KTM Duke 390 Forum banner
1 - 20 of 49 Posts

·
Registered
Joined
·
264 Posts
Discussion Starter · #1 ·
The Duke using a not well known spark plug type BOSCH Super R6 VR5 NE.

Breaking it down:

http://www.boschautoparts.com/BAP_Technical_Resources/Spark Plugs/SP_NumberSyst_CHART_12.pdf

V = M12x1.25
R = resistor
5 = heat range
N = 26.5 mm thread depth, 4mm electrode lenght
E = electrode material is nickel ytttrium

The equivalents are not very obvious for such a new plug, however it appears the Duke 200 uses the same plug and the NGK Iridium equivelant for the Duke 200 is NGK Spark Plug (LKAR8A-9). If someone can confirm this I'd appreciate it.
 

·
Registered
Joined
·
573 Posts
same here ... i'm looking for Iridiums alternatives ...

The Duke using a not well known spark plug type BOSCH Super R6 VR5 NE.

Breaking it down:

http://www.boschautoparts.com/BAP_Technical_Resources/Spark Plugs/SP_NumberSyst_CHART_12.pdf

V = M12x1.25
R = resistor
5 = heat range
N = 26.5 mm thread depth, 4mm electrode lenght
E = electrode material is nickel ytttrium

The equivalents are not very obvious for such a new plug, however it appears the Duke 200 uses the same plug and the NGK Iridium equivelant for the Duke 200 is NGK Spark Plug (LKAR8A-9). If someone can confirm this I'd appreciate it.
 

·
Registered
Joined
·
1,086 Posts
Would you guys swap plus to something "better" right from the start or wait it out till their in need of changing to upgrade to what can be better?
 

·
Registered
Joined
·
573 Posts
it depends, if it's better and do not cost an arm n leg, i'll want to have it installed right away ... :D:D:D

Would you guys swap plus to something "better" right from the start or wait it out till their in need of changing to upgrade to what can be better?
 

·
Registered
Joined
·
1,086 Posts
Can anyone confirm that it is an iridium plug? Usually it says this on the plug, right? Not that I would suggest pulling it out just for this.
 

·
Registered
Joined
·
264 Posts
Discussion Starter · #9 ·
Can anyone confirm that it is an iridium plug? Usually it says this on the plug, right? Not that I would suggest pulling it out just for this.
Actually not all of them will say it on the plug but the centre electrode is usually what I look at. An Iridium or other precious metal electrode is usually about 1/4 mm thick compared to the standard electrode which will be around 1.5mm thick.
 

·
Registered
Joined
·
573 Posts
the stock plug IS NOT Iridium ... it,s just a lawnmower plug from Bosch ... nothing more nothing less ... the tip is as per norms
 

·
Registered
Joined
·
817 Posts
A hotter plug in an already hot engine just doesnt compute with me, Ive also seen what Irridium plugs do to valves that arent built for them.
 

·
Registered
Joined
·
40 Posts
just curious compare data between spark plus bosch VR5NE substitution are NGK LKAR8A-9

source :NGK 4786 LKAR8A-9 Nickel Spark Plug

on the right cooller
Denso : 14 - 16 - 20 - 22 - 24 - 27 - 31
NGK : 4 - 5 - 6 - 7 - 8 - 9 - 10 more cold
Champion : 14/16 - 11/12 - 9/10 - 7/8 - 6/61/63 - 4/59 - 57 - 55
BOSCH : 9 - 8 - 6/7 - 5 - 4 - 3 - 2 more cold

So...NGK more cooler I bet...will try on my duke 200
 

·
Registered
Joined
·
573 Posts
it good to try it out and share us your findings. im keeping my finger crossed that LKAR8A-9 and LKAR8AI-9
 

·
Registered
Joined
·
40 Posts
it good to try it out and share us your findings. im keeping my finger crossed that LKAR8A-9 and LKAR8AI-9
I had been tried using LKAR8A-9 on D200 until now and it's ok .... and then found this cross reference heat range between ngk, bosch, denso

https://www.ngk.com/learning-center/article/225/heat-range-conversion-chart
(NGK bigger number colder, Bosch Bigger number more hotter)

NGK---Bosch
*7 ---- 5
*8 ---- 4

So....LKAR8A-9 is colder 1 step than VR5NE

specs are same with VR5NE
Plug Specifications



source :NGK 4786 LKAR8A-9 Nickel Spark Plug
 

·
Registered
Joined
·
67 Posts
Can someone please guide me through removing the spark plug. I can't get the socket to grip the plug, or even find it. There seems to be a spongy thing in the way. I can feel the plug with my finger.
 

·
Registered
Joined
·
161 Posts
Can someone please guide me through removing the spark plug. I can't get the socket to grip the plug, or even find it. There seems to be a spongy thing in the way. I can feel the plug with my finger.
The plug spanner that came with the kit is crap, best buy a 3/8 drive 14mm plug socket (thats 14mm across the flats) a 3/8 uni joint and a 3/8 short extension, with this combination it's easy to remove the plug and refit it.
 

·
Registered
Joined
·
4 Posts
I had been tried using LKAR8A-9 on D200 until now and it's ok .... and then found this cross reference heat range between ngk, bosch, denso

https://www.ngk.com/learning-center/article/225/heat-range-conversion-chart
(NGK bigger number colder, Bosch Bigger number more hotter)

NGK---Bosch
*7 ---- 5
*8 ---- 4

So....LKAR8A-9 is colder 1 step than VR5NE

specs are same with VR5NE
Plug Specifications



source :NGK 4786 LKAR8A-9 Nickel Spark Plug
On the NGK website right on the bottom there is a link to an advanced search where you can put in specs,

http://www.ngk.com/Search.aspx?ptn=Spark+Plug

Putting in the specs above throws up 3 spark plugs which are compatible..

LKAR8A-9
LKAR8AI-9
LZKAR7A

Interestingly the last option will probably be more suitable considering that the NGK heat range no 7 is a better match to Boschs heat range no 5. Everyone here in India seems to be using the LKAR8 though so if anyone else can chip in with info on this would appreciate it.
 

·
Registered
Joined
·
47 Posts
So in conclusion, is the LKAR8AI-9 the iridium plug for the 390 Duke.?

Was there a conclusion to this?

Any further thoughts on this??
 
1 - 20 of 49 Posts
Top