Is this making sense

Makes perfect sence, Mine does the same thing. If you've changed the air-intake, and not adjusted the Carb., there's your problem. The other option that I've come up with is your ignition coil (distributor cap). My bike started doing that and now it cut's off while I'm driving, subsequently busting my drive belt....I HATE belts!

Hey Art

[COLOR="DarkRed"]Many years ago somebody came up with the idea of using the needle from a 1998 XL1200 (N65C it's called) as a replacement for the stock one & if you look carefully, the taper is different. It's a bit longer too, but the point is it makes the transition sooner & faster. And more smoothly - look @ dyno charts - you'll never get a flat line on the A/F ratio, but the spike is gone & even the bump is gone - whole different ballgame.[/COLOR] Hey Art and that is why aI got the same C/V carb from a sporty years ago. on mine right now(still got an old thunderjet houssing stuck in the side,but the shorter needle is why I did it. Ancient HD-secret....

Hey Art

Hey Art and that is why I still got the same C/V carb from a sporty years ago. on mine right now(still got an old thunderjet houssing stuck in the side,but the shorter needle is why I did it. Ancient HD-secret....

Once you got yer carb setup like Art tells ya, make sure you got good fuel flow at the RPMs that your having your troubles. I had that prob with mine, ran great up to 100MPH and then sput cough fart. I took the petcock out and it was plugged up with old factory tank liner that was peeling.Let enuf fuel thru for low speed ,but starved it when I was usin it faster than it could refill the floatbowl. Then check your ignition system for loose grounds, when your revs go up could be shaking a ground loose and not lighting the candles enuf. If they're not lit you aint goin. Air,fuel,spark compression, got all them the sporty should be out there burin up the hiway. Good luck Let us know how you make out. Ya got a mechanical genius in yer corner(LSR holder) so I think your gonna come out just fine. :devil:

There is no intermediate jet in the CV carb like an S&S or Mikuni. There's a slow (pilot) jet & main jet, the intermediate range being controlled by the needle, which moves with the slide an S&S & Mikuni don't have. Tuned properly, the needle being a key factor, a CV will work every bit as good as an S&S or Mikuni & better if your ride happens to take you thru a lot of change(s) in elevation.

CV stands for "constant velocity" & the basic idea is to keep the *speed* of the incoming air the same all the time, even though the *volume* changes with throttle position & rpm. The CV has a butterfly valve like an S&S or Mikuni, but it's behind the slide & even though it opens immediately when you whack the throttle wide open, the slide in a CV has to move up before the carb can pass the full volume of air that it can.

Lots of tricks & gimmicks to make the slide move quicker, nearly all of which are counter-productive 'cause they make the slide "hunt" in normal riding. And every time the slide moves, so does the needle, which meters how much fuel comes out of the main jet.

What you see with a much lighter or drilled slide is it overshoots on the way up, then in a constant series of over-corrections, tries to find the right spot, but it never does. The jetting can be perfect, but the engine still not run right 'cause the intake velocity keeps changing & the engine is going back & forth between too lean & too rich as you're riding down the road, even when the throttle position is the same.

So to get the intermediate range right with a CV, 1st you have to get the idle & low rpm range right & then change or adjust the needle if necessary. Then you can fiddle with the main jet if it's not the right size. Once the idle/low end is dialed in, it's just the combo of needle & main that controls - if you leave the darn slide alone.

With respect to the CV adjusting itself to altitude changes, higher density air (lower altitude) moves slower, thinner air (like in the mountains) moves faster & since the CV carb is designed to keep the speed of the incoming air the same all the time, it will raise or lower by itself. And when it does that, the needle moving up or down along with it will change the amount of fuel that comes out the main jet.

So if the taper on the needle & the main jet are matched to each other, the A/F mixture will stay right, no matter where you are & I know guys who will see elevation changes of over 5500' on a daily ride. CV set right & it doesn't make any difference if you ride from the sea coast to the mountains.

The CV isn't as good as computerized fuel injection, but you also don't need to be an engineer to figure out how to get it to work right & the CV is a "set it & forget it" deal - once you get it right, you don't need to mess with it again.

With all the great information and advice given here (Art you da man, and I am so glad you see fit to explain all this stuff for us), I am suffering from riding withdrawls. I have heard folks refer to seafoam as snake oil, but a buddy of mine swears by it (others at it LOL). I added it to the fuel on the Sporty yesterday evening. Bike acted like normal for about the first mile or so, then I started to notice a big change in her responsiveness. So with a quick U I was off to my favorite local twisty hill. About 2miles of up hill twists and turns. The shame is it isn't one way and is only about a lane and a half. Not much traffic but everyone running on that hill thinks they are the only one on it no matter the direction they are going. I digress, enricher flush in, bike good and warm, I could lug the motor down pretty much in any gear and hit the throttle and she came alive (well about 3rd she got pissy but the hill is steep and 15mph in 3 up hill is stupid anyway). However, in 1st ol girl about tossed my rear off the first time I cracked down on her. All through the range on the throttle she was right there. No hesitations or coughs. Only once did she hickup and that was a long period of basically idle underload. Even that wasn't anything to write home about. VERY happy with her. Level ground ol girl would jump with ya. Before I had to use the frictionzone really to get it going. Now that isn't a problem.

I haven't given up on going back looking for leaks and such, nor going through the jets again, but for now while the rain is away I can local run her. Rain on the way and that will give me more garage time.

XLent !! I haven't used the "seafoam" myself, but I know others who like it a lot, including a very experienced outboard engine mechanic who says it cleans up the nasty deposits typical of 2-stroke engines (like an older Mercury outboard). So evidently it does work.

The transfer ports for the idle circuit are so small that even a teeny-tiny piece of dirt will mess up the low rpm range, cause the idle mixture screw to do next to nothing, etc., so evidently some trash in the carb was a major factor for you & now that's gone.

Well Son of a Biach!!!!!! I never mentioned that in this thread but my mix screw never did matter a great deal on performance. That I mentioned in my EARLY thread about this headache back in August last year. I could run it all the way in or dang near remove it and it didn't change things like folks said it should. I just thought it was me expecting too dang much.

If you don't mind Art I am planning to hassle you some when I get real serious inside this bike again. I want to bump her from an 883 to a 1200 sometime later this year. Didn't see the point until I had the 883 working like it should, no need to add more pieces to the puzzle until the ones I had were used up LOL. Thanx a million and like I said before this carb thing isn't over either, but sure is 1000% better than it was.

Glad to hear the bike's running so much better & I'd be happy to help you with the >1200 conversion if you decide to go that route. There are several ways to do it & some of them wrong, but several choices on how to do it right, depending on what you want the end result to be & how much you have budgeted to spend to get it.

- Art

check this

yrs ago my first bike i had a prob took me forever to figure out i thought it was carb too tgurn out after alot of trial and err it was my ciol lol just a trhought good lucjk

Finally jumped in on that carb yesterday evening. Pulled that badlad back off there and changed the slider to the new one. It used to backfire so badly it had burnt/melted the plastic on the original one. I noticed the needle was binding before it reached the C-clip so I opened up the needle hole on the old one and put it back in. That is where I started from yesterday. Pulled the old one out and put in the new one and dropped the needle one notch since I bumped up the jet.

Had a 170 in it, tried to put a 175 in but it is a yellin' chicken model and didn't fit in my holder well, and would bottom out against the bowl. Had to jump on up to a 180. Was scared it would be too much, but willing to try anything. Put it all back together except the chokecable cause I just knew I was going to have to pull it again and didn't want to fight that thing more than once. Fired the bike up and jumped on and the way we went. She was still warm from the ride home and it was about 75 out so I didn't need to choke it at all on the take off.

Rev limit hits about 40mph in 1st, about 65 or so in 2nd and dang if I know in 3rd cause it was going faster than I wanted and lots of throttle left. Major kick in the pants for that little Sporty. She isn't perfect yet and I still ain't convince that a 175 would be the better choice, but she is A LOT better again. She has a small hesitation when you crank down hard on her, but quickly gets over it. No backfiring or hickups of any kind. Just kinda a I ain't ready yet thing.

I rode her to a buddy's house and talked to him for about 3 hours or so. Plenty fo time for her to cool completely down. When I started her up I had to use the choke and ran it about 2 miles maybe. It had slipped most of the way back in on it's own since it weren't mounted when I went to close it. She was a bit cold natured for a few more minutes then she was right back to warm and happy.

I would hate to see what this little sucker would do if really and truly correct. I probably wouldn't need more than two gears the way I like to ride LOL.

Thanks for all the advice and input folks. It truly is appreciated. We ain't done yet but wanted to let you all know what was done and the outcome of it so far.

It is too much. Baseline for an 883 is a 165 & that's what most run best with. Stock on mine was a 160 which was too lean but a 170 was too much. 53 mpg & 110 mph before it started running out of breath too.

And as I've mentioned before, although the '04-up Sportsters have the newer style XB heads & the 1200 heads are different on the inside from earlier versions, the 883's are not. Larger cooling fins & different rocker-box setup yes, but combustion chamber & valve size no.

So what works on a '91-'03 883 with respect to the carb also works on an '04-'06. And I have never seen an 883 that needed a 180 main, including bikes that raced in the 883 Series when it was still around.

Your '05 may have the W grind cams (not sure about that) but they aren't enough "hotter" to require much larger jetting & I'd sure start with a 165.

Don't know what to say Art. I have had everything from a 160-180 in it. The only one that seems to give performance across the board has been the 180. I would like to try the 175 but, it physically won't fit so. The 180 has a day's riding on it. Dang my bad luck and crappy weather I didn't get to ride this weekend at all. Anyway, once I get back on it I will run her up to temp then run her up my hill and kill the switch while on it and coast into the drive and check the plugs. I don't have any smell of rich or smoke from exhaust but I will let the plugs be the final say. Then I will post back what I find, and start from there. Also want to see what the mileage does with this new jet. I really expect it to improve since I don't have to stay in the throttle to keep it alive.

Jets for a Dynojet kit, MIkuni or S&S carb will not interchange with jets for a stock CV. And the baseline for an 883 is a 165, which is what I've got in my '00 model, but as mentioned, although the heads on your '05 are different on the outside, they're not on the inside. 1200 heads are.

A little background: When I first got the '95 it was an 883 Standard with SE air-cleaner, SE I (Cycle Shack style) slip-ons with baffles removed & 42/175 jetting. Pipes sooty on the inside but @ the time I didn't know what jetting to use in a Sportster & got a 170. Still too rich. I also put the stock mufflers back on until I could find a set of baffles for the SE's - I know better than to run open pipes (except @ the racetrack). Down to a 165 main & by then I'd found a set of baffles for the slip-ons & the bike really came to life.

Got a couple CV carbs to play with & met a couple indy shop owners each with 40+ years H-D experience & got the baselines from them. And since there weren't any Sportster-specific magazines (& I don't much care about $60,000 custom choppers) I found the Sportster List on the 'net. Hadn't been actively involved in racing in 25+ years but I ran over to watch the guys run @ Maxton & the speed bug bit me again. Joined the Sportster List Race Team, put together my race engine project & also bought the '00 Sportster which started life as a base 883. Haven't coverted it to a 1200 yet, although I've got plenty of parts to do it.

So anyway, that's where I learned about what works in Sportsters, what doesn't & why. All the stuff I learned in college is great, but a lot of times what works on paper or calculator doesn't work in the real world.

Now I'm not sure if your bike came with the D cams or the W's & the W's would take a bit more main jet, but would not require a jump to a 180. If it was me, I'd have a 165, a 167.5 & a 170 to fine-tune with.

- Art

FYI I ain't trying to argue Art, just trying to make sense of this mess. More background on this bike. I bought it used from a fella in GA who bought it from HD Repo Auction. He had it all of 10 days before I picked it up. I have never had any contact with the original owner and have got no clue what he did to this bike. I do know what I can see from the outside (SE AC, Pipes) but no idea what's inside as far as cams and such. It honestly flat out starves for fuel with a 170, which leaves me wondering how a 165 could possibly do anything better for it. I have down to 150 in jets so dropping size isn't a problem.

I can see if I go back to the air leak then that could increase air thus needing more fuel and bigger jet. Or on the other side of that, fix the leak and reduce the jet size. Couldn't tell you if the 180 is blackening the pipes as they have been black from day one and yes I have been too dang lazy to clean them out along with the fact that every pipe I have ever seen has been black inside. I only get smoke when I start it with the choke out now. Once it is warm and running without choke, no matter how much I twist or how fast there is no visible black smoke from it.

I'm wondering did he put a Dynojet or other aftermarket carb kit in - the fact that the 175 jet you've got won't fit indicates that. Or maybe where you got the 175 they gave you the wrong one - pour some stock CV & other carb jets out on the table & at 1st glance they look the same. But even though I've never used the Dynojet kit, I know the threads are different - I think they're the same as Mikuni, but they won't screw into a stock CV & a stock CV jet won't screw into a Dynojet setup. And the S&S carb on the race engine takes Mikuni jets.

Best way to find out what you got is to get the parts manual or borrow one, see what the stock parts are & compare to what you've got. Kits like the Dynojet change the emulsion tune & needle too - they're not merely bigger slow & main jets. The numbers are different too - i.e. a 175 for the S&S & a 175 for the CV do not flow the same amount of fuel.

Oh yeah, if you've got an air leak that'll sure mess things up & you'll never get the jetting right. And I've seen little leaks that'll have you scratching your head - like a minor one where the intake manifold meets the heads that goes away as the engine heats up 'cause the parts expanded enough to close the gap down. Go to start the bike after it's cooled off & the leak is back. And once I didn't get the seal where the carb goes onto the intake manifold set right - thought it was & the bike ran, but it didn't run right. Doesn't take much of a leak to mess you up.

Hopefully that will help you narrow it down. I'm sure it's nothing serious, just real aggravating :gah:

- Art

I have two of the emulsion tubes as well. The original (maybe not factory but one in there when I got it) has small holes along the length of the tube (needle section), the other in there now does not have these holes.

As for the 175 looking the same it does not. The ones that fit both tubes are maybe 3/16th in diameter, while the 175 is more of 1/4 or 5/16th in diameter. The threads are the same. The oversized diameter on the 175 keeps it from seating down in the emulsion tube like the others do. This leaves the entire setup too long and the bowl bottoms out with 1/8th gap of flushing up. NO Flippin what that will work.

I have fought this rascal since August of last year, trying different things. I will not give up on it and I will beat this problem. In the mean time I have already racked up better than 2000 miles on my problem child. Not like I can't ride, just not getting what I should for my girl. I know it will all work out and someday I will be able to say I did it. (with help of course, but I will beat it)

What I've always done when I got so far away from the baseline that I wasn't sure what change was doing what anymore is start all over again @ the known baseline (& take better notes). The indy shop owners I know do too, when somebody brings in a bike with a Dynojet, Thunderslide, et all - factory CV parts, no gimmicks & then only adjust one thing @ a time. Still get the urge to tinker & try something else, but not wholesale changes.

Another thing that comes to mind is the needle & from what I've seen from guys who have '04-'06 Sportsters, the stock one works best. The old N65C works better in my bikes, but not in the newer ones. A couple guys have added a shim or even 2 for fine-tuning, but no lighter slide spring or any of that.

Hey Art, did some reading last night. I have a surprise for both of us now. Got in the fuel system section of my HD service manual. Page 4-1 has a little chart of Jet Sizes. Dig up on this: