XS1100 won't run Issues (New Owner, Help appreciated!)

[Ccitis]

Hey All,

New here, this forum has been helpful to read! Hoping some of you experts can help me get this beast back on the road. I bought a 80 XS1100 Standard a few months ago. Not running, lots of issues, cosmetically very nice. I cannot however get the bike to run. Carbs have been cleaned, re-cleaned, and cleaned some more. Original jets (as far as I can tell) in the carbs. Carbs have been bench synced. Mix screws are 1.5 turns out to start. New Plugs. New Plug Caps. Battery is good. The advance mechanism is free, and all wires there look intact. Had to add new petcocks (non vacuum) as the previous owner had epoxied them to stop leaks, however this ruined them for a rebuild and they still leaked. Gas tank has been cleaned out and is in good shape.

The symptoms are, the bike will start on full enrichener... I notice usually one pipe stays cooler than the others, but this seems to switch to different cylinders. When I go half on the enricher, all cylinders come online. The bike does not sound like it is running well at this point, stuttering a touch and barely idling. Any throttle, or off enrichener the bike dies. What gives? The carbs should be ok, so I am leaning towards coils or electrical? Any advice is welcome!

[DiverRay]

Lets start a list.
1. check float levels, all four NEED to be the same.
2. Check coils with a VOM, primary and secondary resistance. This is between the small wires that give 12V. to the coils, and between the wires going to the plugs, with the plug caps REMOVED.
3. Check the plug cap resistance, should be about 5K Ohms between the plug connector and the coil wire connector. The caps unscrew off the wires.
4. Check the pickup coil resistance at the ICU box. One connector has 4 wires, should be about 320 Ohms if I remember correctly.
5. While checking at the ICU, move the advance plate or pull on the wires at the pickup coils. Look to see if the resistance changes. If it does, bad wires to/from pickup coils.
6. If all this checks out, report back and we'll go a little deeper.

[DEEBS11]

Ditto on what Ray said. You are by-passing the float chambers when you activate the enricheners. This seems to bring your engine on-line. It seems like you are not getting enough fuel in the float chamber. An 80 XS11 should have later floats in them (black plastic not brass). Float levels should be checked. Float pins should be checked. Float seats should be checked. Sometimes people use Chinese carbs kits and then the bike no longer runs. They give up and sell the bike with bogus parts. Watch out for that.

[Radioguylogs]

Seems your fuel mixture is lean.

How about setting the idle mixture screws out 2.5 turns instead of 1.5 turns?

[Ccitis]

Ok, I appreciate all this info. Something to work through. I set the float levels to 23mm (they are the plastic floats). They may be a TOUCH different from each other, but nothing noticeable. I used the bottom end of a digital caliper from the gasket surface (no gasket) to the top of the float.

I am pretty handy with mechanical stuff on bikes, but a total noob when it comes to electrical. I have a multimeter, but I am not entirely sure how to do what DiverRay said there. I don't know how to locate the spot on the coils or the ICU box (Not sure what that is, is it the ignition box under the seat?). Radioguylogs I will certainly try and turn them all out a touch more and see what happens.

Its funny, I bought the bike for cheap, it is cosmetically very nice, and the guy said "everything works as it should"... not so much. This is fine, as I really enjoy working on bikes in the garage and have the setup for it. Brought a 71 CL450 back from the dead a few years ago. This XS is proving to be a tad more challenging though. Again, your comments are appreciated.

[Ccitis]

Tried 2.5 out. Started on enrichener full, ran kind of on half (missing)... Would not run off enrichener, and when opening the throttle sounded like a few cylinders came online but blew a bunch of smoke out the back...(could be from not running in awhile). The plugs are noticeably fuel soaked as well. I am thinking it is not getting consistent spark. Spark plugs on the engine case show spark, but who knows what it is doing while running. Number 1 cylinder was not online until the enrichener was dialed down to half.

[cajun31]

Do your jets have the genuine Mikuni logo on them? Pictures are worth a thousand words. If you can take some pictures of your carbs. It will help us identify what you are working with and our response will be much more specific. If your jets don't have the square within a square logo then someone has been at the carbs with an aftermarket rebuild kit. It make a difference and can sometimes cause carb issues because of the inferior parts. Not saying the bike won't run but it makes things a bit more difficult. Seems that those aftermarket parts, although marked as the same sizes ... etc... are sometimes not and can cause lean or rich conditions. Sounds like you are getting spark on all cylinders so I am suspecting that your carbs are still your problem. What overall condition is the bike in? Normally we tell folks to check all grounds for corrosion / buildup and make sure you have everything cleaned at those connections as well as the fuse panel. By the way has the bike still got glass fuses or have they been upgraded to ATM fuses. If not upgraded that should be on your to do list. First things first though you need to get the bike running, the reason your here asking questions. Get those pictures posted asap. Good luck.

[Ccitis]

Do your jets have the genuine Mikuni logo on them? Pictures are worth a thousand words. If you can take some pictures of your carbs. It will help us identify what you are working with and our response will be much more specific. If your jets don't have the square within a square logo then someone has been at the carbs with an aftermarket rebuild kit. It make a difference and can sometimes cause carb issues because of the inferior parts. Not saying the bike won't run but it makes things a bit more difficult. Seems that those aftermarket parts, although marked as the same sizes ... etc... are sometimes not and can cause lean or rich conditions. Sounds like you are getting spark on all cylinders so I am suspecting that your carbs are still your problem. What overall condition is the bike in? Normally we tell folks to check all grounds for corrosion / buildup and make sure you have everything cleaned at those connections as well as the fuse panel. By the way has the bike still got glass fuses or have they been upgraded to ATM fuses. If not upgraded that should be on your to do list. First things first though you need to get the bike running, the reason your here asking questions. Get those pictures posted asap. Good luck.

Hey, I am not sure. I will check next time they are off the bike. They are on now and I am trying what I can to narrow down whats going on.

[DiverRay]

If someone put in non Mikuni jets, you WILL have problems! Ask me how I know.... I no longer change any jet, just clean them and re-use unless I do need to re-jet for mods. Also, check the float needle and seat, some of the replacement parts will not seal correctly.
Also, check to see that the float does not get hung up on the bowl gasket. Sometimes I need to cut a bit off the inside of the gasket so everything is clear. It's always a good idea to "bench test" the floats. What I do is put the carbs upside down on the bench, and put my small fuel tank about one foot above them. Turn on the fuel and make sure that nothing is leaving the closed needle/seat on the float.

[Ccitis]

I notice the float needle seat is not TIGHT in the original, however when I fit Keyster seats and needles the carbs leaked so went back to the ones that were in there. I will check the carbs again once off. I have another question, on the number 1 and number 4 carbs, I have a rubber plug on the outside of the carb on the other side of the fuel source passage. I do not have rubber plugs on any other carbs. Is this a problem?

[DEEBS11]

Ccitis, a few photos would be very helpful. Your latest writings would indicate a rich condition and leaky float valve seats would certainly do that. I think you are talking about the casting hole as indicated in the picture below. I think the rubber plug is cosmetic.

[Ccitis]

Yes, thats the plug I mean. I will pull the carbs and take some photos. Will replace the float seat o rings too.

[Ccitis]

Tried to upload photos, says the file content is not recognized? Simple jpeg, never had any issue on any other forums...

I replaced the o rings on the float seats, now they are tight and snap into place. Re-confirmed float heights. Confirmed no gasket touching float. Everything looks good on the bottom end. The jets have the Mikuni logo on them. You can see on the intake into the motor, the boots are wet (boots are new btw). I would agree this means VERY rich. Anything else to look for while the carbs are off again?

[bikerphil]

What about the pilot jets, the ones down in the towers. Are those the correct type? Many rebuild kits have the wrong type and will make it run very rich. I'll post a pic of the correct and incorrect types.

Incorrect type on left, correct type on the right...

[Ccitis]