Importance of the correct plug??

[CamYZ125]

How important is it to use the 'correct' plug in your bike?? The other day, I was riding with my best friend and I fouled a plug in my '00 YZ125. He had his truck, tools, and extra plugs for his bike, but I didn't have any of my stuff. So we decided to put one of his plugs in my bike.... I had been using B9ES plugs (that's what the previous owner was using, so I continued to use it) and my friend had BR8ES plugs. Now, my bike ran just like it had with the other type plug- I really hadn't expected it to make a difference, but is there any reason that I shouldn't have used the different plug? I'm not exactly sure what all the numbers and letters mean- I'm guessing one is for a certain heat range, maybe someone can explain that a little more in depth?? Also, I just looked in my manual, and it says to run a BR9EG... are there any consequences to running a B9ES, or even the BR8ES I used last weekend??? Thanx in advance for any information concerning this!

 

[jmics19067]

I believe the "B" designates the size of the plug ie 14mm thread 3/4" reach ?
The "R" stands for resistor , for the 39 cents extra per plug extra buy the R.

the "9" is the heat range going to an "8" is one step hotter. which is to say that it retains the heat at the tip of the plug longer.

The " EG" , "ES", "EV" etc is the type of metal that they use for the plug,copper , gold ,platinum can't remember which one is which though.

since you fouled a b9es I would venture to say that running a br8es probably wont cause any damage but.... running a hotter plug could. Or should I say running too hot of a plug will.

If my manual told me to have a br9eg I would buy the 2 or 3 br9es for the same money. When I learn how to read a plug and jet correctly then I would start looking at the other options that my conditions would warrant.

Keep your eyes open and read any and all posts what I gave you is not even the tip of the iceberg to understanding spark plugs

 

[whyz]

There's alittle info here too about plugs and even says something about why

the resister type by >Clicking here

My sons YZ (stock plug) is aBR9EG, But weve been using those BR8ES plugs

You can buy 2-3 plugs for the price of 1 EG plug.

 

[Fark]

Someone said it before, the key is to buy cheap and buy often. You need to install a new plug to get accurate mixture readings anyway.