Jetting Database - PLEASE ADD YOUR SETTINGS

[GG27]

Originally Posted by ECRider

Thanks guys for your responses.
It appears that the squish head mod & advanced port timing (raised deck 1.2mm) I had done recently has actually made the bike run leaner so I changed from the LTR needle (marked DDK but with dual taper) to CEK needle at #2 clip, 180MJ & 42 PJ & it has cleaned it up pretty well.
It still runs a bit rich at idle to quarter throttle ie air screw still doesn't work. I'll next try a Honda needle R1370DKA (equivalent to a CCL) with larger diameter to get it leaner on the bottom. I was looking at going to a #8 slide however I have been told by a local Keihin dealer that needle dia has the same effect at less $$.

After I did my port matching and tightened the squish I also got a leaner running bike and had some pinging when going up slopes at wide open when I had the ignition on the rain mode, so I kept the switch on the sunny mode and raised the needle half a notch and the pinging went away. I already had a #8 slide so I dropped it in and the off idle response was excellent. I think the slide only afects the of idle to 1/4 throttle response, while the needle afects all the throttle range. I also changed to a richer CCK middle clip needle and the bike has more low end torque, rips right through with descent smooth power with lots of overrev, nice motor now. The air screw had to come down to 1 turn out (from 2 with the #7 slide).

I currently have put in the N1EF #3 with 42 pj and 180 mj with the #8 slide and the bike is as powerful as my previous YZ250 but has a hole just as the PV starts to open,(too rich) so I'll change the main to a 175 to see the difference. BTW weather here is around mid 30s C with high relative humidity for Greece (60%)

[ECRider]

GG27 be careful when leaning off main jet.
I just blew a hole in my piston with the following 42PJ, JD blue #2, 172MJ, 8 Slide. I was doing 125 km/hr on a transport section at an enduro last month, backed off slightly on the throttle, when to power on again & PHUUT! - end of ride .
The bike was running like an animal before hand & was too much in the rocks & logs so I was mostly running in the rain mode although not when she blew. It was pinging a bit during the event but plug checks looked to be OK (not white) & had a similar "hole" as you had described just before letting rip - possibly lean in hindsight.

Lesson I learnt from this - take plenty of time to check new jetting in an area similar to what you'll be racing in & don't always trust what other riders have posted for jetting on their bikes as motor set-up, fuel, location can make a big difference.

Have now just rebuilt the motor & will be going back to something more easily controlled in the rocks & logs ie 42PJ, CEK #4, 180MJ, #8 slide.

[reiterrider]

Here are my first settings:
Bike year & model = 2003 EC-250
Temperature (degF) =32f - 85f
Elevation (feet) =0-3500
Main jet = 175
Pilot jet =40
Needle & notch = EG 3rd clip
Air screw setting = 2
Throttle valve/slide = #6

This was my first two stroke and I purchased in January of 2009. I have a solid 6 months of riding with 3-4 rides a month and 2-6 hours of riding each ride. I would say the bike worked great and had no issues with being too lean or too fat. The plug was a latte color and it always started on the 2nd or 3rd kick.
The power was perfectly linear, but fairly slow off the line. That's why I think this is a good setting for someone new to two strokes or dirt biking. It's been a great transition bike from my Honda CRF 250-X
In warmer weather it seemed to idle a bit high, but was fixed with a half turn of the air screw.

[reiterrider]

Here are my new settings:
Bike year & model = 2003 EC-250
Temperature (degF) =50f - 85f
Elevation (feet) =0-3500
Main jet = 175
Pilot jet =42
Needle & notch = DDK 3rd clip
Air screw setting = 2
Throttle valve/slide = #6

Installed new Power valve cover from Gofasters.com

This is my second set up for my bike
I purchased the bike in January of 2009. I have a solid 7 months of riding with 3-4 rides a month and 2-6 hours of riding each ride.
I went from a 40 pilot to a 42 and a EG needle to a DDK.
Can you say transformational?
This changed the bike in several ways:
It wheelies without hardly trying, yet it's very controllable.
It's still super linear, but has throttle when you need it.
When I'm in tight gnarly stuff, it keeps the front end light. So instead of pushing through the rough terrain, it floats over it creating a smoother ride.

Thanks to Les from LTRracing.com and thanks to GoFasters.com for setting me up with the parts!

[GG27]

Thanks ECRider.
I went back to my original setting of CCK #3 42PJ, 180MJ and #8 slide. This worked really well in an extreme rocky enduro with lots of uphill rock crossings. It was just a wee bit lean when doing transfer sections (made knocking sounds when closing the throttle after keeping the throttle pined for over one minute) and engine boiled over for the first time! O.K. it was 36 Celcius! and only 1st and 2nd gear for over 30 minutes.
So I guess I will raise the needle by half a clip. I also tried CCK #2 with a #7 slide but was a bit too rich of the bottom for my style of riding even if the air screw was 2 1/2 out.
BTW I will never go lower than a 178 main on the 250's.

[moto9]

09 EC 300
2500 elv

172 mj
38 pj
cck @3
a/s 1.0 out

Good off the bottom, I still need to do some plug chops to check the top end

[bondo]

General jetting guidelines for 2-stroke motors at elevation 8000 - 13000 ft.
Pilot: One step richer than stock.
Needle: Clip in top notch (drop needle).
Main Jet: Five steps leaner than stock.

This guideline is the one suggested by Sunsports in Gunnison, CO.

It has been used for many years on a wide variety of bikes.
Obviuosly, the jetting changes outlined pre-suppose a properly jetted bike at or near sea level.

Our application is an '08 DE 300. Specific jetting below.

Stock Main: #178. Re-jetted for Altitude: #165.
Needle: Clip in center notch. Re-jetted for Altitude; Clip in top notch.
Stock Pilot: #45. Re-jetted for Altitude: # 48.

These guidelines and settings have been used at the noted altitude with excellent results.

[300XCRider]

Updated Settings:

2009 EC 300

Ele: 0 - 1500ft ASL
Pilot: 40
Main: 180
Needle: JD Red, 3rd clip position
AS: 1 1/2 out (tested @ 70*, will have to do some fine tuning here I suspect)
Mixture: Castrol TTS @ 50:1

Removed reed block spacer.

Very little spooge and plug chops reveal a good color.

[SideshowBob]

Originally Posted by 300XCRider

2009 EC 300

Ele: 0 - 1500ft ASL
Pilot: 42
Main: 180
Needle: JD Blue, clip in 3rd position
AS: 1 1/2 out
Mixture: Red Line Racing oil @ 70:1

just broke the bike in with these settings. Will report back after Sundays' 50 miler with any changes. But it seems pretty good as it is.

70:1? Holy crap I thought I was risking it at 40:1

[300XCRider]

They guy who did the prep on my bike said he mixes his at 100:1 and has not had any issues. An entire National Enduro season was ran at that ratio.

FWIW, I ran my KTM300 at 70:1 and after 80+ hours, no problems.