Popping One Cylinder

[2004LEBanshee]

Why does my banshee pop or crackle out of one cylinder. It has 340 in it and was jetted fine. I Just started it up to warm up and one cylinder is crackling. I ran it up and down the street and it runs great and no backfire. So I changed plugs and they are pretty dark and wet. Also the exhaust tips have some oil on them. Is it maybe running to rich or may be the carb is a little clogged.

 

I need help soon because I am leaving to go ride in a half an hour. Any info appreciated.

[Big Blue]

maybe a little rich i had 320's in my shee with the same mods except t6's.

[scotts96fast]

if she crackles it's rich for some reason and I don't think a carb is clogged.if you didn't do ANYTHING to your machine and this problem happened,maybe you have a bad spark on one side.(stator perhaps).

 

When you say "it pops" is it more of a backfire?

[mrmatt]

Are you saying that it only 'pop or crackle out of one cylinder' when it is idling, and that it ran fine down the road? If so, then the idle adjustment could be different on your carbs or they could be out of sync.

[2004LEBanshee]

First of last week i changed the needle to the wrong direction then I put it back befor a rideing trip and it ran good. At the end of the trip it started this. Now it is still doing it.

Basicly It is like a lite pop or crackle. There is no Back fire when reved or drove with. If I rev the engine it does pick up but when i hammer it, it dosent make a big backfire. I rode about 2 hours today and it kept doing it but ran otherwise awsome. I looked at the plugs and it is brown colored also. So you guys are saying that i should try to adjust the tors nobs? I played with the tors and the air screws on that carb but it didn't go away and I've tried three diffeerent plugs. Same result.

[MotulMonsta]

What cylinder? If it's the right, your crank seal might be worn causing oil from the tranny to enter which would make it run rich. Are you running the stock exhaust? The baffles might be clogged a bit. It also sounds like an air leak in the exhaust. Do you have all your hangers and springs installed? Does your pipe seal around the exhaust port on the cylinder? Do your clamps on the pipes hold it tight? It's not electrical seeing as it happens in one piston...unless you have a bad sparkplug cap/wire. Both plugs fire at the same time. simple ignition system.

[SDD]

You would have to explain what you mean by popping. If it's more of a thud inside the motor it could be detonation from the advanced timing and high compression from the milled head. At idle does one cylinder seem like it's not firing (no smoke and cold air coming out of the silencer)? Your air screws could also be off causing a lean condition on one side. We need more info...

[2004LEBanshee]

It is more of a crackeling sound when I rev it. The sound is coming out of the left exhaust tip. My comp is 140 in both cylinders and there is no metal fragments on the spark plug and I have ran numerous tanks of gas through it so I dont think it is detonating. They both apear to be releaseing the same amount of smoke.

 

Also noticed after messing with the needle that some times when I come to a stop while ridding is has a slightly higher idle then I blip the throttle then it comes back down.

 

My exahust is fatty's power core II. Like it says

[MotulMonsta]

Carb sync could be out. Maybe you blew some packing material out of the pipe or sprayed water in it when you washed. Perhaps it's saturated.

When you mess with the needle in one cylinder it's going to affect the whole motor. Both carbs should be set EXACTLY alike. It pops at idle, that normal Maybe your gaps are off on the plugs.

If everything works fine, I wouldn't worry too much about it.

[2004LEBanshee]

I do use a pressure washer and dont plug the pipe ends like I probably should. Your saying that can cause this.

[MotulMonsta]

Yeah, the water will soak up in the fiberglass and rot it out. With constant wetting then drying and high heat, your packing in the silencers might be fried.

[2004LEBanshee]

So this would explain why after a few hours of riding on a really muddy day it started this. Or could it only be immediatly after I wash it. Also along with the possiblity of outa sink carbs.

[MotulMonsta]

well, shit happens. To me, it sounds more like an exhaust problem like a leak or blown out packing. If the carbs are out of syn, you'll get hesitation, rough idle and if it's bad enough one cylinder will run stronger then the other at idle. Also if you got dirt in the jets, you'll have poor performance from the affected side. A clogged up jet is very noticable. But you said the bike runs great other then crackling and popping that comes from the left side more so then the right. It idles fine, runs fine and both plugs read the same. It's an exhaust issue then. I bet money on the packing..or a loose connection between the silencer and the exhaust tube.

[2004LEBanshee]

Ok, I went to the store bought some packing. I changed it and now the popping is gone. Thanks alot guys especially MotulMonsta. The only down fall is it is quieter now. But thats way better then popping.

 

Thanks again.