I have been chasing the right jet/needle combination for a second riding season now, and I am just about ready to give up....

I have quite literally read every post there is on multiple forums about carb farts and jetting and needles, and have tried everything, with diminishing returns. I am wondering now if the carb is fine, and I have some other issue - coil, timing, throttle cable adjustment?

I am the second owner of an '05 883L which came with aftermarket slip-ons and stock jetting/air cleaner. When i bought it, I had to use the choke excessively to get it warmed up without backfiring through the carb (farting), and even when warmed up for 30+ minutes, it would still fart from a red light or when reducing to a slower speed and continuing on, like in a sharp turn.

Last summer, I put on an old school bugs eye air cleaner to open it up, and re-jetted the carb with the CV Performance needle and jet kit/instructions. I followed their recommendations of a 44/175 combination - farts stayed the same with no improvement. Mixture was around 3 turns out and plugs looked perfect. I did not drill out the vacuum hole in the slide next to the needle.

After reading a bunch of stuff online, I then tried a 45/180 combination. Farts were less - but not eliminated - but I was running so rich that I no longer needed to use the choke at all to start, and even with the mixture screw almost all the way in, I was too rich and the plugs looked awful, all black.

I went back to the 44/175 and just lived with the farts. After a few long rides however, it started to choke and almost stall when I was giving it gas in 1st when the light turned green. The throttle would be unresponsive - I could not get it to do anything when I blipped the throttle or when I rolled the throttle like usual when letting the clutch out and trying to take off in 1st. It would just stumble, sometimes fart, or it wouldn't respond at all to any throttle input - but it never stalled either. It would take a few attempts at giving it throttle before it would behave normally and take off into 1st.

This year, I tried the jet/needle configuration suggested in the Sportster Performance Handbook by Buzz Buzzelli. I drilled out the vacuum port hole and put in the stock 42/170 combination, but put in a 27094-88 needle from an 88 Sportster. This is the needle from an older CV carb before they had an accelerator pump, so the needle runs more rich. The mix is about 3 turns out. This was working pretty good - it will still fart occasionally, but my choke use seems normal and my plugs look good - kind of grey/tan. However, the same problem is occurring again when I have been out for a long ride and come to a red light - stumble, unresponsive, barely able to get going in 1st, but never fully stalling.

I noticed today when it did it, that as i came to a stop at a red light, it was idling fine, but as I sat there not touching the throttle, the idle dropped slightly, and then all of the crappy symptoms began and i could barely get it to take off. At the next red light, I made sure that I gave it a few tiny 100 rpm throttle squeezes to keep the idle from dropping. This worked, and I took off normally. My idle is set properly and is not not excessively low or anything.

If you have read this far, thanks for sticking around so long. I am really at the end of my rope with this bike. I am not sure what else there is to try with the carb as far as jets/needles go. I am now wondering if it is fuel related, but at another spot in the chain. If anyone has any advice or a similar experience, I would be very grateful for any help.

Thanks,
R

 

In all this time did you ever check or replace your intake seals?

 

does your carb have an accelerator pump that squirts a shot of gas into the venturi as you open the throttle ? If so , is it working?

 

edit,his thread leave it at that.

 

Some people should make their own thread instead of side tracking others and confusing things

 

Can do,but figured there have been so many carb threads lately why not just jump in one.

 

have you taken it to a Shop??

Also if that doesn't work out, get a closer to stock exhaust and put the stock AC back on. or just return it completely to stock.

 

Accelerator pump works fine. I put a new manifold seal on and tested with an unlit propane torch - last year and this year - with no leaks found.

I am getting to the end of my rope and may have to resort to taking it to a dealer. There aren't any indy shops in my town and I usually do most of my own work, so a dealer is really a last resort. With carb/fuel system issues, i have never had a persistent problem like this before. I want to trouble shoot as much as I can before I have to pay a dealership $80 an hour to do the same things I have already done. I have spoken to a dealer generally about carb jetting and got lots of dumb looks. They seem to be used to the EFI crowd who can't manage their own oil changes, let alone a carb adjustment. This is why the dealer is my very very last option.

 

Honestly, carb problems are something I really hate to work on. Namely because everytime someone brings a bike to me saying the carb is the problem it is 9 out of 10 times NOT the carb that is wrong.

Those things will run ultra lean and super rich without giving too much trouble. Unless you're under 11:1 or over 16:1 AFR they can be pretty tame. I've seen more **** than I care to deal with when it comes to carbs.

I've got a CVP kit, and the recommended 44/175 sounds like your bike is an 883. I had to go with a 42/175 on mine because the given 44 was too rich. Everyone is different.

It's possible your CKP is bad as well. That has shown a lot of issues that present as bad carb tuning on the 04-06 models. It could also be an intermittent ignition module problem. The shitty part with these is that it requires replacement and test to verify if that is the problem.

Now you see why us mechanics end up charging $80/hour (or some really nice beer) to get this **** done.

 

Take it to a pro. Be sure to tell him you Mickey Moused it from stock, so he doesn't waste time figuring that out.