Hello all.

So this may be lengthy, but I want to try and give all of the info that I can so I can try and get a few things figured out. I bought a 1997 Sportster 883 Hugger with about 3000 miles on it. I am the third owner. First owner was a woman who rode it for about 2600 miles. Second owner only put 400 on it.

When I bought it, the second owner has some cheap short slip on mufflers and a garbage air cleaner assembly on it (no hard mounts to motor, so carb would fall off with a good carb fart.) He stated he had never had it rejetted.

When I rode it as I bought it, it would fart through the carb, as do most sportsters. I attributed this to no rejet with the intake and exhaust, and possibly dirty carb.

I purchased and installed an Arlen Ness big sucker (to replaced the crap after market air cleaner) and V&H short shots. I know they are not the best performing pipe for the bike, but I love the look and the sound, so these are what I installed. Not looking to win any races. Standard loud baffles installed.

I purchased the CV performance tuners kit with the EZ adjust mixture screw and set off to clean and rejet the carb. My book says that stock 883 jetting is 42/170. When I opened up the carb (aside from being dirty), the jets were 45/180 which (if I am not mistaken) is the jetting for a stock 1200. Bike has stock 883 jugs and it appears they have never been off so I know a 1200 kit was never done on the bike.

I rejetted to the stage one specs listed in CVP, which is 44/175. The float was also way out of wack based on my manual. According to the manual, with the carb tipped at 15-20 degrees, float should be about 0.4" (+/-) from the bottom of the carb surface. It was at least 0.5". So I also adjusted that. I installed the CVP emulsion tube as well and drilled the slide as specified in the kit. New NGK plugs gapped around 0.04ish (memory) were also installed.

Threw everything back together and fired up. After playing with the idle screw adjustments, I had to be 3 turns out before I could get it to stop farting and run decent, however it would still idle not smooth. From what I understand the idle is supposed to be a nice "potato potato potato" idle, and this is actually more of a "horse gallop" when it idles. (do a horse gallop with your hands and you will know what I am talking about) Took a ride, and it would still fart occasionally and I get the exhaust popping upon deceleration. This led me to believe that I am still lean on the idle mixture. I bumped the idle jet up to 45 again (i know not a big change) and have played with it with limited success thus far. Still get a fart sometimes...still get decel popping. I also seem to get a bit of break-up as I throttle up slowly through the gears. Its not a super smooth transition. If I hammer the throttle, its all there and powers right through the gears no problem. But if I ease into the throttle, it almost seems like it "misses" slightly. That may not be the right term.

I did the propane test with the intake to check for vacuum leaks but have not found any. I ordered all new gaskets anyway since I have heard people were still unable to find them but had them. I have also ordered a new CV slide because I did notice a burn mark on my slide, which could have ill effects on the throttle response if the rubber is damaged. Also on its way are new spark plug wires.

So...thats it in a nutshell..haha. My questions are as follows:

The idle...is the unsteady "gallop" idle normal, or does it sound like a possible spark/coil issue? What would make the idle not be steady? Could the timing have jumped? (does that happen?)

Hesitation/miss...could this be a result of a bad slide due to the burn? Or is this a jetting/spark issue as well? Again, I pulled a 180 jet out of the bike and installed a 175. 180 seemed big to me for a stock 883. I live in Connecticut so I dont know what effect my altitude is having on my jetting.

General Jetting...Did 45/180 seem like a lot for a stock 883? Has anyone else run into this setting on their bike?

Exhaust/Intake...is the combo ok for this bike? Again, it is an 883, and I am aware of some performance issues with the short shots, but its better than what was on there before.

Again, this bike is 20 years old with no work done to the bike other than what I have mentioned. Other then speedo, the electronics are all stock. I am not sure if the coils or ignition modules go bad but going weak or just fail, but I guess it is a possibility.

Sorry for the lengthy post, but every time I read a post, the first reply is typically "we dont have enough information". So I gave you everything.

Thanks again..all comments and info are appreciated!

 

45/180 is not out of whack for an 883, I'm running a 45/175. Did you flush out all the idle passages with carb cleaner and purge with compressed air? Take out all the jets and mixture screw first.

Is your needle diaphragm functioning? Not pinched, torn, etc.

2.5 turns out for idle mix is usually a good starting point. Make sure your o ring, washer, and spring are installed correctly. Check to see the old o ring is not still down in the mixture screw hole.

I just did my carb, changed manifold seals, etc. It was 27 years old and now runs like a new bike. You can do it.

Idle speed should be about 1050 RPM, not too low or you'll starve your top end for oil!!! Sportsters like the be revved up, too!!!

John

 

When I cleaned the carb, I did flush all of the passages. And I blew them all out. When I replaced the Idle mixture screw, the oring was still inside the port, so I just placed the washer and spring back in as they came out. I had not ordered these with the kit as I told as long as you dont lose them they should be fine.

I will try 2.5 turns out with the 45 idle jet and see where that lands me. Unfortunately without a tach, I dont know how to measure my RPM.

Would the break-up or hesitation at mid range be from too small a high speed jet, or spark?

 

Hello Blacksport97, I too am having low running cough issues...I know this is a 3 year old thread, but I would like to add my thoughts:Hello all, hope you are all enjoying the lockdown and getting out for a social distance ride out. Anyway, I thought I'd document my experience of the infamous low rev, idle cough of my 1990 Sportster. I have had the bike since April 2017, but it has always had this ****ling low end cough. Having a Suzuki GSX750F, I was at least getting out, but wanted to ride the Sportster. I decided to investigate further. The sportster, being 30 years old and 9 previous owners, there were other things that needed sorting. But the cough was the main thing. It has a Supertrapp 2 into 1 exhaust system (not sure of model), Compu-Fire ignition system and I have changed the air filter to a model similar to the S and S Stealth as the old one which was a tear-drop sponge type element and was disintegrating. Anyway, took carb apart, checked jets (44/175), cleaned channels and checked float level and put it back together. Drove it to work over 2 weeks and noted it's characteristics. Choke out when cold, starts fine....couple of minutes and choke back in, idles fine. But as you pull away...cough, maybe once or twice. Runs fine, accelerates fine, however, on cruising, I could hear popping. I then ordered the Custom Chrome carburettor kit ‘15799’. Took carb apart and replaced all seals and gaskets that the kit supplied. I did notice the intake seal was a little large. Anyway, put it back together and sure enough...no idle at all, it would only run on choke (enrichment). It appears that the inlet seal is allowing air past. I then got my calipers out and measured the inlet manifold (50.00mm). I measured the carb throat that goes into the seal...45.85mm. So there is a gap of 4.15mm that needs filling, or 2.075mm per side. I then measured the inner lip of the seal on my original seal and it measured 1.75mm….hmmmm, not really enough, possibly why it was coughing originally. Then I measured the new seal from the kit….1.40mm oh….that's why it wouldn’t even idle – air getting in. So I surmised that the quality of the carb kit is in question. I have ordered a new seal and waiting for it’s arrival and will measure. So my question is, has anyone else looked at this and what are your findings… also has anyone got seals kicking about their garage that they could measure and see what you have? I’m looking for at least a measurement of 1.8mm or more, so that the fit is tight. Obviously over 2.00mm may be too much. I hope this esteemed community can shed some light on this. Safe riding all….

 

Did you look at your plugs since you went through the carb?

I installed the same CV Performance deluxe tuner kit on my 1997' 883 and followed their instructions and jet recommendations to a "T". My bike has an RSD Vance & Hines Tracker exhaust and a Screamin Eagle Stage 1 air cleaner. After dialing in the mixture screw the bike starts great and seems to run really well. After putting a couple hundred miles on it I will say that I get some popping on decel and occasionally on decel when rev matching the downshifts by blipping the throttle I will get a carb fart. I pulled the plugs and they are nice and brown so I am going to leave it alone and just ride it! G.B.

 

Hello 'gone blue', yes but they are a bit black, but understandable, given that it probably is a bit rich to compensate for the extra air it's getting...

 

I measured a spare seal, 46mm inside, 57mm outside.

John

 

OK, I bought an 03' last year that was hard starting and had a take off cough. I took the carb off and took it apart for cleaning and examination. I found that one of the previous owners had put in a Keihin stage one kit (45-165 with a NKOH needle-Keihin's answer to the no longer available 88' XL 1200 needle). I used the CV site recommendations and put a 170 main in, drilled the slide as recommended and shimmed the needle up with one washer (.024). Installed the easy idle mixture screw set to 2 1/2 turns out (changed later to 2 3/4 turns). Bike coughed a bit on throttle snap which is why I turned the idle mixture out another quarter turn. Now starts nicely, idles smoothly when warmed up, no cough on acceleration and no popping on deceleration. I am at about 3600' ASL.....have de-baffled OEM exhaust, K&N type air filter in an OEM housing (a poor man's stage 1). All seems to be well.........

 

Thanks John, my two measure 57mm/46.5mm and 56mm/45mm. However, these dimensions will change when it has been pushed onto the inlet manifold. I believe the important dimension is the inner lip. If you look at the seal where the groove runs round...measure the inner rim, that’s the bit that has to fill the gap between the ally of the inlet manifold and the ally of the carb body. If this is less than 1.70mm – I know it can only be a rough guide - so long as you measure lightly, you should get some idea, it will probably let air in. What do other think? I was going to insert a picture, but I haven't shrunk it yet. Next time.

 

Hi All, so I'm now going through the procedure of replacing the manifold to head seals. What I found confirms my suspicions regarding the quality of the Custom Chrome kit I originally bought. As you can see, this first picture has the two different seals.

this picture has the two different seals.

...excuse my attempts at constructing images and text...but I'm keen to get my thoughts across. I shall post the next stage in my findings soon.