Jump to content
Sign in to follow this  

fouling spark plugs

Recommended Posts

i know this isn't a two stroke forum but my yz 85 is fouling spark plugs like crazy i am running a BR10EG spark plug. i know what you guys are going to say ride it harder i know that the bike is ment to be revved out i ride the bike hard but the plug keeps fouling i am mixing the bike 40:1 and that is still too rich what kind of plugs are you guys running or i was thinking about rejetting it the stock main jet is a 138 i think i might try a 136 or 134 or should i just change the plug?

thanks

Share this post


Link to post
Share on other sites

You may need to re-jet. When is it fouling the plugs? On the bottom when it is getting lugged around? On the top at WOT, or just around the middle? There are several thigns that could be going on. How much time is on the bike? Has it always done this? Is it a new bike and done it from the start?

Share this post


Link to post
Share on other sites

the bike is an 02 i bought it used but the kid who had it before me only put about 5 hrs tops on it i have had it for 3 weeks and i have about 20 hrs seat time on the bike and yes the bike has been doin it from the start

Share this post


Link to post
Share on other sites

Get a hand full of new plugs, a couple of smaller mains, and some one who has experience jetting a bike to get you started. If you get it too lean you can cause a big bill. It's not to difficult to accomplish, just takes some time and a know how to read the plug. I would suggest getting a little help, but in the mean time you could just pull the slide and raise the clip on the needle (lower the needle by raising the clip a goove or two). This will clean it up a little, and may fix it enough to keep it from fouling. If you have never jetted a bike I would strongly suggest getting a hand rather than doing it all your self. :cry:

Share this post


Link to post
Share on other sites

i have experience with jetting bikes and messing with the needle thanks for the tips i will try it and get back to you

Share this post


Link to post
Share on other sites

Don't run the bike leaner than 40:1. Like everybody esle suggested, jet down a little. My KX always seem to run better with the hotter plug, so you can try that too.

Share this post


Link to post
Share on other sites

try a BR8ES to start with. If it still fouls plugs, try leaning out the needle 1 position. Most of your riding is done in the midrange. Main jet only affects 3/4 throttle and up.

Share this post


Link to post
Share on other sites

papa i forgot to mention in the pm, i moved the main down to 135, and a powernow (I wonder why I forgot about that :cry: hmm probably because it had no effect whatsoever

Share this post


Link to post
Share on other sites

I have an RM100 that has the same spark plug in since March 2004. It's not October and it is still running great.

I find that using the best 2stroke synthetic oil is the cure to long lasting plugs.

I use AMSOIL.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×