Carb problem?

I found out recently that my #1 cylinder is not running at all. The exhaust on #1 does not get hot and when I pulled the plug, there was oily gunk all over the top of the piston. I had just cleaned all the carbs, and blew out the passages with my air compressor. No help, so I needed to replace the plug wires anyhow, so did that. Again no help so verified I was getting spark and it was good. Checked for vaccume leaks with some carb cleaner and did get a RPM jump on #'s 2,3, and 4, but no change on #1. So I know I need new intake boots but dont think that this is causing my problem with #1. Anyone know of what I can check next? It seems like the carb right? Oh yea, I checked the compression on #1 and its 130, so no problem there.

I just had a thought and went ouside to check. I pulled the boot off the intake side of the carb, and started the bike. Thought I would ckeck and see if I was getting airflow through the carb. I let the idle settle a bit so I could turn the choke down, and then blocked off the intake to that carb only with my hand, not completely, just hindered the flow a little. As soon as I did, the RPM's shot to 5000. Doesnt that mean that #1 started firing? And if so, what does that tell me?

You have checked compression and it is OK. You say there is good spark. How did you determine if there was good spark? I suggest you first eliminate ignition/electrical issues before jumping to the carburetors. The easiest way to do this is to troubleshoot by switching the #1 and #4 plug wires. See if the problem moves to the #4 cylinder. If it doesn't move, put the wires back to where they were and swap the #1 and #4 spark plugs. Sometimes plugs can have the conductor break internally and just won't fire. Once you get this done, report your findings.

I know its not the plugs themselves because they were replaced. I pulled #1 plug out and grounded it against the head and had my wife turn it over while i watched the spark jump the gap. Now you are saying I can swap #1 and #4? Do they spark at the same time? If you just mean change the wires, they are new and the problem did not change.

Travis, You asked for help trying to fix the problem. It has been my experience that if you troubleshoot things in a systematic manner and not make assumptions, you will find the problem. If you do it nilly-willy and make assumptions, the problem will become unsolvable and a major frustration. NEW SPARK PLUGS can be defective. What I was suggesting was that you first take the #1 spark plug wire and place it on the #4 spark plug and vise versa. Yes, they spark together. They may be new but since you didn't know they spark together there is a very small chance the plug wires are defective or not installed in the coils correctly. Once you have checked to see if the problem moves, if it doesn't swap the spark plugs. This pretty much eliminates most electrical issues. This is the way to troubleshoot your issue. If you would prefer to do it another way, I will let you have at it. There are various ways to learn and perhaps my exeperiences may not be the best way for YOU to learn how to fix things.

No problem, I apreciate the help. I was just saying that with new plugs and wires the problem did not change. I will however to eliminate all possibility of anything else and do what you suggested. I definataly would rather be sure of the problem and not make assumptions as you suggest. When I get home from work, I will swap #1 and #4, if no change then the plugs. I will report back my findings this evening. Thanks.

Wiredgeorge, I am so glad I took your advice. I swaped wires 1 and 4 at the coil and fired it up. And guess what, now pipe 1 is hot and 4 is not. So I guess I have a bad coil right? I did measure the secondary resistance on this one and it was the same as the 2,3 coil. 23K if I remeber right. I guess it must be shorting out under load? I will try and hunt down a coil ASAP unless you think otherwise. Thanks again for your help.

Ok here is where I am at now. The new coil did not help. I suspect #1 was firing because I had pulled the intake boot off #1 carb while checking things out. I did the coil mod and it did make a huge difference in the way the bike runs. It has never idled so well, even though it is still on 3 cylinders. Went ahead and swapped the plug wires again, no help, then swapped the plugs in #1 and #4, still no fire on #1. So to recap, new plugs, plug wires, carbs thouroughly cleaned, coil mod, balanced the carbs, and no fire on #1. And if I pull the intake boot off #1 and restrict airflow with my hand, #1 starts to fire. Tested this while holding my hand over the intake, then put some water on #1 exhaust and it was gettig hot. So I am back to thinking I have a carb problem. I also did check for gas at the carb by opening the bowl drain, and gas came pouring out. Any suggestions?

del

Your problem followed the swap. Since the plug wires that were swapped were coming off the same coil, the problem lies with the plugs, plug wires or plug cap. Try and do one step at a time as nilly-willy testing just confuses the issue (actually confuses me hehe).

At this point, since you have new plugs, wires and caps, I would begin to suspect the installation of the plug wire in the coil. Take your 1/4 coil off and pull the plug wires out of the coil and swap them by reinstalling them in the opposite hole in the coil.

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I started another thread on this because this one was getting confusing. But to close this one out, I figured out I have a problem with the idle circuit in the carb. It starts fireing when RPMs are raised, I probably should have checked this earlier, but at least all the stuff I did do had positive results.