Bottom end

[GreenPeace]

Climbing first gear up a steep rocky hill way under the power band WOT will you feel the effect in power when playing around with the pilot jet? ( quite a mouth full )
If so, will a lean or rich pilot jet give best performance.

 

[canyncarvr]

You'll feel the difference when TUNING for that jet...with the air screw.

Lean or rich best?

Neither. Howzabout 'correct'?

Rule of thumb (not always the rule, of course)..If you're under 1/2 out on the AS, you need a richer pilot. If you're out more than 2 1/2, you need a leaner pilot.

The AS is tuned by throttle response. 2nd gear, slow walk speed, under load...NO lag or burble with a quick flick from off-idle to 1/2 throttle or so. Adjust in small increments (no more than 1/8 at a time) and allow a bit of time for things to 'normal' up after an adjustment.

Just do it and pay attention to the seat of your pants.

 

[Jim Crenca]

As usual, I agree mith CC; however my bike (while having similar mods) does respond a little differently:

* Air Screw not nearly as responsive to minor changes (much to my dismay)
* Needle selection and clip position is hugely important
* Spend time on jetting; it always seems to be worth it (when considering the amount of "good timeO on bike vs. set up time

Initail post was confusing "way under power, WOT?"

For specific advice, give specific conditions ie. mods, temperature, altitude, jetting, gearing, riding ability, etc. :aj:

 

[GreenPeace]

Initail post was confusing "way under power, WOT?"
Meaning I was riding below the power band with throttle fully opened.

Canyncarvr, thanks for the reply. One thing I dont understand. What effect does the pilot jet or AS have at WOT?
According to my knowledge ( picked up at JustKDX site ) the slide is fully opended at that stage so the air flow is at max. The small amount of air controlled by the AS is nothing compared to the amount of air flowing directly through the carb.
The same can be said about the main jet fully opened at WOT comparing to the small amount of fuel going through the pilot jet.

In the mean time I will try the "seat of your pants" tip.

 

[canyncarvr]

A misinterpretation on my part, it seems.

Consider: First gear, steep, rocky, way under power band, wot. And you asked about the pilot jet.

I took that to mean a TRANSITION to WOT, or the effect when you give it a quick flick TO wide open throttle.

I can't imagine your situation. If you're WOT in first gear on a steep rocky section, you should be in 2nd gear already (maybe you'd already been there and the bike couldn't PULL 2nd gear?). You'd have to be getting either wheel-spin like crazy or in a couple milliseconds you'd be snapping the rear fender off after you had looped it.

If you're WOT in first gear and the bike is NOT rev'd to it's maximum, I don't know why you'd be HOLDING it that way. Clutch fanning would have already been happening.

If it's NOT a transiton, but HOLDING it wide open, then you are correct. Pilot jet is out of the picture at that point. It's going to be the main jet that is the fuel metering device.

 

[David Trustrum]

Man I need to go for a ride. Just the description, wheels spinning etc has me dreaming. Too much time on the Trials bike & not enough on kdx.

Either way one of the confusing stumbling blocks is; you must think of the jetting as throttle position in relation to those jets. Not engine revs.

The only grey area, is the transition can load the bike up. Otherwise your understanding sounds spot on.

From the site I assume you picked up all the babble on suggested jetting starting point & checking that the powervalve is not broken which is common but easy to fix.

Along with somewhere near the correct jetting & a decarb (+repack muffler) it makes a heck of a difference.

 

[GreenPeace]

I understand now. The pilot jet & AS has a big influence on the transition to WOT.
Dropping to first gear ( 2nd couldnt pull ) in a steep rocky hill without clutch fanning the bike stalls with WOT. It pulls better whent throttle is 1/4 way open. Thats where pilot & AS is critical.
But I must admit, by that time clutch fanning must have already been taken place.

Thanks for the replys

 

[canyncarvr]

Babble?

I resemble that remark!

 

[David Trustrum]

I meant babble from the JustKDX site, not the forum, but if I have in anyway offended or insulted then it was indeed meant that way, or possibly in a previously unconsidered more offensive way. ;)

Happy NY mate.