2020 ec 300, jetting help

B737

New member
Hey guys, another jetting thread.
2020 EC 300, STOCK: BR8EG, 42/175, N1EF#2, Slide 7, AS@2
Using Motul 710, 55:1, Temps btw 5-35C/40-90F, Elev: 0-4000F. Float already set at 7mm.
Used this setting when bike new but constantly fouling the plugs.
After reading all the threads in this forum, decided to go with NEDW#3.
Excellent needle but unfortunately, after a technical climb using lots of clutch, even at low revs, the bike just starts to rev up when no throttle applied. It looks to be a lean condition on the low jet.
My main riding style is single track with technical climbs with a lot of clutch and low revs.
Anyone can please recommend another needle for this type of riding style. Thinking also to go higher on the low jet with the NEDW.
Thank you
 
It the engine surging racing high like it's running out of fuel, or just a higher idle than normal? How have you got the bike setup to idle?

Has it blown any coolant while running hot after said climbs? Have you cleaned the pilot out?

The W diameter needle is quite a few steps leaner than an F as above..

First step I would try jumping up a pilot size, or moving the needle one position richer.
 
Its a typical thing, that the idle hangs after doing steep climbs with much throttle.
Provided your pilot circuit is okay, you could also try following.
With engine fully(!) warmed up check how it idles. 9 out of 10 smokers I get into my hands have a too high idle. Set the idle as low as possible, it is acceptable if the engine stalls from time to time.

Once the idle is set as low as possible go riding and try exactly that steep climb and see what it does. If the idle still hangs turn the As in a 1/8 turn and try again. Repeat until the idle hang stops, re-adjust the idle if necessary.

When you are ready and the idle stopped hanging consider your AS setting. If it is less than 1.25 turns you could try the next bigger pilot jet as Jakobi already said.

Don't forget that on most if not all two strokes it takes longer than on 4 strokes till the revs drop down to idle speed. That's a feature ;)
 
Just spared another moment to think about this..

Could be a vacuum leak too. Main seal sucking a little bit, or not getting a good seal between carb and cases. Things to check. Unlikely given low hours and new bike, but something to rule out if you find your jetting is much richer than other peoples.
 
@Jakobi
@Doc Brown
Really appreciate all the help.
Opened the carb and checked the jets and float, all ok. No vacuum leaks as well.
Decided to throw the N1EF during the week, besides a fouling plug after a good amount of hours and the usual feeling with this needle, no problems riding on hills on 1st, 2nd gear. Just a simple test.
Went back to the NEDW#3 with new spark plug. Played with the AS down to 1 turn but not too much change. Idle set as low as possible.
On hill technical climbs at low rpm bike just started to have the high idle with the clutch engaged. OATemperatures are getting higher and the bike just boiled really quick.
Definitely I will increase the pilot jet and clip #4.
I will keep you guys updated.
Thank you
 
@Jakobi
@Doc Brown
Really appreciate all the help.
Opened the carb and checked the jets and float, all ok. No vacuum leaks as well.
Decided to throw the N1EF during the week, besides a fouling plug after a good amount of hours and the usual feeling with this needle, no problems riding on hills on 1st, 2nd gear. Just a simple test.
Went back to the NEDW#3 with new spark plug. Played with the AS down to 1 turn but not too much change. Idle set as low as possible.
On hill technical climbs at low rpm bike just started to have the high idle with the clutch engaged. OATemperatures are getting higher and the bike just boiled really quick.
Definitely I will increase the pilot jet and clip #4.
I will keep you guys updated.
Thank you

Did moving to #4 help at all?
 
Back
Top