Stihl ms661 cutting out at high revs

[samshack1]

Hi guys I was wondering if anyone was having the same issues as me with an ms661  it's a 2018 model.It makes a strange clicking noise and cuts out at high revs constantly. I have reset it and still no change the guy who fixes my tool can't seem to get to the bottom of it. 

Thanks Sam

[Paddy1000111]

Any chance of a video? Does it make a strange clicking noise all the time or just at high revs when it cuts out? 

[samshack1]

Yeah It makes the clicking noise at high revs and then cuts out it really frustrating as I have to use it at half revs it cuts out under any kind of residence too. Cheers

[Paddy1000111]

Does it cut out instantly as in shut off like you hit the off switch or does it bog down and die? 

[samshack1]

Yeah as if the off switch has been hit. Cheers

[Paddy1000111]

Well the clicking to me sounds like it's missing and the fact you  said it cuts out under any kind of resonance sounds to me like you have a wire chafed though causing the ignition system to earth out somewhere and cut out. I'd suggest you make a start by taking off the fan cover and the top cover and get in with a small torch and just look at the wiring and check for any chafing points any loose plugs. Give everything a good tug and wiggle and make sure all the wires are in good nick. Also take the spark plug boot off and have a gander at the spark plug lead end connector as I have seen a few of these snapped. Another thing to look at is the little nipple on the end of the plug, on some models these unscrew, make sure its not come off or loose. If you have another spark plug then pop one in first and check again as the wire inside can crack or the resistor can give out and when it gets hot under full load they can cut out too, it's a similar result the engine misses/pops/clicks and then just dies. You let them cool off and fire it up and it will sit at half RPM/idle all day long as they don't get hot enough to die. 

 

Here's the 661c-m service manual if you want any info on taking stuff off or wiring harness diagrams-

661 c-m.PDF

[samshack1]

That's great I really appreciate your advice I will look into to all these things. I will keep you posted.

Thanks

[spudulike]

Damn, did that fella say "Nipple"??????

[Paddy1000111]

Just now, spudulike said:

Damn, did that fella say "Nipple"??????

Well, I usually grease it up and give it a little twist. Can't think of anything else to call it ?

[spudulike]

Sounds like the correct action. BTW....71 years or 1971?