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KTM Spark Plug Fitment Chart

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Table of Contents

KTM Spark Plug Fitment Chart

 

ManufacturerModelStandard PlugIridium PlugElectrode Gap
KTM1050 ADVENTUREOuter LMAR7DI-10Inner LKAR9BI-101.0 MM
KTM1090 ADVENTURE (EURO 4)Inner LKAR9BI-10Outer LMAR7DI-101.0 MM
KTM1090 ADVENTURE R (EURO 4)Inner LKAR9BI-10Outer LMAR7DI-101.0 MM
KTM1190 ADVENTURENGK Inner LKAR9BI9NGK Outer LMAR7A-90.8-0.9 MM
KTM1190 ADVENTURE RNGK Inner LKAR9BI9NGK Outer LMAR7A-90.8-0.9 MM
KTM1190 RC8NGK LKAR9BI9 0.8-0.9 MM
KTM1190 RC8 RInner NGK LKAR9BI9AB’11 AUß. LMAR7A90.8-0.9 MM
KTM125 DUKENGK LKAR8A-9 0.8 MM
KTM125 DUKE (EURO 4)NGK LKAR8A-9  
KTM125 EXCNGK BR9EIX  
KTM125 EXCNGK BR9ECMVX  
KTM125 LC2 ENDURONGK BR9ES (BIS 00)NGK BR8HS (From 00-)0.6 MM
KTM1290 SUPER ADVENTUREOuter LMAR7DI-10Inner LKAR9BI-10 
KTM1290 SUPER ADVENTURE R (EURO 4)Outer LMAR7DI-10Inner LKAR9BI-101.0 MM
KTM1290 SUPER ADVENTURE S (EURO 4)Outer LMAR7DI-10Inner LKAR9BI-10 
KTM1290 SUPER ADVENTURE T (EURO 4)Outer LMAR7DI-10Inner LKAR9BI-101.0 MM
KTM1290 SUPER DUKE GTOuter LMAR7DI-10Inner LKAR9BI-10 
KTM1290 SUPER DUKE GT (EURO 4)AUS.NGK LKAR9BI-10INN.NGK LMAR7DI-101.0 MM
KTM1290 SUPER DUKE RNGK LKAR9BI9 InnerNGK LMAR7A9 Outer0.8-0.9 MM
KTM1290 SUPER DUKE R (EURO 4)Outer LMAR7DI-10Inner LKAR9BI-100.9 MM
KTM1290 SUPER DUKE R (EURO 4)Outer LMAR7DI-10Inner LKAR9BI-10 
KTM1290 SUPER DUKE R (EURO 4)   
KTM1290 SUPER DUKE R / SPECIAL EDITIONNGK LKAR9BI9 InnerNGK LMAR7A9 Outer0.9 MM
KTM200 DUKENGK LKAR8A-9 0.8 MM
KTM200 EXCNGK BR8EG–0.6 MM
KTM250 EXCNGK BR8ECM 0.6 MM
KTM250 EXC RACINGNGK DCPR8ENGK DCPR8EIX0.6 MM
KTM300 EXCNGK BR8ECMNGK BR8ECMIX0.6 MM
KTM350 LC4 ENDURONGK D8EANGK DR8EIX 
KTM380 EXCNGK BR8ECM 0.8 MM
KTM390 ADVENTURE (EURO 4) BOSCH VR6NEU1.0 MM
KTM390 DUKENGK LKAR8A-9 0.8 MM
KTM390 DUKE (EURO 4)NGK LKAR8A-9  
KTM400 EXC RACINGNGK DCPR8ENGK DCPR8EIX0.6 MM
KTM400 EXC RACINGNGK CR8EKNGK CR8EIX0.6 MM
KTM450 EXC RACINGNGK DCPR8ENGK DCPR8EIX0.6 MM
KTM520 EXC RACINGNGK CR8EKNGK CR8EIX0.6 MM
KTM525 EXC RACINGNGK DCPR8ENGK DCPR8EIX0.6 MM
KTM530 EXC RACINGNGK LKAR8A-9 -09NGK LKAR8AI-9 10-0.9 MM
KTM600 GS   
KTM620 E DUKENGK DR8EANGK DR8EIX0.7 MM
KTM620 LC4NGK D8EANGK DR8EIX0.6 MM
KTM620 LC4 LSENGK DR8EANGK DR8EIX0.7 MM
KTM620 LC4-E ADVENTURE / RALLYENGK DR8ENGK DR8EIX0.7 MM
KTM625 SMC SUPERMOTONGK DPR8ENKG DPR8EIX0.6 MM
KTM625 SXC HARDENDURONGK DCPR8ENGK DPCR8EIX0.6 MM
KTM640 LC4 ADVENTURENGK DCPR8E 0.6 MM
KTM640 LC4 DUKE IINGK DR8EA (99-01)NGK DCPR8E (02-)0.7 MM
KTM640 LC4 ENDURONGK DCPR8ENGK DCPR8EIX0.6 MM
KTM640 LC4-E ADVENTURE RNGK DR8EA 0.7 MM
KTM640 LC4-E SUPERMOTONGK DR8EANGK DR8EIX0.7 MM
KTM640 SUPERMOTONGK DCPR8ENGK DCPR8EIX0.6 MM
KTM660 SMCNGK DCPR8ENGK DCPR8EIX0.9 MM
KTM660 SMCNGK DCPR8ENGK DCPR8EIX0.9 MM
KTM690 DUKENGK LKAR8AI-9 0.9 MM
KTM690 DUKEInner LKAR8BI-9Outer LMAR7A-90.9 MM
KTM690 DUKENGK LKAR8BI9 InnerNGK LMAR7A9 Outer0.9 MM
KTM690 DUKE (EURO 4)Outer LMAR7DI-10Inner LKAR9BI-101.0 MM
KTM690 DUKE RNGK LKAR8BI9 InnerNGK LMAR7A9 Outer0.9 MM
KTM690 DUKE R (EURO 4)Outer LMAR7DI-10Inner LKAR9BI-101.0 MM
KTM690 DUKE / RNGK LKAR8AI-9 0.9 MM
KTM690 ENDURONGK LKAR8AI-9 0.9 MM
KTM690 ENDURO ROuter LMAR7DI-10Inner LKAR9BI-10 
KTM690 ENDURO RNGK LKAR8AI-9 0.9 MM
KTM690 ENDURO RNGK LKAR8AI-9 0.9 MM
KTM690 ENDURO RNGK LKAR8BI9 InnerNGK LMAR7A9 Outer0.9 MM
KTM690 SMCNGK LKAR8AI-9 0.9 MM
KTM690 SMC RNGK LKAR8AI-9 0.9 MM
KTM690 SMC RNGK LKAR8BI9 InnerNGK LMAR7A9 Outer0.9 MM
KTM690 SMC R   
KTM690 SUPERMOTONGK LKAR8AI-9 0.9 MM
KTM790 ADVENTURENGK LMAR9AI-10NGK LMAR9AI-101.0 MM
KTM790 ADVENTURE RNGK LMAR9AI-10NGK LMAR9AI-101.0 MM
KTM790 DUKENGK LMAR9AI-10NGK LMAR9AI-10 
KTM890 DUKE RNGK LMAR9AI-10 1.0 MM
KTM950 ADVENTURE / SNGK CR8EKNGK CR8EIX0.7 MM
KTM950 SUPER ENDURO RNGK CR8EKNGK CR8EIX0.7 MM
KTM950 SUPERMOTONGK CR8EKNGK CR8EIX0.7 MM
KTM950 SUPERMOTO RNGK CR8EKNGK CR8EIX0.7 MM
KTM990 ADVENTURENGK LKAR8BI9 0.9 MM
KTM990 ADVENTURE RNGK LKAR8BI9 0.9 MM
KTM990 ADVENTURE / SNGK DCPR8ENGK DCPR8EIX0.6 MM
KTM990 SUPER DUKENGK DCPR8ENGK DCPR8EIX0.6 MM
KTM990 SUPER DUKENGK KR8DI 0.8 MM
KTM990 SUPER DUKE RNGK KR8DI 0.8 MM
KTM990 SUPER DUKE RNGK LKAR8AI-9 0.8 MM
KTM990 SUPERMOT0 / ABSNGK LKAR8BI9 0.8 MM
KTM990 SUPERMOTONGK KR8DI 0.8 MM
KTM990 SUPERMOTO RNGK KR8DI 0.8 MM
KTM990 SUPERMOTO TNGK KR8DI 0.8 MM
KTMFREERIDE 250 RNGK BR7ES 0.6 MM
KTMFREERIDE 350NGK LMAR9AI-10 1.0 MM
KTMRC 125NGK LKAR8A-9  
KTMRC 125 (EURO 4)NGK LKAR8A-9  
KTMRC 390NGK LKAR8A-9  
KTMRC 390 (EURO 4)NGK LKAR8A-9  

Reading your spark plug

The image of the spark plugs above shows four common conditions that you’ll find your spark plugs in. From left to right the plugs are Normal, Rich, Lean and Very Lean. Full descriptions below.

Before you throw your old spark plug in the bin, check them to get an understanding of how well your engine is running.

Normal condition

If the plug is brown or light grey your can assume your engine is in good condition and the spark plug is functioning well. Even when a plug is in good condition small deposits will accumulate. This is normal.

Rich

There are many different causes of spark plug fouling. If the plug has oil on it, then it’s oiling up and may not work efficiently, potentially causing a misfire or stuttering under hard acceleration. If it’s just dark or black the bike could be running too rich. A heavy accumulation of carbon on the nose can cause a leakage path to earth. This can cause misfires and poor engine starting.

Causes: The causes of this can be anything from, a rich fuel mixture, too much choke, long periods of low-speed riding or idling in traffic, a blocked air filter or the plug’s heat range is too cold.

Lean

If the engine is running lean then the spark plug has a grey colour but you’ll probably see some black deposits on there too.

Causes: Insufficient cooling, blocked injectors, too lean a fuel mixture

Very Lean

If the engine is running dangerously lean the whole plug tip will be grey or white. If the temperature is over 850-degrees, pre-ignition may occur. Engine power will be reduced and you risk piston damage.

Causes: Insufficient cooling, blocked injectors, too lean a fuel mixture, ignition timing too far advanced, excessive combustion chamber deposits.

Motorcycle Spark Plug Fitting Guide + Tips

  • When you’ve removed your spark plugs, check the condition of the threads in the cylinder head and put a cloth over the cylinder head if you’re going to leave it exposed.

  • Install each spark plug by hand until you have wound the thread a couple of turns. This reduces the chances of you cross-threading the plug.

  • Torque the spark plug up to your manufacturer’s recommended settings. If you don’t have a torque wrench, then get the plug hand tight and then add a ½ turn for a plug with a gasket, and more like a ¼ turn for a tapered spark plug. Over-tightening can snap the spark plug – a nightmare.

  • Don’t put any lubricant or thread lock on the spark plug. Inspect your spark plug caps and replace if required.

Iridium Spark Plug vs Standard

A regular spark plug uses a copper central electrode whereas an iridium spark plug uses, you guessed it, iridium.

The metal in a spark plug has a single purpose: to channel the electrical energy through the spark plug. Iridium is far harder than copper and this allows the spark plug manufacturers to create a plug with a sharper ‘tip’ which better focuses the spark around the centre electrode without compromising its service life.

A typical copper spark plug will last around 20,000 miles and most get changed at a major service (usually around 16,000 miles) but an iridium spark plug will be good for around 50,000 miles and you do see people running them to 100,000 miles with no issues.

Copper is generally seen as being the best metal to use in terms of conductivity but iridium plugs are seen as premium as they last longer than standard plugs and can be built with smaller tolerances. Iridium spark plugs also have lower voltage requirements, meaning they perform better when starting and idling and some manufacturers also claim they offer a better throttle response.

Iridium plugs are more expensive than copper but seeing as they last longer and offer a more consistent performance throughout their lifetime, many bikes opt for an iridium ‘upgrade’.

Spark Plug Removal

 

If you’re going to be doing any sort of work on the bike, treat yourself to a decent set of tools. Most of mine are from the Halfords Advanced range (formerly called Professional).

They have a lifetime guarantee and for an amateur bodger like me, they’re perfect.

The image above shows their 100pc range, which costs around £125. It’s a comprehensive bit of kit and includes a 1/4″, 3/8″ and 1/2″ drive, alongside plug sockets, universal joints and a wobble bar. Pretty much everything you’ll ever need for any motorcycle maintenance job.

Motorcycle Spark Plug Removal Tools

If you’ve not changed your plugs before, give yourself a couple of hours to complete the task. Here are the essentials you need for smooth re-plugging:

Your owner’s manual
You’ll need this to help you find the location of your spark plugs and how to access them. This may sound simple but often the manual offers up some time-saving tips for your particular model.

A spark plug socket
You’ll need a deep socket. A decent tool kit will have them. Don’t get confused between thread size and socket size. Motorcycle spark plug socket sizes are usually 16mm, 18mm or 20.6mm (21mm will do). Whereas the threads are usually 10mm, 12mm or 14mm. When it comes to motorcycles, access is usually tricky, so my tip is to buy a magnetic spark plug socket like this one. Once you’ve undone your old plug, this will help you remove it with far less effing and jeffing.

A wobble socket / universal joint
You’ll be lucky if there’s a straight line to your spark plug, so a universal joint will get you the angle you need to apply some torque. Again, a decent toolset will have one.

A 3/8″ drive
You could buy a specific spark plug T-bar but your home tool kit will have the drive you need to connect to your plug sockets.

A spark plug gap gauge
This nifty little tool only costs a few quid and will help you set the correct gap for your spark plug. However, modern plugs are almost all motorcycle-specific fit and so they come ‘pre-gapped’ and you won’t need to touch them. If you’re running a classic bike, you’ll probably need to set your gap and if your bike’s not running right, a gap tool can help you rule out a potential incorrect gap issue.

A torque wrench
It’s important to properly torque your spark plugs. Too tight and you’ll risk snapping it or it will be a mission to remove. Too loose and you risk an electrical short. Your owner’s manual will have the correct torque settings.

Motorcycle Spark Plug FAQ

What are the common motorcycle spark plug sizes?
Thread diameters of 10mm, 12mm, and 14mm are the most common. In fact, when it comes to motorcycles, it's rare to find any other sizes in use.

How long should a spark plug last?
Motorcycle spark plugs usually last around 16,000 miles, or at least this is when most manufacturer service schedules recommend you change them. That's typically once every other major service. However if you use Iridium spark plugs they will last a lot longer, usually well over 30,000 miles.

How do you clean motorcycle spark plugs?
Just remove the plug and use a wire brush to gently brush off any deposits on the electrode. Don't use a power tool, by hand is all that's required.

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