to work.

thanks for the reply....just gathering info and opinions. the cv carb is a good one and i like mine. i guess i have run most all carbs from linkerts to cv's,,,the worst one i had was a webber.......never could get it to run correctly on a 74 shovel..........

For all the carbs out there, unless JMO you really have a significant difference in the motor the stock cv40 is a great carb, for shovels, sporty, evo to twin cams it can handle a pretty good amount of power.

Most folks get caught up in the carb war, almost like an oil war LOL

I have bought and sold

CV44
CV51
HSR45
Super E with and without thunderjet
Super G with and without Thunderjet
Woods Rebel 505 (CV51 Modified)

So far the best MPG and torque curves are in the cv line with the woods topping them all, then again it's on a 124, it's bigger than the G I have now which runs well.

Getting them dialed in is the trick.

Absolutely agree, many drill out the small hole (vacuum port) on the slide and end up suffering. A small amount of drilling is okay as long as you keep it at or below 7/64" which is only a hair larger than stock. Drilling the hole to 1/8" only works on lighter bikes that love signal to signal drags. The mistake comes when you drill that port 1/8" or larger on a heavy bike or one that's used in daily low RPM commuting. Because the slide is controlled by vacuum it can actually open too fast which leans out the intermediate circuit. Another condition of over-drilled slide ports is what I call slide shudder. This happens when the slide opens quickly, then attempts to close again under light load. This becomes a rapid bouncing action that in turn will cause popping. Lighter springs can help compensate for this but unless you use the right combination you can actually make things worse.

I cringe when I see a carburetor that has the slide hole drilled out with a 5/32" bit where the port looks as large as the center hole (where the needle protrudes). These same carbs often come with multiple washers shimming the needle, probably to counter the effects of the slide which can't make up its mind whether to open or close

Anyway, after many years of building carburetors I personally believe the CV is about as good as motorcycle carbs could get for real riding before making the step into fuel injection. While there have been plenty of hi-performance carbs come out there's never been another on the market for our v-twin engines that can self-adjust to changing load and elevation like a CV.

Thats just my humble opinion (JMHO)

thanks to both for the replys.......

Thank's to all , I just learned a lot , What I was refering to was the drilling out the cap for the adjusting screw , But got a good read & A lot of good info on the CV carb
I got to mess with the sporty last night , After taking off the AC witch turned out to be stock with the SE cover plate on the out side cover to fool us I just tryed to idel screw at first , & so far so good I starded out one way less the a 1/4 turn , I no good , so went back the starting point ,& each time less then a 1/4 turn at a time & retesting after each turn after A little over half way to a full screw turn she seemd to run better & no boog down I will double check it all today & go from there