Spark Plug

[Crimeidy26]

I was reading through the NGK Plug Book and it recommended at BR9ES plug and thats what was in the bike when i bought it a few weeks ago and it ran fine but when i pulled it off it seemed way to wet and i ran a BR8ES and it doesn't seem to make a difference in power but keeps the plug much cleaner. I went to the hotter plug to try and diagnose the problem before rejetting the carb. The bike starts and Idles with both plugs but since running the BR8ES instead of the 9 it keeps the plug much cleaner. Is the BR8ES an acceptable plug to use in this bike eventhough NGK and every site recommends a BR9ES? Any responses and opinions will be greatly appreciated.
Thanks
Jarrod :bang:

 

[G. Gearloose]

Correct, the 8 is best to begin your jetting.
History shows the 9 to be too cold unless you wot for extended periods on the sand or ice.

 

[glad2ride]

The stock plug is a B9ES. If you are out cruising trails, you may not generate enough heat to keep a "9" heat range plug cleaned off. Try the B8ES (Oreilley Auto parts has them cheap). It should look like a cup of hot cocoa.

You have to have the correct heat range plug before you start working on the jetting.

Good luck with your great bike!

 

[charlie21]

I have a 97 rm 125 and im running a br8es but it seems to bet wet alot of the time i pull it could i try a br7es or is that not a good thing to do.

 

[mudpack]

I have a 97 rm 125 and im running a br8es but it seems to bet wet alot of the time i pull it could i try a br7es or is that not a good thing to do.

Two stroke plugs will always appear "wet", that's normal.
You should only go to a hotter range plug if you are fouling plugs consistently.
NOTE: a fouled plug is one that will not produce spark, not one that looks wet.....................

 

[Rich Rohrich]

Two stroke plugs will always appear "wet", that's normal.

A two-stroke plug should NEVER look wet if the plug is the correct heat range and the jetting is correct. If the plug looks wet you have a problem that needs to be corrected.

This is what a two-stroke plug should look like :

This is a plug with nearly perfect jetting. The fuel is Phillips B35 unleaded, oil is Phillips Xamax mixed at 18:1 ratio. It came out of a 150cc MX bike ridden on a tight track by a really slow guy ( ME :whoa: ) .

Even with a lot of oil in the mix the plug should be clean looking if it's running at the right temperature.

If a plug looks wet it's running too cold, and will tend to foul or at least misfire under load, which is much more difficult to track down.

Two-strokes that are used for slower speed trail riding usually need fairly lean jetting on the pilot and needle along with hotter plugs, compared to the factory "safe" settings they come with.

The plug is an excellent indicator of how well the engine is performing, and if it's wet you are leaving a lot of throttle response and power on the table.

 

[HAYSHAKER170]

Another option is a Iridium plug. I think BR9EIX would be the equivalent to BR9ES. I use one the entire year with no fouling. Of course jetting correctly is the key.

 

[glad2ride]

Stock is B9ES, I believe. Try a B8ES.

It will never run right without the correct heat range plug.

Some guy named Rich Rohrich educated me on it about 6 years ago. :-)