1978 xs1100 wont start and pops thrug carb

[jorge lobo]

1978 xs 1100 wont start
rebuild carbs with new kits recomende for the model
set the timing, have red spark in all sparkplugs
it will turn and pop thr carbs please ani one can help or have any idea what is wrong

[cywelchjr]

Red spark don't sound good, it should be yellow or so. And for the popping out the carbs, that sounds like the spark being 180 out. Quick check for that is to take the swap the plug wires between 1-2 and 3-4 (it's easy to get them backwards) or swap the primary coil wires (that does the same thing.). Also, make sure that the coils are connected with 2 and 3 on one coil and 1 and 4 on the other.

[SFerinTEXAS]

Has it ever run since you have had it? Has anyone had the timing chain adjuster off the engine lately?

[FJ111200]

1978 xs 1100 wont start
rebuild carbs with new kits recomende for the model
set the timing, have red spark in all sparkplugs
it will turn and pop thr carbs please ani one can help or have any idea what is wrong

I notice that you posted this problem up on the UK site, well here's a run through of how to set up the carbs basically. There is a thread on here called the paper-clip or bread -tie method, anyway it's all basically the same.
Thanks to Miti-Babe from UK site for this.


You'll NEVER get those carbs 100% perfectly set up and that's a very important thing to remember... Striving for perfection when setting up knackered old carbs is one step further down the path of insanity than checking for hairs on the palms of your hands...

You didn't look did you..???

Good...

So... Take a simple paperclip... Straighten it out so you have an even simpler piece of wire... It's about 1mm thick, but that's not important... Your paper clip/wire is about to be promoted... It's now a "gauge.."

Now... Working from the engine side of the carbs, try to slide your gauge between the bottom of #3 carb venturi (the hole through the middle of the carb) and the lowest part of #3 throttle butterfy...

Won't fit..?? Turn the tickover screw clockwise until it will fit...

Too loose..??

Turn the tickover screw anti-clockwise until the gauge just passes through the gap...

A tiny amount of friction is what you're looking for...

You have now "set" #3 carb throttle butterfly to a "baseline" of 1 paperclip...

Congratulations.!!

Now move the gauge to #4 carb...

Gap WAY too wide..? Turn the balance screw between #3 and #4 carbs anti-clockwise until the guage is the same sliding fit as in #3 carb...

Gap WAY too tight..? Turn the balance screw between #3 and #4 carbs clockwise until the guage is the same sliding fit as in #3 carb...

You have now "balanced" #4 carb to #3 carb... Good eh..?

Now repeat the same process on #2 carb, adjusting the throttle butterfly gap with the screw between #2 and #3 carbs...

Then complete the process by adjusting #1 carb by turning the screw between #1 and #2 carbs...

You should now have 4 carbs, each with a butterfy opening of 1 paperclip....

Try adjusting the tickover screw in/out...

A 4 butterflies should open/close synchronously and by the same amount... Readjust #3 to the 1 paperclip setting and all the others "should" (near as dammit) be 1 paperclip too...


Miti

[jorge lobo]

Well I didi check the plugs wires they're god
And yes the bike was tuning and no one touch the
Timing belt.
What does it mean the red spark is that bad?
I will also set the btrfly as Miti recommended
I just realize that when I se t the timing I set the gap btwing the magnet to 0.07 and I think it was suppose to be 0.7 mm I will check this and try if it doesn't work I will follow all recommendations
What does the red spark means

[natemoen]

Well I didi check the plugs wires they're god
And yes the bike was tuning and no one touch the
Timing belt.
What does it mean the red spark is that bad?
I will also set the btrfly as Miti recommended
I just realize that when I se t the timing I set the gap btwing the magnet to 0.07 and I think it was suppose to be 0.7 mm I will check this and try if it doesn't work I will follow all recommendations
What does the red spark means

the red spark is just a really weak spark. Also having the gap at the pickup coils small will not hurt, it just can't be larger than what is in the book. Another thing to look at, if you had any of the parts of the timing/advance setup apart, the little rotor that signal the pickups has to be set in on a small peg. The peg can fall out and then that rotor will not be into the right spot and cant signal the spark at the correct time.

[brcree]

Popping

Hay Jo......after you do the steps fj111 has described I highly suggest a carb sync. when you have the carbs back on! It will make all the difference in the world! Get ahold of some sync. gauges and follow the book.

[jorge lobo]

Ok guys I did check the sparkplugs,wires and they are in the right place , set the timing magnets to 0.7 spark looks much better I did follow the paper clip advice and that is done to.
BUT IT DOESN'T START I'M ABOUT TO RESING any other ideas I don't think is the CDI box
Oh... What do you mean having the ignition 180• of
The sprkplugs still to wet what is the best way to regulate the floaters

[cywelchjr]

Ok guys I did check the sparkplugs,wires and they are in the right place , set the timing magnets to 0.7 spark looks much better I did follow the paper clip advice and that is done to.
BUT IT DOESN'T START I'M ABOUT TO RESING any other ideas I don't think is the CDI box
Oh... What do you mean having the ignition 180• of
The sprkplugs still to wet what is the best way to regulate the floaters

If they are hooked up right as far as the pairing, they can STILL be reversed as to which coil is hooked to 1 and 4 and 2 and 3, I know cause I did that. A quick way to find out if that's the case is to swap the primary wires, and if that's the case it is likely to start right up (I know cause I did exactly that), and if they are hooked backwards, your symptoms are exactly what will happen. I fought with mine for a week, and it was suggested the swap the primary wires. I did and it fired on the first try. That said, if things are working right, the spark should be fat and blueish white or yellowish white at least. However it sounds like your getting enough spark to ignite gas fumes base on the popping out the carbs, but if the valves are in time then the coils are probably electrically reversed.

[DGXSER]

As Cy stated, the timing on these bikes is pretty simplistic with the "wasted spark" system. Meaning, each time the rotor button down at the pick-up coils hits one of those pick-up coils, it signals the TCI, the TCI then fires one of the two coils, that coil sends a spark to BOTH of the plugs, one fires the fuel, the other spark is wasted.

So, you essentially have a two cylinder engine from a spark standpoint. Now it is not uncommon for folks to put the pick-up coils on the wrong locations, and hook the wires up matching colors up and then the spark is off that 180 deg. So, if you remove the tank and look at the wires that connect to the coils, one has an orange wire and the other a grey. The connectors are identical, so you can simply swap them so the orange wire goes to the coil with a grey wire and vice-versa. This will correct the mix-up of the pick-up coils, one case where two wrongs make a right.

If that does not work, and your plugs are wet with fuel, then I'd say you might need to look at your carbs. Try pulling the plugs out and let the bike sit for a few hours to dry everything out. Clean the plugs. Then put them back in and try to start it. But only let it turn over a few times, like 10-15 seconds. And see what your plugs look like then. If they are wet with fuel, then you seem to be flooding the cylinders out.

[skids]

I hate to admit it, but I did the pickup coil fix once and mixed up the positive splices. I had to reverse the connections to the spark plug coils to compensate.

[jorge lobo]

ok i did try all of the recomendet :
-carbs were flooding noow they are good
-spark is yellow almost withe
-good battery
-check the coils and good
BUT STILL DONT F..... WORKS
If the pick up coil magnets are but do i still get spark?????
any one in the area of Northern VA ?? i need help
I can afford to take it to the shop may not be worthed....

[tarzan]

Did you replace the plugs? For some reason, once they foul, I haven't had much luck getting them to work again on any of my XS's. And they will backfire,almost start,and drive you nuts. My money is on plugs. It's pretty cheap to check.

[cywelchjr]

ok i did try all of the recomendet :
-carbs were flooding noow they are good
-spark is yellow almost withe
-good battery
-check the coils and good
BUT STILL DONT F..... WORKS
If the pick up coil magnets are but do i still get spark?????
any one in the area of Northern VA ?? i need help
I can afford to take it to the shop may not be worthed....

Ok, did you swap the wires in the primary side of the coils as a test? I haven't seen anything saying you did that, and that IS one of the things that can cause the symptoms you are having. If you have done this, then the next thing would be to put new plugs in.

[jorge lobo]

yes i did swap the wires
didnt change the plugs it doesnt matter if they are brand new?
the espark is really good in the plugs i got already