Farting sportster...

[Brigg]

Originally Posted by kevscrivener

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

Sorry Kev, I should read 'all' of the posted replies......

[dyna]

Originally Posted by 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

Yep that is true the pilot jet.. is what controls it the most.... I'm sorry but i don't get what you mean with lowering the the opening position of the butterfly valve. I mean isn't' that just normal idle control -- i.e. more or less open butterfly valve -- more or less rpm so to say? Or am I to much thinking like it was a car carb? Like a quadrajet or a SU ...

I assume you mean adjusting the main jet will adjust the fuel/air mixture, throughout the full throttle range. Adjusting the as in screwing in and out the idle adjustment screw only affect it at idle if I'm not totally wrong...

Cheers O & D

[dyna]

Originally Posted by kevscrivener

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.

I guess that is one of my next moves a little dust of propane around the intake will show it.. although I will start by feeling if it's tight.. Will check the exhaust side too although that should not affect that much if you have no mufflers at all which is basically what I have..

Cheers O & D

[dyna]

Originally Posted by 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 ?

Well we will see what it is in the end will we not

Cheers O & D

[dyna]

Originally Posted by OrangeR

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

[snip]

Here you go:
10 – Turn Ignition switch to OFF.


Cheers,


OrangeR (Ex Colin.....)

Thanks!!! will check that a bit later tomorrow or so..

Cheers O & D

[poplargreg]

Originally Posted by OrangeR

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.

Colin.....

That was the trouble with mine, exactly the same symptoms. Matts Machine Shop had two in (both 05s) in the same week with this problem. It would eventually get so bad when hot that the motor wouldn't tick over at lowish revs or pick up after the throttle had been rolled back.
A new sensor cured the problem. I took the carb apart about six times too, looking for the solution!

[harleyhigs]

Hi I'm new to the forum as well and I've got a similar problem! I've got an 06 1200 r, mine also when, starting up when hot has a bit of pre ignition! I've checked the fault codes and there is'nt any and there dosn't appear to be any air leaks either! any more ideas? ps it's got se2 slip ons and dyno jet kit but no free flowing air filter yet.
Thanks