Stihl 026 - Pulsating Ignition?

[SteveSr]

Hello,

I have an 026 recently stripped to the crankcase and rebuilt (mostly rubber parts). Went to run the saw and it starts and idles fine. It will accelerate fine at WOT but when it gets to a certain RPM it dies just like the kill switch was engaged. Once the RPMs drop to near idle it will pick up again and the process repeats.

Anybody seen these symptoms before? I can't believe that a carb defect would cause this behavior so am thinking a bad ignition system (coil). Your thoughts?

Thanks,

Steve

 

[RI Chevy]

@drf256

 

[RI Chevy]

My initial thought is maybe a pinched wire. Could be a bad coil too.

 

[paragonbuilder]

Hello,

I have an 026 recently stripped to the crankcase and rebuilt (mostly rubber parts). Went to run the saw and it starts and idles fine. It will accelerate fine at WOT but when it gets to a certain RPM it dies just like the kill switch was engaged. Once the RPMs drop to near idle it will pick up again and the process repeats.

Anybody seen these symptoms before? I can't believe that a carb defect would cause this behavior so am thinking a bad ignition system (coil). Your thoughts?

Thanks,

Steve

Video?

 

[Lone Wolf]

Sounds like the spark is jumping and grounding out somewhere. Check the plug connection and all the wires .

 

[drf256]

Air filter

 

[TJ the Chainsaw Mechanic]

X2 with the air filter.

 

[SteveSr]

Video?

Love to be able to provide a video but need a tutorial on how to get it from the phone to this web site. I don't have video editing software and Imagine that the video file will need to be compressed to make it suitable for the web.

 

[paragonbuilder]

Love to be able to provide a video but need a tutorial on how to get it from the phone to this web site. I don't have video editing software and Imagine that the video file will need to be compressed to make it suitable for the web.

Do you have a YouTube account? Easiest to upload to YouTube and then give a link.
If you don't, text it to me at 8604284598 and I'll post it for you Steve.

 

[stihl_head1982]

 

[Lone Wolf]

 

[dall]

Do you have a YouTube account? Easiest to upload to YouTube and then give a link.
If you don't, text it to me at 8604284598 and I'll post it for you Steve.

can i text you dan lol

 

[RI Chevy]

Ut oh. Lol

 

[SteveSr]

Hello,

I had a chance to take a look at this again today. And the answer is... Drumroll... Air filter! For those of you that had the right answer give yourself some...:cheers:!

All I can say is...:wtf: This is a BRAND NEW Stihl OEM filter. I don't normally look at brand new parts as potential failure items. I started the saw up with the AF cover removed and while it was misbehaving I watched in disbelief as the choke lever moved back and forth... all by itself!

So for those of you that have seen this before did Stihl lay some bad filters with weak springs or make a production change and use the wrong spring? From my dead filter pile I found two variations. One had a limit stop on the choke lever arm which prevented the choke plate from contacting the rear half of the filter while the other one didn't. Both of these seemed to have a stronger spring than the one in my defective filter. Swapping a spring from a dead filter fixed the issue.

Thanks,

Steve