Farting sportster...

[dyna]

Hi,

I'm new to the forum but I had Sportsters since 2003 so it's been a while. It's all been US domestic once since I used to live there. Anyways the last (and only) Sportster is my 2005 (my) 1200 roadster, and its the one I have issues with. I bought it second hand back in late 2005 (i.e. when the new my 2006 had come out). It had something like 2000 miles and he had done the mandatory HD service.

The first owner had also installed a Screaming Eagle type exhaust, genuine Screaming Eagle air-filter kit and some type of generic jet kit.. The bike was running very well when I got it and even ran well when I got it over here too.

However when I been here for about 6 month if you rode it on the freeway in say 65 for a long period (more than 20 min). It would fart (spit and hesitate at low rpm) and run not that well. However since I didn't ride it on the freeway that often I didn't really take action since the bike generally ran well around town and on country lanes.

However this sping start it didn'r run well at all. It's been standing for quite a while (August to May or something). So I did the normal stuff, cleaned the carb (taking it off the bike and cleaning it manually with carb cleaner). Put the adjustable idle jet two turn out. Slow jet is 45 and the main yet was 175... I put new spark plugs and a new screaming eagle air filter since the old one had disintegrated.

Start up the bike and it runs pretty ok until it get warm when it when you take it from idle to 2000rpm spits and farts and it had a serious tummy bug. I adjust the idle jet to three turns out.. (i.e. one more). I also change the ICM to a screaming eagle one (31785-04A). The bike is now runing better but not good but the farts are less frequent. The farts are as usual only when warm.

I then change the main jet to 185 and it gets better again. The symtom are:

1: It only happens when the bike is warm
2: It spits and farts when going from idle to 2000 (when you take of from a traffic light)
3: It spits and farts if you engine break and then take on throttle.
4: If you coast on a high gear below 2000 rpm the engien will kind of die and not run.. If you give throttle twice you can kind of get over the 1000-2000rpm barrier of farting
5: It doesn't idle that well either..

Any takers what I should do now (don't have any bigger jets -- have smaller). I pretty good with cars and been restoring a few of them (frame off - total restorations so I know my way around a carb). However bikes are very alien to me .. heck if a car run this bad there would be something seriously bad with it..

Cheers and big thanks in adv
/O


PS: The bike now has 5500 miles and I done the services my self.. ah yes the acc pump is working just fine squirting down the throat of the carb..

We live in Sutton -- so if somebody know a good HD guy around there where I can take it that would be super too..

[OrangeR]

Originally Posted by dyna

Start up the bike and it runs pretty ok until it get warm when it when you take it from idle to 2000rpm spits and farts and it had a serious tummy bug. I adjust the idle jet to three turns out.. (i.e. one more). I also change the ICM to a screaming eagle one (31785-04A). The bike is now runing better but not good but the farts are less frequent. The farts are as usual only when warm.

Have you checked the speedo for error codes?

I believe 05 bikes have a problem with the crank position sensor failing which gives symptoms similar to yours and only when warm. The sensor is quite cheap to replace if it is at fault. I'm not 100% sure of the error code but I think it's P0373 or P0374.

I hope this helps,

Cheers,

Colin.....

[Tone]

Hey Dyna can't offer you any help with this, but I have exactly the same problem & symptoms as you describe.

2006 xl1200r with screaming eagle slipons & s&s air filter

So far done the new plugs, cleaned & oiled the air filter & given the carb a good squirt out. Stripping & cleaning the carb thoroughly was gonna be my next step. I'm wondering with mine if its not a fuel/air problem then it may be somthing electrical such as the crank position sensor on its way out/breaking down when hot, is that feasable ?

It does however feel like a fuel delivery problem rather than an ignition problem, but I am no expert & this is my first dealings with this sort of thing on a Sportster. Could do with a few pointers myself so I will follow this post to see what advice is given. Meanwhile if you solve the problem please update your post with the info. Any advice please anyone ?

[Phil]

You will hear this a lot, but check for vcuum leaks between the intake manifold & the Heads.

Also check & clean all the battery connections.

[dyna]

Thanks for all replies!

Not checked for error codes.. actually don't know how to check it... It's not in the service manual, is it described in the electrical manual? Is there a scanner you can buy for some modest sum?

The battery is new so it's clean so to say. Crank sensor makes sense, if it's not expensive I can just change it for the heck of it.. Will check the price today..

I might add that it doesn't happen 100% of the time, it comes and goes. However the warmer the bike get the more frequent it gets too..

Cheers Dyna

PS: Don't hear any leaks, but then that is pretty hard to hear. Guess I need to spray with some gas or similar to detect it..

[kevscrivener]

Originally Posted by Phil

You will hear this a lot, but check for vcuum leaks between the intake manifold & the Heads.

Also check & clean all the battery connections.

What Phil said. Just 'cos they're rubber mounted does NOT mean things can't work loose in fact IMO it's even more necessary to check for stuff loosening off; being lulled into a false sense of security due to lack of vibes was the downfall of many a Norton Commando owner!

Battery connections don't just work loose BTW they can sprout a hairline crack which is all but invisible.

[OrangeR]

Originally Posted by dyna

Thanks for all replies!

Not checked for error codes.. actually don't know how to check it... It's not in the service manual, is it described in the electrical manual? Is there a scanner you can buy for some modest sum?

The battery is new so it's clean so to say. Crank sensor makes sense, if it's not expensive I can just change it for the heck of it.. Will check the price today..

I might add that it doesn't happen 100% of the time, it comes and goes. However the warmer the bike get the more frequent it gets too..

Cheers Dyna

PS: Don't hear any leaks, but then that is pretty hard to hear. Guess I need to spray with some gas or similar to detect it..

You may as well check for the code first as it's free!

Here you go:

Speedometer Self Diagnostics: The speedometer is capable of displaying and clearing speedometer, tachometer, TSM/TSSM and ICM/ECM Diagnostic Trouble Codes (DTC).

1- Turn Ignition switch to OFF & Run/Stop switch is to Run.

2- Push odometer reset button in & hold.

3- Turn ignition switch to Ignition and release odometer reset button. Background lighting sould illuminate, speedometer needle should sweep its full range and indicator lamps (battery, security, low fuel, check engine and cruise) should illuminate. The word “diag” should then appear.

4 - Push the odometer reset button once and you will see the selection menu "PSSPt" with the first P flashing.

5 - Each letter represents an area of the diagnostics module. The module that is flashing is the one you are going to check. To move from one letter (module) to the next, you push the odometer reset button one time. (from P to S to SP to t and back to P, etc.)

P = ECM/ICM (Electronic Control Module (EFI) / (Ignition Control Module, 'Carbureted')
S = TSM/TSSM (Turn Signal/ Turn Signal Security Module)
SP = speedometer
T = tachometer

6 - To get the DTC within an area of diagnostics, push and hold the odometer reset button in for 5 seconds and release. If there are any DTC’s the code will be displayed or the word “none” will appear if there are no DTC’s. Push the odometer reset button again to view additional codes if they exist.

7 - Record the codes.

8 - If DTC’s are not to be cleared, Press and release the odometer reset button. Part number of module will be displayed.
NOTE: To determine if a code is current or historic, clear the displayed code by pushing in and holding the odometer reset button ( longer than 5 seconds) until 'clear' comes up.
Release the odometer reset button. Turn OFF the ignition switch. Run your bike and shut it down then recheck the DTC’s again by repeating steps 1 to 9.
If the code is current it will reappear.

9 – Press and release the odometer reset button to continue to the next module.

10 – Turn Ignition switch to OFF.


Cheers,


OrangeR (Ex Colin.....)

[sKorch]

any problem at low speed is normally down to the pilot jet or throttle opening position.
altering the main jet will make no difference to the low revs you mention.

My 2002 883R still farts even though I have lowered the opening position of the butterfly valve.

The problem seems to be to balance the amount of petrol that its sent into the carb via the accellerator system against the amount of petrol sent in via the butterfly valve(which controls the amount of lift on the needle) at low revolutions.

people have mentioned adusting the fuel/air mixture, but I think that may affect your petrol intake throughout the full throttle range.

Since I'm getting over 60mpg with my current settings I'm more than happy to put up with the occasional spit-back.

not a very technical answer to your question I'm afraid, but every bike and the way its ridden means there are so many different settings for your own way of riding that it will be almost impossible to give you a definitive answer to cure your problems.

hope this helps

see ya

[Brigg]

Similar problem, found to be the rear cylinder exhaust header pipe nuts had come loose. Once tightened the engine runs sweet as a nut...
Just a thought....!!!

[kevscrivener]

Originally Posted by Brigg

Similar problem, found to be the rear cylinder exhaust header pipe nuts had come loose. Once tightened the engine runs sweet as a nut...
Just a thought....!!!

That's exactly what happened to mine, and prompted my comments above.