Ec300 not idling when hot.

[enigma-zn]

Hi Guys,
I need some assistance please.
My 2001 ec 300 starts easy hot or cold and idles well when cold, but does not idle at all when hot.
It is a bit hectic when going downhill and she cuts out if throttle is not blipped.
She runs well throughout the range and no bogging observed, only idling problem.
I really like my bike but her cutting out a lot is tiring during a race when kickstarting all the time.
Thanks

 

[Jakobi]

Are you running the stock needle??

Myself and others here have found that a rich needle diameter E F G with a smaller pilot will result in a good response, but will not idle as well. Going to a H W/I J diameter needle with a larger pilot will help get a steady idle while retaining response.

IE 38 N1EF#2 175 may be similar but better than 42 N1EJ#2 175. The leaner needle diameter will also assist to clean up the 1/8th throttle burbles.

Is the idle adjustment screw wound right in??

 

[enigma-zn]

Hi Jacobi,
yes , idle screw is turned right in.
pilot is 40
main jet is 175
needle is N1EF
Will check needle position and take your advice and try different needles.
Will also strip and check reeds.
Thanks for your reply
I used to race the Hare scramble series on my Honda 250x but changed to the Gasgas as i really like the handling and power but my laptime was longer due to stalling and kick starting a lot,which i found very tireing at my age.
Will let you know what i found.
Thanks.

 

[Jakobi]

Just a little more to help clarify..

By having the idle adjustment screw wound in so far you have essentially cut the pilot/needle diameter out of the equation which is why you have the inconsistant idle.

The 40 and the F diameter are too rich so you are forced to lift the slide to the point that things lean out enough to idle. The result is that you end up on the needle taper.

If you go to a leaner needle you can then back the idle screw off and the air screw will then have a greater effect aswell.

My personal experience is that the following pairs idle well for me.
38 - H diameter
40 - I/W diameter
42 - J diameter

Their are several needles available which will alter the deliver and characteristics of the engine which I will describe. Some are twin taper and others triples which will alter the size of the main jet required.

N1Ex/NOZx (triple) - Stock, how you are now.
N3Ex/N3Cx (twin) - rich to lean, smooth bottom with an aggressive mid range hit. Requires a larger main to compensate for lean second taper.
NEDx/NECx (triple) - lean to rich, easy to get the bottom end clean (no burbles) without having an angry mid hit. Linear power.

The second naming I have put after the original indicates the same taper with a half clip difference.

 

[Bryan]

My 2001 had the same issues. I went through it and cleaned the carb, checked the float level (which was not set right) and repacked the muffler. I think it was a combination of the three that cleaned it up. Now it will start easy, idle hot or cold and is much snappier. It used to foul the plug almost every ride. No I can go 4 or 5 rides before I foul a plug.

 

[gasser]

It used to foul the plug almost every ride. No I can go 4 or 5 rides before I foul a plug.

Hard to imagine any gasser ever fouling a plug but it can happen on the 300s if you run an oil with too high a flash point. Use oils that have a flash point under 220-240 degrees Fahrenheit and the fouling should stop if the jetting is anywhere close. I use Amsoil Dominator and Interceptor oils - both have a flash point under 200.

 

[Bryan]

I run Bel-Ray MC-1 at 40:1, not sure what the flash point is. Jetting is very close without getting too lean.

 

[Jakobi]

I run Bel-Ray MC-1 at 40:1, not sure what the flash point is. Jetting is very close without getting too lean.

Obviously rich somewhere if you're fouling plugs.. Just sayin..

I've got over 4500kms on my EC300 from new without ever fouling a plug. I've had them load up when being really rich on the needle but never to the point that I couldn't clear it out.

 

[wasp4banger]

Obviously rich somewhere if you're fouling plugs.. Just sayin..

I've got over 4500kms on my EC300 from new without ever fouling a plug. I've had them load up when being really rich on the needle but never to the point that I couldn't clear it out.

+1 on the rich side. my 300 hasn't fouled a plug in the last 4 years.