what would you do?
 

just after opinions?

firstly bike currently has 42 pilot, JD Blue needle on top clip, main 180 A/S about 1 1/2 out

bike has recently come back from a bottom end build, on first ride out it fouled a plug, just put new plug in and I reckon just by revving seems a little rich, spooge and sometimes hard to rev like to much fuel in there, My problem is, I have a race at the weekend and no chance to ride at all before it, I know the bike is running a bit rich but I know its rideable, I would like to try going down a jet on the pilot circuit but wouldn't be able to test it before the race!

so its no where near ideal but would you a) leave it as is and carry 2 extra plugs in back pack or b) take a chance and put a 40 pilot in and hope for the best, Ive also got a N3eg needle and jd red needle but again this seems very pot luck as to what I would get with no testing,

Any guesses welcome!:D

How did it run before the rebuild? And how was it set up? I wouldn't expect it to change that much, so I would go for a setup that ran OK before the rebuild if possible.

well that's a tricky one as I had been messing with jetting thinking that was the problem with performance for a fair while. that was also in the autumn temps about 15 degress C and now its around freezing. when I took it apart I found it had the not well liked n1ef in clip 4! when I put the JD in I had it in clip 2 but I see today its come back with it in clip one, I think I might just have to go with it as it is and then try and arrange a day when I can just concentrate on the jetting and nothing else

Well, yes, then it's not so easy.
In my experience, the jetting difference between summer (20C) and winter (-10C) is small. I rarely change anything for the winter, but I run a Lectron.
What i would do in your case is depending on the type of race. You rarely foul a plug if you are able to keep the revs up and it's not too gnarly. Bring a spare plug with you. I would consider using a hotter plug, I run my bikes on NGK 7 plugs (BP7ES or similar). I guess your manual says to use a 8 plug? (depending on engine size).
If the track is tight and you rarely open the throttle, I would perhaps chance on going down on the pilot jet.

thanks for that, it is a bit of a gnarly technical forest event but does have fire roads in places that I could open her up and clear her out, also just make sure I use a lower gear and pop the extra plug in my pack, I normally use br8g (or eg cant remember) ive just popped in the iridium equivilant 8 IX.
still head scratching

It would be helpful if you included the year and model of your bike.

yes it would wouldn't it!

2006 ec 250!

So you are not too far off from my year. Here is what I am running:

Bike year & model = 2004 DE250
Temperature (degF) = 35 - 50 degF
Elevation (feet) = Sea level to 1000 ft
Main jet = 178
Pilot jet = 48
Needle & notch = LTR -0 #4
Air screw setting = 2-2.5 turns out
Throttle valve/slide = #7


I'm not sure how the JD Blue compares to the LTR needle.

Here is a guy running a JD Blue:

Bike year & model = 2003 EC250
Temperature (degF) = 50-85
Elevation (feet) = 800ish
Main jet = 182
Pilot jet = 40
Needle & notch = JD Blue, 1 down from top (#4?)
Air screw setting = 2-1/2
Throttle valve/slide = #5

Results:
Runs clean all through range, doesn't have a big hit, just lots of good clean power. Idle is a little rough, depending on temp.

Question is what does your gut tell you in the absence of going through all the plug chop testing? Where do you feel that is is too rich?

Read through here -> http://www.gasgasrider.org/forum/showthread.php?t=2162 for additional ideas

The problem you describe doesn't sound like a pilot jet at all. When you say it seems rich when revving, are you just whacking the throttle open sitting still or are you riding? Does it idle ok? How does it run at 1/4 to 1/2 throttle?

If the bike is idling ok with the AS set at 1.5 then your pilot jet is fine


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