YZ125 Spark Plug Fouling

[eagles22793]

I have a 1996 YZ125 dirt bike and it keeps fouling plugs around 3 hours on the bike. It used to fouls plugs like every 30 mins but I moved the clip on the jet needle up and now it only fouls plugs about every 3 hours of riding. The plug is not that black I am working on leaning the bike out for the summer. Can anyone give me an idea on what to do so I can ride this summer with no problem?

 

[sharky243]

How much oil are you mixing into your fuel ? What are you gaping the plug at ? Does it smoke alot ? What jetting are you using ?

 

[eagles22793]

32:1 oil mixture I am just buying the BR9EG NGK park plugs it smokes like a 2 stroke; it smokes like my other 2 stroke and it runs perfect. The jets are 350 main and 48 pilot I know the main is right but I am pretty sure that the pilot is a 48.

 

[rmc_olderthandirt]

to start with I would switch to a hotter plug, a BR8EG or BR7EG. That alone might solve your problem.

The next thing I would do is work on the jetting. You can buy a JD jet kit for that bike. A tad expensive but everyone I have talked to who has used JD has been happy with them. Check out www.jdjetting.com

Rod

 

[tcarney9]

I have a 1996 cr 125 that has the same problem. it fouls plugs every half hour. we moved the needle position up a notch or two and it didnt foul a plug for a month or more then started foulong again. we still have no idea what the problem is and we have taken it to many places.

 

[Jesel]

I had that problem with my yz. The plug would be a nice brown color (not perfect, but I like to stay a little on the safe side) and it would foul every other time I rode. I switched to a br9eix plug and it's been in there for 2 years now. It's a little more expensive but worth it.

 

[jsantapau]

the top of this forum page has a thread marked "Jetting links" try reading whats readily available before any rash decisions or ideas one of my favorite threads is
http://www.dirtrider.net/forums3/showthread.php?t=48348&highlight=plug+reading

 

[DLHamblin]

I have a 1996 YZ125 dirt bike and it keeps fouling plugs around 3 hours on the bike. It used to fouls plugs like every 30 mins but I moved the clip on the jet needle up and now it only fouls plugs about every 3 hours of riding. The plug is not that black I am working on leaning the bike out for the summer. Can anyone give me an idea on what to do so I can ride this summer with no problem?

Being a 1996, when was the last top end done? A worn out top end can cause fouling (which no jetting changes will help).

If its in good shape then I agree with trying a one step hotter plug and see how it runs with it.