Engine Trouble Best spark plug for a YD100

[ImpulseRocket]

I have a YD100 so If I want to check the depth I have to take it all apart which I’m feeling a bit lazy for but I’ll come around.

Or you could just take the spark plug out lol

 

[Guest_5]

Or you could just take the spark plug out

Oh I thought you meant check from the inside sorry.

 

[ImpulseRocket]

Oh I thought you meant check from the inside sorry.

Nah no need to get that involved. All you are looking to do is see how deep the threads are in the head vs how long the threads are on the spark plug. Super simple 2 minute job.

 

[motoredjosh]

This is a common misconception in the motorized bike world. Changing the spark plug heat range to a "hotter" plug does not change how hot the engine runs. I will spare you all the mumbo jumbo but the simplest explanation is that the plugs operate their best in a given thermal range and the heat range for a given motor is selected based on that range. Too cold and the plug cannot self clean and fouls easily. Too hot and it can fail to allow spark to fire from too high of a resistance AND potentially cause pre-ignition.

If you want to understand it better then this is a great simple explanation. https://www.denso.com/global/en/pro...e-parts-and-accessories/plug/basic/heatrange/

it certainly can. a spark plug outside of the correct heat range can cause pre ignition and over heating and effect overal engine operating temperatures.

 

[ImpulseRocket]

it certainly can. a spark plug outside of the correct heat range can cause pre ignition and over heating and effect overal engine operating temperatures.

A spark plug will not cause overheating. The overheating occurs because of the pre-ignition which is caused by the incorrect heat range. Overheating is the least of your issues if you are experiencing pre-ignition. Regardless of all of that nonsense the point still stands... Putting in a B6HS in place of a B8HS plug will not magically make the engine run hotter. End of story.

 

[motoredjosh]

a spark plug outside of the correct heat range can cause overheating

 

[motoredjosh]

A spark plug will not cause overheating. The overheating occours because of the pre-ignition which is caused by the incorrect heat range. Overheating is the least of your issues if you are experiencing pre-ignition. Regardless of all of that nonsense the point still stands... Putting in a B6HS in place of a B8HS plug will not magically make the engine run hotter. End of story.

i dont know if you're serious or trolling lol

 

[ImpulseRocket]

i dont know if youre serious or trolling lol

I am dead serious. If you think just increasing the heat range of the plug makes an engine run hotter by default there is no helping you. I can also tell that no matter what I say you won't accept basic physics for what it is. The heat range has to do with how deep the gas pocket and far the porcelain extends over the center electrode which directly affects the rate at which the plug can shed heat during operation. That's it. It doesn't make the engine run hotter unless you are too far out of the temperature range for the engine during it's operation - thus a running issue is created. If my engine is running a B8HS and I install a B6HS and the B6HS is within the ideal thermal operating range during the engines operation (thus meaning the plug is not causing a running issue of any kind) my engine will not miraculously run hotter because of it. Not sure if I can explain it any simpler than that.

If you want to say anything to the contrary of that I invite you to post a reputable source.

I also invite you to read through this simple guide from a major spark plug manufacturer on what Heat Range actually is. https://www.denso.com/global/en/pro...:text=A spark plug only functions,C and 950°C.

 

[ImpulseRocket]

Just because I love beating a dead horse...

 

[DAMIEN1307]

If my engine is running a B8HS

Hi ImpulseRocket,

Are you running the NGK-BR8HS plug in your Phantom???...I am running it in mine and it seems like it is the perfect plug to burn in these Phantoms,,,Beautiful chocolate/coffee brown colour when I recently checked...I am also, at least during breakin, running the needle valve two grooves richer than I normally would since it appears these things like to run a little richer, (I'm at a 4500 ft altitude), I am guessing it might be due to the reed valve.

I am used to running my bikes at full lean because of my altitude, but wondering where I should finalise my needle valve postion once I have fully completed breakin on this Phantom as it seems to be a different little beastie than most of the CGs...It's presently in the middle groove.