Harley Davidson Forums banner

2005 Sportster Sputtering and Coughing

20K views 11 replies 6 participants last post by  hammer6315  
#1 ·
After some searching failed to show a solution to a problem like mine, I decided to bite the bullet and ask about it.

My ride is a 2005 Sportster 1200R. It has been rejetted for a Screaming Eagle "kit" by the PO. I have not changed anything besides maintenance items (tires, oil, plugs). It has 22k on it and is my "fun bike," and I use motorcycles for 90% of my transportation. I have used it for track days, and it garnered most of its miles (from 3500 to 20k) during a 8 month period when it was my only bike. During that time it was exposed to all manner of weather from sleet to rain to 15* commutes.

A few months ago it started having what I feel is a fuel issue. I had other bikes to commute with, and between field ops (Marine), family, and just plain laziness, I let it slide. It runs fine cold. Once warm it shows some hesitation during roll on, but nothing major. It's mileage held steady at around 50mpg. Power seems down, but that is just impression. The big issue is once I have her nice and warm and am in stop and go traffic. She idles fine, but on take off she sputters, coughs, and tries to stall. I can usually counter this by keeping her revved up to 2k rpm, and work through the sputtering to get a good rev up so I can get moving.

I am looking for solutions that may work. I have cleaned the air filter, plugs, and cleaned the carbs (see below for a note on this), as well as kept up on the scheduled maintenance (not looking forward to the 25k one). I have had the hint that it could be the "low speed" jet.

Note on my carb cleaning: While I am a maintenance guy and mechanically inclined, I am carb ignorant. I can take anything apart, clean it up and put it back together, but the exact workings of each part may elude me. I have done probably 30 carbs for bikes and none have been wrong yet, but that could be luck. Most of the time it is pretty obvious what is wrong with one. I still call myself a novice and helping others on their bikes advise them of such. So it is only fair that I question my own work as well.

Even if I am asked to redo some work, I want my baby back up to par. I have another track day on Sunday and while it is fun to abuse liter bikes on the tight course with my little CBR250R, I like doing it on the Sporty much better. It will be my last one for 3 years so I really want to take her and show the young guys that you can drag a knee on a 600# cruiser.

Can anyone help me out here?
 
Discussion starter · #5 ·
Alright, I tore apart the carb again, cleaned my battery connections, changed the plugs again to the cheap type Autolite's. Between those it seems to be about 90% fixed.

I put 50 miles on it and took it into town. Still did it, but much, much less. I will ride her to work tomorrow and see if she acts up again. I have noticed that now it tends to sputter more in slow corners.

I guess it would help to list the jets. I have a 180 and a 48.

I get to do track days as they are part of the military safety program. If you search YouTube for USMC ARTD you will probably get to see some videos. I go to every one. They aren't fancy, but they are fun and educational too.

Your sig says it XL1200R. I ended up with a hole in my muffler (Screaming Eagle II) and had to replace it. The new (to me) one is getting one now too.
 
Discussion starter · #10 ·
I found another issue before checking my codes and decided to pursue it. My starter was drawing way too much current. So with money being tight I found an after market one for $135 (1.4kw too) and swapped it in. 300 miles in and the sputtering is nearly gone for some reason.

I will pull the codes tomorrow though and see what I get and post that up too. The biggest thing I have noticed is that the bike seems really down on low end power still even though the sputtering seems to be fading. Is this a symptom of the crank sensor too? In a car I could see it retarding timing by way of safety default (limp home) to save the engine from damage if it didn't know exactly what the crank angle is for firing. That would do it for a car, but a bike I have no clue on.

Edit: Just pulled the codes since it was so quick. Sure enough P0374 and no others! Why no light? Oh well, another part getting replaced soon.