Need serious help

[AggiesaurusRex]

I have an 1980 xs1100, it ran (laggy but fine) until I cleaned the carbs, had to rejet, and replaced the oem coils with an aftermarket set. (I know, I know, I should have tackled on thing at a time but you gotta learn somehow)(Trust me now I know)
Heres the run down as it sits now.
She won't idle and has SERIOUS backfiring.*
Only consistently runs on the right most cylinder with the left three sometime popping in and out when you give it more throttle. They are sometimes there when you first start but backfire out.
Plugs going from the left to right are: 1) is getting oil on threads, 2) getting what looks like dark oil on tip, 3) looks brand new still, 4) looks lean and a dark gray.
Since it won't idle on its own you have to maintain trottle, you can't shift without serious knocking, and honestly I didn't even try to force it given the reputation for transmission issues on these guys. I started it in first after that and only did some circles in the space behind the shop. (It's parked at work)
It is seriously ROUGH and I'm hesitant to "ride it out" in first in fear of something serious being afoot.

Some background info:
The carbs on the bike do not allow you to adjust the idle mixture screws, they are preset and metal tabbed over.
I have pods and straight pipes. (This was how it was when I bought it)
I have no fuel Octopus set up, front petcocks are connected together, rears have an inline and loop to opposite side T on carbs.
The bike sat for three months.
Oils been changed.
Everything with the exception of the idle screws and air mixture screws(?) are new. I have 110 size main and floats are at 24.5


Where do I even start? I can take a video tomorrow at work and post it so you can hear for yourself. She's mean, she's loud, and she's very angry.

[TopCatGr58]

Hey there,

Ooh boy! First, with the aftermarket coils, just need to make sure that you removed/replaced one at a time, OR marked/labelled the wires and coils so you were able to keep which coil went to which harness connector, and therefore which coil feeds which pair of cylinders. Once you have verified that the coils are correct, and you are getting fire in all 4 plugs, then you can look at the carbs.

Okay:
1) with Pods and Straight Pipes the 110 main's are probably way too lean. Would think you would want to start with 117.5 or even 120's.
2) You need to remove the caps over the pilot SCREW ports to remove the screws to ensure that you get that part of the circuit clean...easily clogged with gum/varnish from old fuel, as well as to be able to adjust/set the idle circuit better!
3) What type of jets did you get? These carbs do NOT like any aftermarket jets, GENUINE MIKUNI jets are what are needed....especially the Pilot jets....the aftermarket ones are reknown for being too big and too rich otherwise.
4) When you took the carbs apart, were there any rubber caps over the PILOT jet towers? The early 80 carbs can be the bastardized type that have a sharing tunnel between the pilot and main jet tower, and requires the rubber caps to prevent the pilot jets from getting too much fuel directly from the bowl vs. via the main jet tunnel. But if no tunnel, then you do NOT use the caps, so the pilot jets CAN feed from the bowls.
5) The 24.5 mm float height is too high....too lean. 23mm is the beginning setting.
6) You say cleaned carbs, did you actually take the main jet NEEDLE/Emulsion tubes out and ensure the side ports are clear and open?

Most folks will tell you that as long as you have STRAIGHT PIPES on there without any sort of muffler or some little bit of restriction to provide a little backpressure, that you will not be able to get it to run properly, idle smoothly and such!


T.C.

[AggiesaurusRex]

For the coils:
Orange should feed the left coil which fires into 1 and 4, and red/white feeds the right which fires 2 and 3, correct?

For the Carbs:
I've been trying not to fiddle with the idle screws but if its essential then I'll get into there.
I had jets from a kit which didn't specify Mikuni or not so I assume they were not, but I think you're right and they're also way too lean.
Where would you recommend a place to get genuine jets? I'd like to order a few steps all at once. Would you recommend 45 Pilot's, 120/122.5/125/125 Main's. (stock was 115&120/42.5) Also will I need to keep 2&3 larger like stock was or will it be alright to run them even across the board?
There were no caps on the towers. I'll reset the float height at 23 to start at. Emulsion tubes were taken out and cleaned as well.

[BA80]

Make sure ALL passages are clean, that will require removing the idle mixture screws. Pay particular attention to the idle mixture screw orifice and the 3 tiny holes in the top behind the butterfly valve.

Be sure and remove the needle jets (emulsion tubes) and be sure they and all the passages there are clean.

Put the ORIGINAL jets back in. Sync and adjust the mixture screws. (start at about 1 1/2 - 2 turns)

See how it is then.

Have you checked the pick up coil wires for breaks? Your carbs might be having an ignition problem.

http://www.xs11.com/forum/showthread.php?t=543

[bikerphil]

For the coils:
Orange should feed the left coil which fires into 1 and 4, and red/white feeds the right which fires 2 and 3, correct?

Orange is the trigger wire (-) for the left 1&4 coil, gray is the trigger wire for the right 2&3 coil. Red/wht is the (+) power wire, it splits going to both coils.

[ViperRon]

First thing is to get those little caps off the mix screws Use a small drill bit and gently drill through the caps they are lee than 1/8th inch. I say gently because if you force the bit it will go threw an hit the head of the adjustment and mess it up. I drilled a 1/16 hole and ran a little self threading screw in and then yanked and they popped right out. Like TC said pull the carbs off put original jets in search here for how to do a bench sync on carbs make sure your floats are mechanically set right and make sure all passages are cleared. You can usually bench set up these carbs and the bike will Idle a little high at about 1500 and respond correctly to throttle. There are several write ups on how to adjust carbs. If you are sure the floats are right passages are clear and you have the basic number of turns on Idle mixture it should run and idle. If it will not Idle and run and you are sure carbs are back together right and no vacuum leaks then you have electrical issues There are several write ups on step by step checking from the pickups to the coils to the plugs. You will need an ohm meter and a DC voltage meter and you should be able to test step by step threw it. There are two identical systems that run 2 cylinders each and you can do some swapping around to identify most issues you just have to get the write ups study what you are doing and you can isolate issues. Once the carb are clean and no electrical you can do the basic set up and sync by checking rpms to get it running.

[MaximPhil]

Orange is the trigger wire (-) for the left 1&4 coil, gray is the trigger wire for the right 2&3 coil. Red/wht is the (+) power wire, it splits going to both coils.

More "Serious Help" from bikerphil A true Guru.
Maxim Phil

[skids]

[QUOTE=ViperRon;486337]First thing is to get those little caps off the mix screws Use a small drill bit and gently drill through the caps they are lee than 1/8th inch.(snip)QUOTE]


Be careful with the rocking back and forth of the caps. It is easy to break the "pipe walls" that they are seated in.

[Bikes]

Coils resistance? Ballast bypassed? Or not...

[AggiesaurusRex]

Sorry for the late update, everything is wired correctly and after another go around in the carbs it now runs and all four cylinders fire. It appears it was just waay to lean.
However white smoke comes from the front of cylinder 2 and out the rear of both pipes. Its a pretty good amount. It appears like a weld on the head of the exhaust was very poorly done and has some holes. In addition to the smoke there's a good and plenty oil on the plugs. Compression test revealed 135/120/115/130

[DiverRay]

If the engine sat for a while, it may need about 500 miles of riding to get the compression back up. The oil may also be from valve seals, so that also may wait until it's running well.
First fix is the exhaust leak! If it's THAT bad, you MIGHT burn a valve because of it! Once the weld is fixed, check #2 carb, and the vacuum line down to the advance. A quick, but possible dirty check is to disconnect the line off the #2 carb body, and with the left cover off suck on the line while watching the advance mechanism. You should be able to move it. and if you put your tongue over the end of the pipe, it should NOT move back. If you have a hand vacuum pump, it's much easier and cleaner. Just pump to about 15", and watch that it does NOT drop over 30 seconds. IF it does, then you probably have a bad advance unit.
IF you have fresh oil in it, add about 1/2 pint of SeaFoam or Berryman's B12 Chemtool in the oil, and WITH A FAN BLOWING OVER THE ENGINE run it for about 15 minutes,DO NOT RIDE IT!! shut it down, let it cool a bit then change the oil. This will clean out a LOT of gunk in the engine, and help loosen up the rubber in the seals.