Sherco Forum

General Category => Sherco Tech => Topic started by: Majkel on June 10, 2021, 07:45:32 AM

Title: [2020] 300 se factory, no power/stuttering on high rpms
Post by: Majkel 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?
Title: Re: [2020] 300 se factory, no power/stuttering on high rpms
Post by: jamracing on June 10, 2021, 07:51:01 AM
Replace the coil...
Title: Re: [2020] 300 se factory, no power/stuttering on high rpms
Post by: Majkel 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.
Title: Re: [2020] 300 se factory, no power/stuttering on high rpms
Post by: jamracing 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.
Title: Re: [2020] 300 se factory, no power/stuttering on high rpms
Post by: Gartzza on June 16, 2021, 04:05:52 AM
yep, the coil.
Title: Re: [2020] 300 se factory, no power/stuttering on high rpms
Post by: possiblytoofast4you on June 20, 2021, 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