Yesterday, a neighbor was having trouble getting his small push mower
started. I went to help and the first thing I did was hold the spark
plug wire out away fromt the plug while he cranked it. It started
immediately. Strangely, when I put the wire back on the plug the engine
would quit firing and begin to die. But I could hold the wire as far as
3/4 inch from the plug and the engine would run just fine. I could see
no spark at all but the sun was shinning, which probably explains that.
I pulled the plug out and the electrod in the middle was pretty much
burned up. I replaced it and it ran fine. But I have no clue why the
engine, with the old plug, would only run when the wire was held out
away from the plug.
Any ideas?
Robert Waters
[Non-text portions of this message have been removed]
need crankshaft 28t primary gear for klr600 clutch basket
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nklr spark plug puzzles shade tree mechanic
Hi Robert,
When the ignition system supplies voltage to the plug, if you could look at the voltage versus time on an oscilloscope, you'd see that the voltage rises at a fairly steep rate, but not quite a vertical line. The defective plug, when the wire was attached, had deposits which would bleed the voltage down as it tried to rise. Thus the voltage would not get to the value it would take to jump the spark gap inside the cylinder. Although this gap was much less than the 3/4 inch you saw, the fact that the cylinder pressure is much higher than atmospheric pressure meant that it took a lot of voltage to jump the gap inside the cylinder. If you had re-gapped the plug to the recommended value, the voltage requirement to jump the gap would have been reduced and perhaps the engine would have run.
When you pulled the spark plug wire loose and held it away from the plug, the voltage would not bleed off. It could keep rising to a value that would jump the 3/4" gap you saw. At that voltage value, it would also jump the gap at the spark plug electrode, causing the engine to run.
Years ago, Champion made spark plugs with a gap up inside the ceramic insulator. They called this a "booster gap". These spark plugs were more resistant to fouling. I used them in my two-stroke Yamaha back then.
I hope this makes sense.
Mike Martin,
Louisville, KY
________________________________
From: Robert Waters
To: DSN_KLR650@yahoogroups.com
Sent: Monday, August 3, 2009 3:50:30 PM
Subject: [DSN_KLR650] NKLR spark plug puzzles shade tree mechanic
Yesterday, a neighbor was having trouble getting his small push mower
started. I went to help and the first thing I did was hold the spark
plug wire out away fromt the plug while he cranked it. It started
immediately. Strangely, when I put the wire back on the plug the engine
would quit firing and begin to die. But I could hold the wire as far as
3/4 inch from the plug and the engine would run just fine. I could see
no spark at all but the sun was shinning, which probably explains that.
I pulled the plug out and the electrod in the middle was pretty much
burned up. I replaced it and it ran fine. But I have no clue why the
engine, with the old plug, would only run when the wire was held out
away from the plug.
Any ideas?
Robert Waters
[Non-text portions of this message have been removed]
[Non-text portions of this message have been removed]
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- Joined: Thu Apr 06, 2000 10:08 am
need crankshaft 28t primary gear for klr600 clutch basket
Name calling on this list is not allowed. Please follow the list's rules.
http://autos.groups.yahoo.com/group/DSN_KLR650/
Fred
List Admin.
----- Original Message ----- From: Mechanician To: DSN_KLR650@yahoogroups.com Sent: Monday, August 03, 2009 7:51 PM Subject: [DSN_KLR650] Re: Need Crankshaft 28T Primary Gear for KLR600 Clutch Basket Say Y'all, I got quite a few responses & offers & want to express my appreciation to the group for helping out. I've got a very reasonably priced inner clutch hub on the way, which will allow me to rebuild the right side with the same parts it was made with in 2006. I also have an old school 28T spur gear on the way if I ever need to utilize the KLR600 clutch basket. I'm still searching for a left side crankshaft bearing race. If anyone has cased their engine on a jump or otherwise distorted or trashed their case and can part with the bearing race, I need it. The following portion of the message is NKLR. It is addressed to any & all of those out there who's primary form of communication is accomplished with two thumbs. Your parents have failed you. I'm surprised you have pulled your thumb out of your bum long enough to stop sucking it, let alone text people with your tweets... you dumb little twit. You know who you are, well, maybe. For the rest of you like me, who understand how to form words and have probably on several occasions throughout your life stopped to render aide or assistance to complete strangers without expecting compensation or thanks but appreciated the gesture... this post of sincere appreciation is for you. You know who you are. Mechanician [Non-text portions of this message have been removed] [Non-text portions of this message have been removed]
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nklr spark plug puzzles shade tree mechanic
On Mon, 3 Aug 2009 14:02:08 -0700 (PDT) Michael Martin
writes:
SNIP> Hi Robert,
SNIP> When you pulled the spark plug wire loose and held it away from the > plug, the voltage would not bleed off. It could keep rising to a > value that would jump the 3/4" gap you saw. At that voltage value, > it would also jump the gap at the spark plug electrode, causing the > engine to run.
<><><><><><><><><><> <><><><><><><><><><> Mike, Nice explanation. Thanks for taking the time to write that out. Best, Jeff Saline ABC # 4412 South Dakota Airmarshal Airheads Beemer Club www.airheads.org The Beautiful Black Hills of South Dakota 75 R90/6, 03 KLR650, 79 R100RT . ____________________________________________________________ Too many bills? Click here to simplify your life and lower your debt. http://thirdpartyoffers.juno.com/TGL2141/fc/BLSrjpTIlMlUqOWk8rzLICFziujD9JVUvV0HJroevXdi17DgiJ61kQM9PzS/> I hope this makes sense. > > Mike Martin, > Louisville, KY
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nklr spark plug puzzles shade tree mechanic
WOW! what a great answer! Me thinks you nailed it. Thanks for taking the time. R U a science teacher?
rw
Posted by: "Michael Martin" mmartin36@... mmartin36
Mon Aug 3, 2009 2:02 pm (PDT)
Hi Robert,
When the ignition system supplies voltage to the plug, if you could look at the voltage versus time on an oscilloscope, you'd see that the voltage rises at a fairly steep rate, but not quite a vertical line. The defective plug, when the wire was attached, had deposits which would bleed the voltage down as it tried to rise. Thus the voltage would not get to the value it would take to jump the spark gap inside the cylinder. Although this gap was much less than the 3/4 inch you saw, the fact that the cylinder pressure is much higher than atmospheric pressure meant that it took a lot of voltage to jump the gap inside the cylinder. If you had re-gapped the plug to the recommended value, the voltage requirement to jump the gap would have been reduced and perhaps the engine would have run.
When you pulled the spark plug wire loose and held it away from the plug, the voltage would not bleed off. It could keep rising to a value that would jump the 3/4" gap you saw. At that voltage value, it would also jump the gap at the spark plug electrode, causing the engine to run.
Years ago, Champion made spark plugs with a gap up inside the ceramic insulator. They called this a "booster gap". These spark plugs were more resistant to fouling. I used them in my two-stroke Yamaha back then.
I hope this makes sense.
Mike Martin,
Louisville, KY
____________ _________ _________ __
From: Robert Waters
To: DSN_KLR650@yahoogro ups.com
Sent: Monday, August 3, 2009 3:50:30 PM
Subject: [DSN_KLR650] NKLR spark plug puzzles shade tree mechanic
Yesterday, a neighbor was having trouble getting his small push mower
started. I went to help and the first thing I did was hold the spark
plug wire out away fromt the plug while he cranked it. It started
immediately. Strangely, when I put the wire back on the plug the engine
would quit firing and begin to die. But I could hold the wire as far as
3/4 inch from the plug and the engine would run just fine. I could see
no spark at all but the sun was shinning, which probably explains that.
I pulled the plug out and the electrod in the middle was pretty much
burned up. I replaced it and it ran fine. But I have no clue why the
engine, with the old plug, would only run when the wire was held out
away from the plug.
Any ideas?
Robert Waters
[Non-text portions of this message have been removed]
[Non-text portions of this message have been removed]
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Messages in this topic (3)
6c.
Re: NKLR spark plug puzzles shade tree mechanic
Posted by: "Jeff Saline" salinej1@... jeffsaline
Mon Aug 3, 2009 8:39 pm (PDT)
On Mon, 3 Aug 2009 14:02:08 -0700 (PDT) Michael Martin
writes:
SNIP> Hi Robert,
SNIP> When you pulled the spark plug wire loose and held it away from the > plug, the voltage would not bleed off. It could keep rising to a > value that would jump the 3/4" gap you saw. At that voltage value, > it would also jump the gap at the spark plug electrode, causing the > engine to run.
<><><><><><> <><><><> <><><><><><> <><><><> Mike, Nice explanation. Thanks for taking the time to write that out. Best, Jeff Saline [Non-text portions of this message have been removed]> I hope this makes sense. > > Mike Martin, > Louisville, KY
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nklr spark plug puzzles shade tree mechanic
Remember the super ignition booster that J.C. Whitney used to sell?
You put it between your distributor cap and coil wire. It was yellow, and a
had a lightning bolt sticker on it. It did the same thing. there was a gap inside that
made the spark take a jump. Good old J.C. Whitney rocket science 101 :- )
Rick
A17
--- On Mon, 8/3/09, Jeff Saline wrote: From: Jeff Saline Subject: Re: [DSN_KLR650] NKLR spark plug puzzles shade tree mechanic To: mmartin36@... Cc: DSN_KLR650@yahoogroups.com Date: Monday, August 3, 2009, 10:27 PM On Mon, 3 Aug 2009 14:02:08 -0700 (PDT) Michael Martin writes: > Hi Robert, SNIP > When you pulled the spark plug wire loose and held it away from the > plug, the voltage would not bleed off. It could keep rising to a > value that would jump the 3/4" gap you saw. At that voltage value, > it would also jump the gap at the spark plug electrode, causing the > engine to run. SNIP > I hope this makes sense. > > Mike Martin, > Louisville, KY <><><><><><> <><><><> <><><><><><> <><><><> Mike, Nice explanation. Thanks for taking the time to write that out. Best, Jeff Saline ABC # 4412 South Dakota Airmarshal Airheads Beemer Club www.airheads. org The Beautiful Black Hills of South Dakota 75 R90/6, 03 KLR650, 79 R100RT . ____________ _________ _________ _________ _________ _________ _ Too many bills? Click here to simplify your life and lower your debt. http://thirdpartyof fers.juno. com/TGL2141/ fc/BLSrjpTIlMlUq OWk8rzLICFziujD9 JVUvV0HJroevXdi1 7DgiJ61kQM9PzS/ [Non-text portions of this message have been removed]
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