New here , just snagged a 1980 xs1100

[tarzan]

TDodge7 wrote,

tarzan , this is a 1980 , i don't think i have anything adjustable on these aside from float height , everything is still capped .

Actually you need to drill the brass plugs out to get to the screws.You want to be carefull though so you dont bugger up the threads.
BTW,I have a 1980 also and I drilled mine out.I have drilled several sets of SG carbs I have rebuilt.
If you soaked the bodies in cleaner without removing the pilot screws,you may have ruined the o-rings on the pilot screws.
Rick

[TDodge7]

i didn't soak them , i removed everything , cleaned it , and made sure i could squirt carb cleaner thru all the circuits (and i could)

[scalded dog]

TD7, if the carbs are clean, and synched, all of the problems I have read here, could be caused by the pic-up coils, there is several tips on this in the tech section. Later 'Dog

[Ken Talbot]

I'm putting my bet on "running on two" also. My second bet is you've got at least one broken pick-up coil wire. Ths only time I've ever experienced that sort of lack of power has been with a broken wire, or one shorted out from torrential rain.

Spritz a bit of water on the headers and see which two are cold.

[slow mo]

welcome

I'm putting my bet on "running on two" also. My second bet is you've got at least one broken pick-up coil wire. Ths only time I've ever experienced that sort of lack of power has been with a broken wire, or one shorted out from torrential rain.

Spritz a bit of water on the headers and see which two are cold.

i have to agree with ken talbot my bike ran like crap untill i had the pick up coil wire fixed its worth a look and easy to get to,, ride safe ,,slow mo!!

[TDodge7]

i'm going to go check for that pickup coil wire in a few minutes . did they use the same setup on the maxim 750's ? my friend had one and we must have cleaned those carbs 40 times and it still ran horrible , missing and popping , usually only running on 2 . tho the bike had obviously been completely submerged in muddy water at some point , so that could have had something to do with it . here's hoping that wire is my problem on this xs11 .

[TDodge7]

hmmm , ok well i just ran the bike some did an ice cube test and cylinder 1 2 and 3 were all very hot , 4 was firing sometimes because it would still melt the ice , but it didn't sizzle like the other 3 . i removed the cover over the pick up coils and tried messing with the wires , but i couldn't get anything to happen except for when i'd accidentally advance it myself messing with the wires . so what to check now ?

edit : here's something interesting , the bike won't start with any of the plugs disconnected . even tho cylinder 4 was much colder than the other three if i unplug cylinder 4 the bike won't start . i tried the same thing with the rest of the cylinders , and no matter what it would not start with one unplugged .

[DGXSER]

The bike uses what is referred to as a "wasted spark" system. This means that the paired plugs (1-4 and 2-3) both fire at the same time no matter which one is at compression stroke. So unpluging one kills both. Your trying to start on two cylinders, mine has never done it either.

You need to pull the plug out and ground it to the bike with the wire attached, then you can watch the spark.

[TDodge7]

ok , well i tried that and the spark looks great , i don't see it missing at all . i also checked a few other things . the bowl on carb 4 is full , the plug comes out dry and kinda black . it's got stock jets 42.5 pilot 110 main . i tested for ohms at the ignition unit to the pickup coils , both pickup coils were in the 685-710 ohm range and they didn't change much under full advance , i wiggled the wires around for about 5 minutes and couldn't get it to lose continuity so i don't think the wires are the problem . but when i did the ice on the exhaust test cylinder 4 was the only one that wouln't make the ice cube sizzle . so there's obviously something wrong there . i'm not sure about any of the other cylinders , they all made the ice sizzle so they're atleast working more than cylinder 4 is , but you'd think even with 3 running cylinders this thing would have more power than it does . i tried spraying carb cleaner around the carb boots while it was running to see if i was sucking air in somewhere and it had no reaction . so now i'm pretty much out of ideas .....anyone ? i suppose i could have missed something in that carb , but i don't see why it would only run half the time , carb circuits don't just clog and unclog as they feel like it and cylinder 4 is definitly firing some of the time .....

[randy]

Have you tried a fresh plug in #4? If it's fouled black, it may not fire under compression.

[tarzan]

Does it start firing on all four when you increase the rpms?Like off idle?

[TDodge7]

it seems to fire on all 4 when i rev it way up , but at idle and under load it seems to only be 3 . i'm running to the store now for a set of new plugs , it's worth a try .

[DGXSER]

At higher idle you may nto be discerning the miss. Just out of curiosity, did you remove the needle while you were cleaning the carbs? When you take it on the road does it run much better at higher RPMs like over 3000?

If you pulled the needle, look at how you put it back in, the order of the parts. The needle goes in first then the spring then the cover plate. Get those first two backwards and that one cylinder will run rich as Bill Gates in the lower RPM range DAMHIKIJK

[TDodge7]

no , i didn't remove the needles . my friend just came over and we were messing with it , seems cylinder 3 and 4 are the ones not running all the time . we put some oil in cylinder 4 and as soon as the choke went on we got smoke from the exhaust , i guess i did miss something in carb 3 and 4 . so much for not doing the triple cleaning huh ?

[TDodge7]

only one problem ...i currently have the 2 offending carbs apart ...they're spotless , all jets clear .