rough warm up

[jjz28]

My bike 79 xs1100sf special runs really good after warmed up but runs rough until then. I seems like it only runs on a couple cylinders at a time. Its fine after it warms up. It seems the choke/enricher doesnt really work either. I cleaned the carbs but just learned of the hole in the bottom of the bowl. Is it probably those ports in the bottom of the bowl? Also, i didnt take out the emulsion tube because i didnt know it came out. i guess i could clean both of these by just taking the bottom bowls off couldnt I? How do the tubes come out, just pull? Thanks.

[crazy steve]

The carbs pretty much have to come all the way apart to get the emulsion tubes out...

More info here....http://www.xs11.com/forum/showthread.php?t=36017

[jjz28]

thanks for the quick response steve and the link.

[jjz28]

Ok, so I have the early carbs right? So, I should set the screws at 1 1/2 turns from seat? Mine still have the caps on them so i didnt even take them out or touch them. Thanks.

[DGXSER]

If it were my carbs, I would pull those mix screws and make sure all of that is clean as well. Also, be very gentle and only LIGHTLY seat those screws. The tips can easily break off in the holes if over tightend, and many a fine carb has been butchured trying to remove the broken tips.

[ddragon63]

If it were my carbs, I would pull those mix screws and make sure all of that is clean as well. Also, be very gentle and only LIGHTLY seat those screws. The tips can easily break off in the holes if over tightend, and many a fine carb has been butchured trying to remove the broken tips.

+1 Unfortunately I resemble that remark... you don't wanna to have to invent stuff because you had a broken mixture screw and had to get it out the hard way.... I now own a custom modified mixture screw that only fits in #2 carb. You don't wanna have to go thru that. Be gentle with those little sewing needles @ the bottom of the screws

[jjz28]

mine still have the caps so they should still be good right? Noone should have been able to screw them down and break the tip off in the hole with the caps on? Also, is it 1 1/2 turns from LIGHT seat? Thanks guys. I do search but i also want to be sure i understand.

[ddragon63]

book says 1.5 from light seat... theres no caps on my 79 sf the screws sit exposed above the carb body. What year carbs do you got?

[crazy steve]

book says 1.5 from light seat... theres no caps on my 79 sf the screws sit exposed above the carb body. What year carbs do you got?

Your caps have gone missing... All the '78-79 carbs had the plastic caps as OEM (federal smog standard), but most have disappeared over the years. Generally, if you find those the carbs are unmolested.

[ddragon63]

Early carb should look like this... I think the 80 and later carbs were capped... but I may be mistaken

[motoman]

book says 1.5 from light seat... theres no caps on my 79 sf the screws sit exposed above the carb body. What year carbs do you got?

He must have 80 and later carbs, which is a whole different setting for EVERYTHING.

[ddragon63]

Your caps have gone missing... All the '78-79 carbs had the plastic caps as OEM (federal smog standard), but most have disappeared over the years. Generally, if you find those the carbs are unmolested.

see... the smart guy is faster than me

[crazy steve]

The '78-79 carbs looked like the lower set in this pic...



These still have the OEM 'smog' caps on them. These would allow about 1/3 turn of adjustment from stock. The upper set is the later carbs; these came sealed (again, reflecting tougher smog standards) and you have to remove the seal to access the idle screws.

If the plastic caps are in place, your idle screws should still be good. You still should remove them and clean the passages though...

[jjz28]

Those are the carbs i have but my screws have caps on them, they are the original carbs im sure. My bike only has 12K on it, i think most people take those caps off and then have the screw exposed like yours. Mine is the bottom carbs on the pic.

[ddragon63]

I do want to take this opportunity to state that 1.5 is a guideline.... not 2 carbs are the same. you must tune them in. the furthest one in on mine is #3 and its about 2.25 out and it still idles lean. Sooooo don't hold 1.5 as gospel