440EX jetting questions & plug reading?

[Steven]

I took my plug to Honda today for a reading.

I had just made a 5th gear run at WOT, killed the throttle, and pulled the plug.

Running a dynojet 175 main, the guys at Honda took one look and said... "lean."

WTF? This damn thing is so thirsty!

They said the entire plug, including the porcelain should be coffee color. Is this the general concensus on ths board? THe electrode and plug arm are brown but the porcelain is whiteish tan.

Tonight I installed a dynojet 180 main and lowered the clip one on the needle. Hope that does it. Gas mileage is really starting to suffer.

What are you guys running for jetting on your 440's?

Steve

Thats sounds a little bogus to me but hey what do I know.

Most dealers and even mfg's would like you to run a little rich anyway so I dont even think of asking.

K&N and Dyno (which I believe are the same jets) jets are supposed to be the same as the Keihin but I am not convinced of this cause I have had experience's that seem to show there not.

I am currently running a 168main and it seems to be too rich. Was at a 169K&N and it was very lean. I am hitting it in the middle after my current motor work and will see what happens with the 165.

BTW you description of the plug sounded fine. Do you hear any deceleration pops? does it bog? any other problems?

Run the plug a little longer next time and check it again, beige and tan and light brown all look a lot the same depending on who you ask.

Hopefully one of the guys with more jetting experience will chime in

[YZROOSTINYA]

kn/dynojet are differant from the stock jets. the plug sould be tan like a coffee stain. the porcelin should be tan, not white

[bmf400ex]

plug readings aren't the best way to tell if ur lean nowadays. becuase they(oil companies) are putting so much **** in our gasaline these days that the gas burns so much cleaner now its hard to get an accurate reading.
but still, you can get a good idea.
k&n jets are the same thing as Dyno jets, but they are different than Keihin. and i don't know the equivalent, but i do know that dynojet/k&n are smaller than the keihin jets of the same number.


tell me what color was the plug? and was it wet at all or any carbon at all, what, need more info.

[Steven]

Ok, I just made another run after theroughly warming the bike. This time with a 180 dynojet main and the clip on the needle lowered one more level.

The bike ran very well on the pavement. No bogs, no pops, just clean/strong acceleration in all parts of the power band and at all throtle positions.

This time, I made a pass in third gear because I was in my neighborhhod. I started at the bottom of the gear and pined the throttle. A few seconds after the gear wound out, I hit the kill switch.

Ok, now the plug description:

Starting from the outside and working in.

There is a ring of metal on the base of the plug just past the threads. The color is like a blackish soot.

The porcelain is a light tan to ash color with a few small specs of black sooty deposits-not at all coffee looking.

The metal tip at the end of the poecelain is light black to dark brown.

And finally the curved bar at the end of the plug is all a nice coffee brown color.

I am running 100 Octane GT2 Race Gas for these tests, for those taking notes on gas type and its effect on plug color.

The plug type is an NGK-R DPR9Z.

So, what now? Should I try the 185?

Thanks, Steve.