Popping anyone?

[SPLINTER]

Dave, I may take you up on the offer. Can I give you my UPS account number to ship with? Then again, your gut feeling that it's something else. I was going to say I was about to take another video with the engine at higher revs and post. But in reality, I have a problem with the incorrect voltage at the connector going to the spark unit...so there starts the process. I know Goss and others will chime in with thought provoking views.

Leslie

[Jeff Bennetts]

Are any of the connectors warm to the touch?

[SPLINTER]

Just got back from a ride so...the connectors are warm now. I'll have to check them tomorrow with just the ignition on. I see your point though. Maybe some corroded/dirty contacts? They appear to be clean but I'll recheck and clean anyways.

[Goss]

Leslie,

I would swap plugs from the left side with the right side of the engine and see if the misfire moves over. I just have a feeling that this could be as simple as that. I have a MKII Jaguar and chased an electrical problem for many hours only to find that a plug was breaking down, it had less than 1,000 miles on it!

Regards

Goss

[daves79x]

Excellent suggestion Goss. I was about to say that we need to start from the beginning - plugs being the first. I can send the 3 spark units (brand new from a school bike) on Monday if your weekend testing yields nothing new. Keep us posted.

Dave

[oilheadron]

We have LOTS of problems with the basic NGK plugs these days (just in case your bike has NGKs in it), and have had for several years. A new plug can get a little wet and it just flat DIES. If you stay with a basic-type plug I would use Autolites. They don't give us any problems at all. On the other hand, if you want a Cadillac plug, get Denso Iridiums. Yum, yum!

[SPLINTER]

Ron, I do have NGK plugs and replaced them early on to see if that would solve the problem. Can one of them be bad already? not likelly. I will try the suggestion about swaping left side with the right side and see if the problem moves over. I'm still baffled with the voltage at the spark unit connector. I'd like to find the culprit of that little problem. I'll re-read the manual again and follow the procedure closelly.

[oilheadron]

"Can one of them be bad already? not likelly."

Hell yes it could be bad, especially if they've been run in a cylinder that had problematic carburetion. I'm not exaggerating how bad these plugs are. We basically replace them day in and day out.

Ron

[SPLINTER]

Unplugged the #1 spark plug wire and engine drops rpm's very noticably. Unplugged the #2 and absolutely no change. Using a screwdriver, I can check the spark against ground and the spark appears to be healthy, yet possibly missing every so often. #3 makes rpm's drop too. All do except #2. So now we're narrowing it down. Finally! Will let the bike cool down and replace the #2 plug with #6 and see what kind of results I get. I'm getting a little excited now! May be on to something here.

[SPLINTER]

Unplugged the #2 wire and the missing appears to be gone. Not sure where to start next. Still dumbfounded as to the voltage on the connector coming from the spark unit. Question: can a coil fail only on one side? From the looks of it I now narrowed it down to the one circuit #2. As far as I can see, the coil that supplies the #2 plug, also supplies the #5 plug. If this coil fails, wouldn't it cause plug #5 to fail as well? or are they independent?
Let me re-word the statement I made earlier. When unplugging the#2 wire, there may be an ever so slight change in the rpm's, but not nearly as when any of the others are unplugged. The popping seems to be gone.That's better. I'm on my 5th post edit. Patience my cyber friends...I'll get it all down.
I did swap the #2 plug with the #6 plug and nothing changed. Failure still at #2.

[oilheadron]

Don't have time to read through the entire thread right now. Have you checked the resistance on the #2 spark plug cap? It's probably supposed to be 5k ohms, but I'd have to check a CBX service manual to be sure. Also, make sure that the cap is securely "screwed" :) on to the plug wire and that the plug wire ends aren't "green" (corrosion).

[daves79x]

Have you checked the compression in #2 cylinder? If you have spark but low compression - that's the problem. If you have spark and normal compression, then it's still the carbs - and that's still my bet.

Dave

[SPLINTER]

Ron, the plug caps are in good condition. Wire brushed them clean while assy. Boots are clean and just a couple of years old. I have the steel breided ones. I'm thinking of pulling the carbs off again. Not what I wanted to do but indications are pointing that way. No one has been able to address the question of the low voltage at the spark unit connector. I'm hoping someone will be able to shed some light on that issue. I do not have a way to check compression, yet, but will keep that in mind when and if the carbs come off again. I will be swapping the spark units today and see if the problem shifts to another cylinder.

[daves79x]

Leslie:
I'll be sending you a PM also, but I'll address what you've done so far. Swapping spark units is easy enough (I think) on your '82 and will tell you if the miss moves. Good idea.

Before you pull the carbs again, please do a couple of things. First, you really need to borrow or beg a simple compression gauge to check the health of the cylinders, comparing all others to # 2. It's easy to do and in your case absolutely necessary. Whilst you are tracking one of them down (I'll even send you mine if you want) please pull the valve cover and do a comprehensive valve clearance check. It may be as simple as a tight valve. You've not yet indicated that you've done that, so you really need to. The valve clearances tighten up over time, especially the exhaust. They never get loose. I've seen several that tightened up to the point of holding the valve open.

Then before you pull the carbs again, do the simple float bowl fuel level check with a clear plastic tube that you may have read about in AJS's thread. You can do that on the bike and it will tell you without a doubt what the float level is. Compare 1 and 2. You can do all this without taking the carbs off. It may tell you a lot.

Dave

[SPLINTER]

Dave, just got back from a couple of auto parts stores and couldn't find the right thread for the compression gage. Everyone has 18 & 14 mm but not 12. After swapping plugs nothing changed. I'll be checking some motorcycle shops come Tuesday and will buy the compression gage. Pulling the valve cover off???? That would defenitly be going in deep. Just hate to do that but will, if there are no other avenues to explore. This bike just has 40k miles on it. I've put about 7k since I had it. Dave, why am I getting the low voltage at the spark connector? (3.08 v across the top row of pins and .08 v on the bottom row) Wouldn't this be a must solve first before going any deeper? I will also swap the spark units with eachother and see if anything changes. Found a coil tester on line that I may go ahead and buy to eliminate the possibility of a bad coil. Could have had a live-in French hooker for a year with what I seem to have spent on these issues. Who knows...maybe I'll cut my looses and give her a call. lol Back to the garage for more testing.