Freinds Bike 2001 Sporty Back Firing and dies.

[Hats2Heavy]

Looking for a little more insite here. One of my Bro's has a 2001 sporty 1200 carbed and he is having some real issues. Bike back fires every so often and sometime REAL LOUD. If he is on the throttle all sound good but shifting or at stops often then the bike will also die. Put new plugs in yesterday not much help there. Going for the propain gas trick monday. He also says it seems like the bike surches? Back and forth? Primary and belt is good. So any ideas, please post and I'll be back on this afternoon. PS I remember changing the jets on my sons 2003 sporster and poping off the cover to get to the main jet/ I don't remember the jet size I used/ I figure if we got to pull the Bro's carb off might as well get the jets right for his SE exh.

[Pirsch Fire Wagon]

Intake Leak

[andyxlh]

I'd agree with Tom, get a new pair of seals and put them in with a smear of washing up liquid to lubricate. also replce the 'o' ring on the carby.
Also might be time to replace the plug wires.
I had a coil do this on a car but not on a bike.
idle jet should be a 45 (stock on a evo big twin, the sporty comes with a 40 I believe) and the main - hmm- a 190 should be sufficient I think....but I'm mote than happy to be corrected on that one!
cheers
A

[WhipLash96]

That bike should have at least a 42 pilot and a 175 main with no major engine mods.