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Wrong plug in my bike

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Hello people

I have a bike shop close to where i live , my bike is an EXC200 from 2007 , according to the manual I should put an NGK BR8EG (54331093310) , unfortunately the shop only has NGK BR7ES ( which is for EXC250/300 04-15 )

What happens if I put the 300 plug inside ? does it run ? does it run well ?

I am asking because a friend recommended me so , he has a 250EXC from 2010 , and he said it is ok to put that in .

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2 hours ago, endurocross said:

Hello people

I have a bike shop close to where i live , my bike is an EXC200 from 2007 , according to the manual I should put an NGK BR8EG (54331093310) , unfortunately the shop only has NGK BR7ES ( which is for EXC250/300 04-15 )

What happens if I put the 300 plug inside ? does it run ? does it run well ?

I am asking because a friend recommended me so , he has a 250EXC from 2010 , and he said it is ok to put that in .

The 7 is a hotter heat range, you wont notice any difference , but it retains more heat to burn off deposits. The only potential issue , is if you retain to much heat , it can cause melt down issues.

If your 8 plugs tend to run dark or foul easy, then your probably safe with the 7.

 

On a side note, my cr500 ran 8's, every month it would cold foul, but I didn't like any jetting changes to cure that, so I went to a 7bres, plugs then went years between replacement

Edited by Spud786
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Hi, B = thread size of 14mm, R = resistor type, number is heat range, E = thread reach. So the different plug will fit and heat range is determined by amount of the central electrode which is exposed. The more there is exposed to glow then the 'hotter' the plug obviously. I certainly wouldn't go any hotter than a 7 but should be fine. (We run 10s in our race tuned 125s which are real cold plugs !) If you rag your exc then try and get an 8. Bob.

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12 hours ago, 7Tktm said:

Hi, B = thread size of 14mm, R = resistor type, number is heat range, E = thread reach. So the different plug will fit and heat range is determined by amount of the central electrode which is exposed. The more there is exposed to glow then the 'hotter' the plug obviously. I certainly wouldn't go any hotter than a 7 but should be fine. (We run 10s in our race tuned 125s which are real cold plugs !) If you rag your exc then try and get an 8. Bob.

Hi Bob , aka 7Tktm

I was just about to post this link http://www.math.uwaterloo.ca/~rblander/NGK.txt, but you beat me ahead , 7 means hotter , and we all know that electricity flows harder on hotter wires , and easier on cooler wires ( not too cold anyways )  , and it is ok for the EXC250/300 which have a bigger stator , but for 200 it is not quite the best .

Also G means "racing use" and  S "standard 2.6mm centre electrode" , more for the BR8EG plug .

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Too much science lol. We use cold plugs to prevent pre ignition, but the engines are worked very hard.

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The heat range of a sparkplug is determined by how much material is on the threaded body of the sparkplug. The colder plugs will have more material on the threaded portion of the plug and hotter plug will have less material on the threaded body of the plug. It is how heat is transfered the cooling jacket in the cylinder head. the more material there is, the better the heat transfer. it is not about spark intensity. 7TKTM is also correct with the length of the center electrode. I have never thought about it that way

Little Jeff

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Ive been using the B8ES cost less and more available.

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