Another sparkplug quiz - The Jockey Journal Board

Go Back   The Jockey Journal Board > General Discussion > The Board

Reply
 
Thread Tools Search this Thread Display Modes
Old 06-13-2015, 02:19 PM   #1
oilfield money
Senior Member
 
Join Date: Apr 2013
Location: Pampa TX.
Posts: 196
Default Another sparkplug quiz

I have a new freshly built 58 6T with the iron head . I;m getting all the bugs worked out but the plugs are showing half good and the other half a little rich and when I say half , I mean like perfectly down the center . no matter how the plug goes in , The line is perfectly down the center of the terminal arm . The bike runs great but just a little curious whats going on ?
oilfield money is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 06-13-2015, 03:16 PM   #2
little d
Senior Member
 
little d's Avatar
 
Join Date: Dec 2007
Location: midwest
Posts: 2,905
Default Re: Another sparkplug quiz

Oil,
in a perfect world a combustion chamber would have a very even/uniform burn, this is rarely the case. Several things can affect this, combustion chamber shape, high dome pistons, sparkplug to valve location, the carb's ability to atomize the fuel, the fuel itself and even the port shape and direction comes into play here.

There is a video somewhere where they use a clear cylinder/head and slomo to film it, it shows what happens when ignition happens and shows the burn.

Just shooting from the hip here so take this for what it cost ya but, i would think what your seeing is the plug is not in a good position, only part of it is in a good burn and the rest of it is in a leaner area.

Are you using the right plugs? A shorter plug may pull the ignition point away from the good mix.

Are you running the right fuel to compression? Running a lower grade of gas with higher compression will let the gas burn before it fills the combustion chamber (this causes what is known as "ping" causing the piston to hit the cylinder wall.
__________________
"Apparently, any asshole can wrench on a newish, un-fuckered bike. Takes a goddamn genius to take this shit on."-Liam.
little d is offline   Reply With Quote
Old 06-13-2015, 03:32 PM   #3
Rob Axel
Senior Member
 
Rob Axel's Avatar
 
Join Date: Aug 2007
Location: Savanah Ga.
Posts: 1,596
Default Re: Another sparkplug quiz

Little D....please post that video if you find it...and your answer also helped me with my plug 'fouling' issue..I think Im getting oil into the chambers from old valve guilds...
I have also learned, each state has mandates on their fuels....The best gas here in Ga. is crap compared to the worst gas in South Carolina...
__________________
"The heart is happiest
When the head and the hand work together" - Jay Lenno
Rob Axel is offline   Reply With Quote
 
Old 06-13-2015, 04:00 PM   #4
oilfield money
Senior Member
 
Join Date: Apr 2013
Location: Pampa TX.
Posts: 196
Default Re: Another sparkplug quiz

Thanks little D , I;m using the correct plug the preunit iron head calls for a 1/2 reach and I'm running a tad bit warmer plug which is the NKG 6 just because the old thunderbirds are fairly low compression and ad least in my mind I think it runs better . What to me is odd is that the overly rich line is perfectly down the center and the other half is that nice tan color
oilfield money is offline   Reply With Quote
Old 06-13-2015, 05:07 PM   #5
richbob
Senior Member
 
richbob's Avatar
 
Join Date: Sep 2011
Location: Toscana
Posts: 2,270
Default Re: Another sparkplug quiz

I'm running a 5
round town
6 was fouling but on a 3 hour motorway thrash(70mph +) no fouling but still looked rich.(I'm twin carbs 26mm Kehihn)
__________________
Rush Rush to the Yayo. Blondie

"Ultimately were all dead men"(Oliver Reed.Gladiator)
richbob is offline   Reply With Quote
Old 06-13-2015, 05:23 PM   #6
Elffors
Senior Member
 
Elffors's Avatar
 
Join Date: Jun 2011
Location: Uppharad Sweden
Posts: 1,153
Default Re: Another sparkplug quiz

This thread is useless without pics
__________________
I support Rolling death Hawai!
IG @the_elffors
Elffors is offline   Reply With Quote
Old 06-13-2015, 07:04 PM   #7
VonWegener
Senior Member
 
VonWegener's Avatar
 
Join Date: Nov 2009
Location: Apple Valley
Posts: 3,276
Default Re: Another sparkplug quiz

And just to throw more fun into the mix. There are counterfeit NGK plugs being sold that are supposed to have problems. And I had Problems with brand new champions where on a V8 one new plug was just bad. Got a new one and it was bad also. That was the end with Champions for me.
__________________
*
Your friendly neighborhood W&W Cycle Germany, Paughco and V-Twin dealer

VonWegener is offline   Reply With Quote
Old 06-13-2015, 10:13 PM   #8
JAWS
Senior Member
 
JAWS's Avatar
 
Join Date: Aug 2007
Location: la la land
Posts: 8,513
Default Re: Another sparkplug quiz

Did you index your plugs? With the plug centered between both valves and the strap centered, the intake side will be cleaner. Fuel is a solvent.
__________________
60% of the time, it works every time...
JAWS is offline   Reply With Quote
Old 06-13-2015, 11:41 PM   #9
oilfield money
Senior Member
 
Join Date: Apr 2013
Location: Pampa TX.
Posts: 196
Default Re: Another sparkplug quiz

I never indexed them I just randomly run them down tight . But what would be the chances that they landed that way with the center strap centered up between the intake and exhaust valve ? But I will change the plugs and mark them to see how they land when they bottom out . I agree a pic would really help but that's another unknown I need to learn how to do
oilfield money is offline   Reply With Quote
Old 06-15-2015, 07:30 AM   #10
little d
Senior Member
 
little d's Avatar
 
Join Date: Dec 2007
Location: midwest
Posts: 2,905
Default Re: Another sparkplug quiz

Rob,
I looked last night for it but couldn't find it, sorry, wish I was better at this internet thing but, Ill keep looking. Anyway, it showed what I described, the fuel/air mixture filling one side of the chamber, being compressed and firing off. With the slomo, you could actually see the piston moving and hitting the side of the cylinder, it was a Aw Ha moment for me.

Von,
I had the same issue with my Wife's 340 Mag, 1 weak cylinder I chased for what felt like forever, swapped out the plug and bingo. Lesion learned.


Jaws is right, fuel makes a hell of a cleaner. When I'm dialing in a motor, I pull the clutch in and kill it instead of letting it coast down to minimize the washing down.
__________________
"Apparently, any asshole can wrench on a newish, un-fuckered bike. Takes a goddamn genius to take this shit on."-Liam.
little d is offline   Reply With Quote
Old 06-15-2015, 12:27 PM   #11
Rob Axel
Senior Member
 
Rob Axel's Avatar
 
Join Date: Aug 2007
Location: Savanah Ga.
Posts: 1,596
Default Re: Another sparkplug quiz

Von....funny you say "bad new plugs".... I've got a thread somewhere on here where my wife "fixed" my bike...by asking "can new spark plugs be bad" when I was chasing a gremlin in my motor...
__________________
"The heart is happiest
When the head and the hand work together" - Jay Lenno
Rob Axel is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


All times are GMT -5. The time now is 08:32 AM.