SPLINTER wrote:Nills, the wires are maybe 4 years old. Coils appear to be OK, visually. I'm speechless. Its even worse now, after I adjusted the floats and re-sprayed and compressed air cleaned the jet on carb#1, the one on the side. Going down the road at 5000 rpm's you can't really notice it but I know its still there. Its a real disscouraging process.
If you know it's there at 5,000 rpm than that would make it less of a carb issue. Back to basics, plugs leads, coils then go from there.
Regards
Goss
Onboard http://www.youtube.com/watch?v=EqWSsdKtd64
Bike http://www.youtube.com/watch?v=ofjFhEd3
Hi Goss! yes indeed. At high speed its almost unditectable. Those of us who listen to our engins have become used to hearing the correct sound they should make. I could here the miss at all speeds, just not nearly as bad as when the bike is in idle mode. I will check all electrical this weekend and report back.
Couldn't wait till the weekend to run the testing, so last night I checked the coils and cables for leaks and found nothing. I recorded a couple of videos that I'm trying to post and see if that helps in the diagnostics. Not sure the sound is good enough. But here they are anyhow. I'm still baffled.
As soon as I figure out how to attach a video, I will. I'm trying!
Start pulling plug wires one at a time (while it's running) and see if any one wire off makes no difference in the miss. Use a heavy leather glove and make sure no gasoline is near.
That would narrow it to one cylinder, whether carb or valve or spark. Does it just do this out the left side? Also, no matter the reason, one pipe should be cooler than the others.
I'll have to review the entire thread, but did you do a compression check? A burned (or tight valve) will act that way. And these engines will burn a valve now and then.
Sounds to me like the bike might be on five cylinders, maybe even four, with one trying to kick in occasionally. It's very hard to tell from the video audio, and I could very well be wrong, but that bike just doesn't sound right at all for some reason. If it was here in the shop I'd know pretty quick. :)
Could you post another video with the bike revving up somewhat (say to 5 or 6k)?? That could help quite a bit.
Next time that happens, use your browser's back button and then select and copy the text, then either submit or start over, pasting the text you just copied. Most of the time that works, and still might work if you haven't closed that window.
N.
Nils Menten
Tucson, Arizona, USA
'82 CBX, among others.
Before I address the last couple of posts, let me tell you what I did so far. Checked the coils again visually and with a grounded wire and found no leaks (engine at idle and revved up). Got the manual out and started checking the ignition system starting with the spark plugs. Checked spark on all plugs through the Pulse generator/rotor. All plugs had a healthy spark. Checked coil resistance and all were within 530 +/- 50 Ohm. Checked connector coming from the spark units and the reading that should be 12 v was 3.08 v (odd). After grounding the blue wire as directed in the manual, the readings should be between 0-2 v had no change. Can it be that all three of my spark units are shot? I've stopped here to find out why these readings are off. Anyone want to take a stab at it? I will post another video/audio with the engine at higher RPM's and see if there is a big difference. I'd also would like to try the test Dave suggests by unplugging one spark plug wire at a time to see if the miss goes away. Sometimes I feel as though it is running on 5 and maybe even 4 cylinders. And yes Dave, its only on the left side. I cant here it at all on the right bank. As far as the pipes or pipe being cooler that the others...IMO the sporadic miss wouldn't course the pipe to be very different from the rest. I could stand corrected though. Valves...not a chance.
Nills, everything I tried to retrieve the post failed. I've learned the hard way.
Quick question: can the spark units be checked individually? I'm also tempted in buying a coil tester to check the coils a bit more.
Just to clarify - you are looking for the plug cap, that when pulled, DOES NOT make a difference in the sound. Pulling a completely healthy cylinder's plug will make the engine sound decidedly different. Again, compression checks out OK in all cylinders and valve clearances are verified normal?
Spark unit tests are kind of iffy. Unless completely fried by high voltage or the like, only one of the three units go bad at any one time. I suppose you could have a partially working one (broken wire somewhere) but it does not sound like that's your problem. I can send you a known good one to try, or all three.
