Take a look at my plug... jetting look good?

[b-b00gie]

Well I havent ridden my bike (99 KX125) yet this year but I'm finally going riding this week. Back in October/November I made some changes to my jetting after getting a PC pipe/can.

The stock jetting is:

Main: 158
Pilot: 45
Clip: 3rd
Airscrew: 1.5 turns out


I experimented with a 50 pilot and the 2nd clip position, but ended up putting it back to stock, but changin the main to 152.

Current setup is:

Main: 152
Pilot: 45
Clip: 3rd
Airscrew: 2 turns out
Needle: stock



The bike seems to run well (with the exception that it sometimes is hard to start) and definately makes more power than stock. However, I'm not sure its running "best".

I know it matters more how it rides than its behavior at idle, but for example. If I fire it up and let it idle, when I crack the throttle all the way, sometimes it bogs. Then when I let go of the throttle, it will let out this big puff of white smoke once the throttle drops all the way back down to idle. If I do it fast enough, it will sometimes stall.


Maybe its irrelavant since its at idle. When riding the bike it feels responsive. I never crack the throttle all the way (cause it'll loop out on me) in the manner I just described when it's idling.


Here are two pics of my plug (br9ev-x which is stock). It appears to be optimal going by Eric Gorr's website. The first couple threads are black and the center is "mocha" brown.

 

[b-b00gie]

Just to clarify, when I said its sometimes hard to start... it's only when cold. Once its running, if it dies or I kill it, it will fire up on the first kick.


Also, I have never wet-fouled a plug.

 

[b-b00gie]

anybody? :think:

 

[Rich Rohrich]

You might want to take a look at this thread. I think it will answer a few questions.

http://dirtrider.net/forums3/showthread.php?s=&threadid=48348

 

[b-b00gie]

Originally posted by Rich Rohrich
You might want to take a look at this thread. I think it will answer a few questions.

http://dirtrider.net/forums3/showthread.php?s=&threadid=48348

Rich,

Thanks for the link... Once I get home I'll chop up that plug w/ the hacksaw to get a better look. I'll post the pics for your opinion as well.


What do you think about the comments I made above above about chopping the throttle at idle? Is it irrelavent?

I know it matters more how it rides than its behavior at idle, but for example. If I fire it up and let it idle, when I crack the throttle all the way, sometimes it bogs. Then when I let go of the throttle, it will let out this big puff of white smoke once the throttle drops all the way back down to idle. If I do it fast enough, it will sometimes stall.

 

[Rich Rohrich]

Without a load on the engine it doesn't mean much. If you jet it properly under a load it will tend to behave under no load.

 

[b-b00gie]

OK, well I chopped the plug and I'll be damned if my batteries in my digicam didnt die...


The color looks exactly like this plug. The color, black carbon ring size and color change from the tip to the ring all look exactly the same. Only difference is mine is silky smooth.

The plug is a br9evx... should I go to an 8?

The main is a 152, one step leaner or leave it?

 

[Rich Rohrich]

Originally posted by b-b00gie
The plug is a br9evx... should I go to an 8?

You should at least test with it because it sounds like the 9 is too cold for your application.

 

[kawakx125]

is there any way to find out if the main jet is correct other than a plug chop, because i dont know of anywhere i could do one at.

 

[cr25096er]

you could ride it and see how it feels then if you think it could be better install a richer one untill you find a point you start to know you were right.