Spark plug wire zapped me

So just as the title says, I'm having an issue with my #4 spark plug wire. It seems to only work when it wants to. The bike wont stay running unless I leave the choke on or hold the throttle. I was checking the cables for looseness and as I held down the #4 wire I reached over to adjust the choke. That's when I got buzzed.

When I start the bike up the #4 cylinder stays cold until I start riding it then it starts firing. So my question is, what can I do to get a good ground on the cable without actually having to replace the coil?

Any help would be greatly appreciated.

 

I would say you have a problem with the #4 plug wire since it bit you. Your description tells me you have bigger problems with the carbs. I think its time to pull them out and do a through cleaning. There are plugged idle passages in the #4 carb.
The plug wire can be replaced but think about looking into the carbs also.

 

What would the carbs have to do with the spark plug wire not being grounded? I know the problem is the cable. My question was is there a way to fix the cable without replacing the coil. A bad connection tells me there is a weak spark which is keeping the cylinder from firing at low RPMs.

 

The plug wires on these old bikes are not very good and now being 30 years old they need replacement. I'm all for a set of Dyna coils upgrade when a member can afford to do so.

But.......I'm thinking along the same lines as mlew. Think your carbs may need a double check on the idle circuits.

MN

 

I'm trying to take care of one thing at a time here. If there is no way to fix the cable then I'll replace the coil. Once I have good spark in all 4 cylinders I'll move on to carbs if I'm still having issues with it idling. With it only running on 3 cylinders right now there's really no sense in making any adjustments to the carbs.

 

The spark plug caps on these bikes are the "screw on" type.
Pull the plug cap off (unscrew it).
Have a look where the wire goes & you will see a pointy "prong" with a screwed thread on it.
Make sure it's clean & free of any crusty build up.
Trim the #4 spark plug wire (1/8"-1/4") & screw the cap back on.
You might even want to do this to the rest of them as well.

Good luck.

Tim

 

The bad wire can be replaced without replacing the coil assembly. There are two options.
1- Our parts supplier Chacal has a kit to splice a new wire onto the old coil.
2- Cut the coil and install a new wire.
Here are some examples
http://www.xs11.com/forum/showthread.php?t=137
XJ coils are similar but not the same.

 

Thank you, Tim. That's definitely a good place to start. Sounds easy enough to do and if that takes care of the problem (even if it is just temporary until I get a new coil) I can at least move on to the carbs if I'm still having the idling issue.

 

Thank you, mlew. If trimming the wires back a bit to get a better connection doesn't fix the problem then replacing the wire as you suggested will be the next step.

Unfortunately it is almost 11 pm here and raining so I wont be doing anything with the bike tonight. At least I have something to look forward to when I get off work tomorrow.

 

So I got home from work today and trimmed the wires back. Still having the same issue. I wanted to check the voltage coming out of the plug wires with the bike running. Since the #4 is the one I'm having problems with I disconnected it from the plug. When I did that a big blue spark jumped from the end of the cable (where it attaches to the plug connector) to the valve cover. Is that normal or should I just go ahead and replace the coil?

 

If it jumped that much there is nothing wrong with the coil or wire. Since the arc was blue and jumped that gap it means everything is good. I still think you ar ehaving problems with #4 carb.

 

Sounds like the coil is working fine if you are getting a nice blue spark from the wire.
It could be a crack in the plug cap.
Swap #4 cap with another cap & see if the problem moves with the cap.
If so, just replace the cap.


Cheers.

 

I guess I'll have to replace the cap and move on to the carbs. Is there a way to safely check the voltage output of the wire? I just want to make sure before I go ripping the carbs off yet again. I just had them off this weekend and stripped them down for a cleaning.

At first I thought the rough idle was a fuel problem, but once I was zapped I figured it had to be the plug wire since that was the only cylinder not firing and the only cable that didn't have a good ground.

 

There is no way to safley measure the output voltage of a ignition coil. The best way to test it is by seeing how much gap the spark can jump. If your coil can jump a 1/2 " gap with a blue or blue/white spark them it is OK. As the coil weakens the spark color will turn orange.

 

Well from the spark I saw earlier I'd say the coil works just fine. Maybe after I replace the caps the issue with it shocking me will be fixed.

Now assuming I am getting a good spark to the plug: What should I be looking for when I tear the carbs apart again? Not really sure what's keeping the bike from idling.

 

Things to look for in the carbs;
Idle jets- remove them clean and make sure they are not clogged
main jets and emulsion tube- remove and clean
Remove idle mixture screw , spring washer and o-ring
blow passages and jets with carb cleaner and compressed air
Float levels are critical, set them right
Replace all gaskets and o-rings if they are showing signs of cracking
Carb slides should move freely in the bore
Bench sync
running sync
Don't forget to check valve adjustments

 

drtysnchz If the shock you got came directly from the plug wire change it. Because it will be grounding out against the frame or any other it touches and is BAD. So first change that wire. THEN look into the carb issues because if the wire grounding out messing with the carbs wont fix anything.

 

The idle circuit in that carb is most likely plugged with crud. You will need heavy nylon bristles from a brush to push into the passages and blow lots of carb cleaner through. Finish off with compressed air. Check you float levels wet and bench sync before re-installing.

 

Today I fiddled with the wire once more. I made sure the caps were on tight and started the bike up. As I held the spark plug wire I was touching different parts of the bike to see if I could duplicate the shock from a few days ago. It didn't happen. I figured I finally had a good connection to the plug. This, however, did not make the bike idle any better. So to rule out any other electrical issues I swapped plugs between the 1 and 4 cyl. Then I hooked the #1 cable to the #4 cyl and vise versa. The #1 cyl was firing with the #4 wire yet the #4 cyl stayed cold.

I reluctantly moved on to the carbs :?
Completely tore them down minus actually separating them from each other. I really didn't want to go through them again so I made sure to blow out all the passages with carb cleaner until I had good flow on the other end. Feeling satisfied with my cleaning job I reassembled them, put them back on the bike, threw the tank on and started her up. Not a damn thing changed.

Considering how short the summers are up here I'm considering riding the bike just the way it is until the season is over. The bike runs fine and I can just deal with keeping my hand on the throttle every time I stop. I really don't know where to go from here to fix the idling problem.

 

I must have been typing while your message came in, MN. Didn't mean to ignore your suggestion in that last post. I cleaned as much as I could with a needle and carb cleaner. What exactly is the idle circuit so I can focus on that when I pull the carbs back off tomorrow. I gotta say I'm getting pretty good at removing and installing those carbs haha

 

Would you be willing to try a few more things before giving up?

If so then let's check a few more things

Compression PSI________
Float level clear tube should be even with washer on float bowl.
Vacuum cap removed and plastic tube connected , pinched off with opposite end in small container of fuel. Let a little fuel into the vacuum port and see if that cylinder fires.
Lastly your sync could be off and causing this problem. Was this bike synced any time in the resent past?

 

I wasn't planning on giving up. Just didn't want to lose anymore riding time lol.

I have not checked the compression yet. I'll see if I can get a hold of a tester tomorrow.
In order to tackle the float bowl level I'll have to extract the drain screw since it's just my luck that the only stripped screw on the whole bike is the one on the #4 float bowl.
Now the only time time this cylinder doesn't fire is when the bike is under 2500 RPM. I would have to leave the choke on in order to keep the bike running.
I synced the carbs myself while I had them out earlier.
I'm willing to do whatever it takes to get the bike running right, but if anything is going to leave my bike out of commission for a while then I'd rather wait until winter time.

 

Did a compression check today.

#1=160
#2=130
#3=155
#4=155

Compression was checked with all spark plugs out and throttle full open

 

I took the carbs out once again to clean them and blow air through them. I removed the mixture screws and noticed the #4 carb was missing the washer and the o-ring. I also noticed that the float bowl is missing the brass piece that mates against the brass tube. I'm pretty sure installing these parts will take care of the idling issue, or at least I hope so.

 

my bike would not idle either, but was running fine with ANY throttle at all, or with the "choke" lever on. i cleaned the carbs with barely any avail. i bought a carb sync tool (motionpro) on ebay, and synced the carbs. this made a HUGE difference and now the bike would idle without any assistance. i then messed with the idle mixtures to get it perfect ( the engine will spin faster when the mixture is good). i tried a gunson colortune but found out that it seemed just as accurate to tune the idle mix by ear. and just as easy, if not more simple, too.

id say the carb sync is what made the biggest difference, and the adjusting idle mix "perfected" it. i have relatively poor compression but after the sync and tune (which was way easier and less time consuming then expected), it runs great!

good luck with your idling issue!

 

Ok your compression looks good, fairly even except for #2 ,The cylinder has spark and compression the only thing is missing is fuel.
Remove the pilot jet, blow carb cleaner in there and see if any comes out the holes just behind the throttle blade. You can kind of see where the fuel is supposed to go. Work on that and see if you can increase the amount of fuel that can move through that passage.
As far as the float bowl goes just swap it with #3 carb. We need to know the fuel level in that carb. Hang in there we are getting close

MN

 

There's two things I don't like in his write-up==

1. the compression on cyl two is 130 while the others are 155/160

2. " I removed the mixture screws and noticed the #4 carb was missing the washer and the o-ring. I also noticed that the float bowl is missing the brass piece that mates against the brass tube."

That last quote has enough stuff in it to cause all kinds of problems.....
Fix those, and things should get better quick, too.

Dave F