Author Topic: [2020] 300 se factory, no power/stuttering on high rpms  (Read 142 times)

Majkel

  • Novice
  • *
  • Posts: 10
    • View Profile
[2020] 300 se factory, no power/stuttering on high rpms
« on: June 10, 2021, 07:45:32 AM »
Hello,
Recently my 300 we factory started to loose top end power, it never revs out and instead starts stuttering. It will continue to run (not bogging dead) if I keep holding full throttle but never revs out/kicks. Low/middle works like a charm and no starting or idle issues.
I didn't have any problems before, but noticed last ride that it started to go a little unclean on higher rpms. But it revved after 2-3 seconds with full throttle. Now as meantioned, it cannot rev out at all.

Current jetting: main 172, pilot 40, n8re second clip, 1 1/2t,  running 40m above sea level.

I have checked following:
- Power valve is not stuck.
- No bad cables etc.
- Cleaned carb.
- Tried leaner jetting
- Checked reeds.
- No air leak

I haven't done any electrical measurements.

I start to suspect that the power valve servo is malfunctioned or it might be bad coiling... but maybe someone here have an idea what the problem could be?

jamracing

  • Vet
  • *****
  • Posts: 581
    • View Profile
    • Email
Re: [2020] 300 se factory, no power/stuttering on high rpms
« Reply #1 on: June 10, 2021, 07:51:01 AM »
Replace the coil...
2020 300 SE Factory

Majkel

  • Novice
  • *
  • Posts: 10
    • View Profile
Re: [2020] 300 se factory, no power/stuttering on high rpms
« Reply #2 on: June 10, 2021, 07:58:18 AM »
Ok, thanks for input, I will try that, I was also thinking of that before but felt unsure because it runs ok on lower middle.

jamracing

  • Vet
  • *****
  • Posts: 581
    • View Profile
    • Email
Re: [2020] 300 se factory, no power/stuttering on high rpms
« Reply #3 on: June 12, 2021, 11:01:56 AM »
I had the same situation, ran fine down low and mid, but had starting issues once it was hot. The bad coil still showed proper resistance numbers when cold as well.
2020 300 SE Factory

Gartzza

  • Novice
  • *
  • Posts: 47
    • View Profile
Re: [2020] 300 se factory, no power/stuttering on high rpms
« Reply #4 on: June 16, 2021, 04:05:52 AM »
yep, the coil.

possiblytoofast4you

  • Novice
  • *
  • Posts: 8
    • View Profile
Re: [2020] 300 se factory, no power/stuttering on high rpms
« Reply #5 on: Today at 12:19:24 AM »
Id recommend chasing a better jetting spec, you've got some power left on the table. unless you're riding sand. 

try
40,
n8rf or n8rg(leaner) clip 2
170

Majkel

  • Novice
  • *
  • Posts: 10
    • View Profile
Re: [2020] 300 se factory, no power/stuttering on high rpms
« Reply #6 on: Today at 05:21:28 AM »
I kittet up with some additional jettings, so will try your suggested jetting.
Honestly when looking back, I have not put much attention to the the jetting before buying this bike, but I have learned a lot about this when troubleshooting and searching for info. So thanks for all inputs.
Also I have a new coil now (not fitted yet), so hopefully this will not be a problem when everything is in place.