My bike is a pig. It eats gas and spark plugs.

[kshackle]

ust a thought...  I have a 99 KX250, the specs call for a BR8ES plug, you are running a 9.  The plug may not be hot enough.  Depending on the riding I'm planning, I will run either an eight or a seven.  If I'm heading to the track, I run an eight.  If I'm out with a bunch of guys on their 4 wheelers, and will be slow wood/trails, I'll run a seven.  I've had the bike to almost 2 years now, and only fouled 2 plugs.  (both times I forgot to switch to a seven before hitting the trails.)

My bike is still running a little rich, I need to drop one notch on the clip, but I've been lazy and haven't gotten to it yet.  After I change the jetting, I'll probably stay with the BR8ES plug.

Good point on the plug....I use a BR7ES since my riding is typically slow on the trails....my bike runs perfect and I do not foul plugs.

[gowen]

Use the EIX plugs. Even with a bike horribly jetted it usally lasts a season.

[BLAZE]

ust a thought...  I have a 99 KX250, the specs call for a BR8ES plug, you are running a 9.  The plug may not be hot enough.  Depending on the riding I'm planning, I will run either an eight or a seven.  If I'm heading to the track, I run an eight.  If I'm out with a bunch of guys on their 4 wheelers, and will be slow wood/trails, I'll run a seven.  I've had the bike to almost 2 years now, and only fouled 2 plugs.  (both times I forgot to switch to a seven before hitting the trails.)

My bike is still running a little rich, I need to drop one notch on the clip, but I've been lazy and haven't gotten to it yet.  After I change the jetting, I'll probably stay with the BR8ES plug.

Just a quick qustion....Are you saying that the BR7ES is hotter than the BR8ES?

[eprovenzano]

Yes the BR7ES is hotter then a BR8ES.  The lower the number, the hotter the plug.

The bike was designed to run on the 8, but depending on riding type, I'll switch between an BR7ES and an BR8ES, but usually run a BR7ES.

[Arigato]

Since I run mine is sand, I'm running a B9.  Non-resistor, If you have a pace-maker, stand back!

[eprovenzano]

Posted on: August 21, 2006, 12:39:11 PMPosted by: Arigato 
Insert Quote Since I run mine is sand, I'm running a B9.  Non-resistor, If you have a pace-maker, stand back!

As Arigato pointed out, depending on riding style you may need to adjust how hot of a plug you run.  He's in the dessert WFO running a 9.  If I'm running a track I run an 8 (because I'm too old and slow to keep the throttle pinned), but if I'm in the woods busting trails, I'll drop to a 7.  My jetting is a little rich, (because that's how I like it) but I've only fouled 1 plug in 2 years.  Another problem can be your pre-mix.  Find a pre-mix brand you like, and stick with it.  Switching brands can wreck havoc on jetting.  Jet properly, and have fun.

[FuriouSly]

Get the float set first.  A little fuel spilling out when leaning the bike over a bit is OK.  Most racers have the float set to give a little more fuel in the bowl than stock, more supply for wide open throttle (WOT) and when laying the bike over heavy in turns.  Some even purchase a bigger aftermarket bowl or mod the stock one for modified motors using lots of fuel.

Put in a BR8E(G)(medium duty-fine wire nickle) or BR8E(V)(race duty-fine wire gold platinum),  instead of an BR9E(S)(standard duty-copper core).  This will give you a better quality plug to work with and less fowling with longer duty life.  The lower number is hotter and larger number is cooler.  Dunes 9, track 8, woods 7, so to speak.

Then start working on the jetting.  The airscrew really only helps the pilot system (idle to 1/8 throttle) and up to 1/4 throttle where you are just getting on the needle.  So see where your main jet is at first (WOT running good with throttle chop and a plug check) and work back the two steps (needle clip and pilot jet-air screw).  Of course this is a quick overview of the steps.  Start at the top.

Sly