Clutch spring hack

[AHPP]

23 minutes ago, Dan Maynard said:

Is it possible the trigger mechanism is a little bit sticky? So trigger not quite returning all the way?

 

Doesn't feel like it and the saw generally doesn't do much work so is in good nick. Will check though.

[AHPP]

12 minutes ago, Mark Bolam said:

I would think the tendons in your forearms will soon be a much more important issue.

 

Yeah, I'm not going to do that every day. It's fine on vibes etc though. Impressive machine really. Apart from this monstrously bad running on. And I mean bad. Like quarter throttle easily. Wasted loads of effort dragging the chain to a stop on wood and using the chain brake unnecessarily. Not to mention it's horrendously dangerous if you don't have your wits about you. Where you'd normally gribble through the last inch of cut so the chain has already stopped when it drops into space, you now have to worry about it picking back up to quarter or third throttle. You're effectively stood there with a machine gun that's stuck firing unless you want to abuse the chain brake.

[PaulTem]

On 16/08/2025 at 14:43, AHPP said:

Shaft blind drilled to a cross drilled grease port. Got it. Yes. Good idea. Unless it doesn’t matter. But I’d probably grease a Husky if it’s as easy as that. 

Agree it's a really neat idea.   Will just add that a friend had a crank snap at that point on 2 ocassions, where the chain hadn't been slackened off enough after use and had tightened up too much when contracting as it cooled down... just saying!

[Stubby]

44 minutes ago, PaulTem said:

Agree it's a really neat idea.   Will just add that a friend had a crank snap at that point on 2 ocassions, where the chain hadn't been slackened off enough after use and had tightened up too much when contracting as it cooled down... just saying!

Do you know , I only use Husqvarna saws and I have never had that happen . I do tend to run them slightly on the slack side ( I am not a farmer 🙂) 

[PaulTem]

23 minutes ago, Stubby said:

Do you know , I only use Husqvarna saws and I have never had that happen . I do tend to run them slightly on the slack side ( I am not a farmer 🙂) 

It's really all down to good practice when working and maintaining your gear, isn't it. TBF, I think they must have finished late and not checked everything up properly.

Prefer the Huskys too. Fave is my 357, which is known as the Heinz 3-57 because it was put together from the remnants of around a dozen others!!  

[Stubby]

12 minutes ago, PaulTem said:

It's really all down to good practice when working and maintaining your gear, isn't it. TBF, I think they must have finished late and not checked everything up properly.

Prefer the Huskys too. Fave is my 357, which is known as the Heinz 3-57 because it was put together from the remnants of around a dozen others!!  

I had a ported 357 back in the day . It ran on caster bean oil .  Loved the smell . Today I use Alkylate fuel mixed at 50:1 with Red Line racing 2t oil . Almost as good a smell ! 

[Oldfeller]

4 hours ago, Stubby said:

I had a ported 357 back in the day . It ran on caster bean oil .  Loved the smell . Today I use Alkylate fuel mixed at 50:1 with Red Line racing 2t oil . Almost as good a smell ! 

Huh? that's a laxative Stubby,among other things, but  never heard of being used in a chainsaw.

[Mark_Skyland]

On 23/10/2025 at 20:56, AHPP said:

Still haven't got this sorted. I did 52 tonnes of firewood over two days this week with it and it ran on extremely badly but with no other ill effects. Yesterday it was screaming through ash for 9 hours on a 13" bar. And I don't mean cutting a bit then letting it idle while I walked somewhere. I mean a digger put wood in front of me and I was barely out of the cut for hours on end (bar fuelling). 14 litres of mix. If there was something as fundamentally wrong as an air leak, it would have melted.

 

It was in a pro workshop last week for the cutting out thing (fixed - a bullet connector was loose at a solenoid) and he said he couldn't see anything else wrong with it.

 

I think it's the electronics. Felt a bit like a throttle position sensor playing up because a fractional squeeze on the trigger often slowed it down. Does a 661 have a throttle position sensor?

It does have a throttle position sensor, its called the trigger unit.

 

I think running a 13" bar is causing the problem. It must be constantly running at max rpm's which is likely causing issues with the auto tune. I understand that huskys have an issue if your running a blunt chain as that will also increase the rpm, I presume that its the same with stihl machines.

 

I think you're right about it not having an air leak, what colour is the spark plug?

 

 

 

[AHPP]

58 minutes ago, Mark_Skyland said:

It does have a throttle position sensor, its called the trigger unit.

 

I think running a 13" bar is causing the problem. It must be constantly running at max rpm's which is likely causing issues with the auto tune. I understand that huskys have an issue if your running a blunt chain as that will also increase the rpm, I presume that its the same with stihl machines.

 

I think you're right about it not having an air leak, what colour is the spark plug?

 

 

 

 

Can you explain what you mean about the trigger unit. I'm too stupid to get a joke if it was that.

 

It does it on 20" too and I make sure to not over rev. I let the chain bite and then apply throttle to that bite. Keeps the revs to probably 75%. If you just let it scream at 100%, the teeth skim and it's more noise for less cut.

 

I'll dig through my phone in due course for a plug photo from a heavy 13" or 20" firewood session. Will have a look at the plug itself too. It was doing some fairly gentle felling with 36" on Saturday and got the proper cool down etc. Still ticked round a tiny bit after bigger cuts and it was really very gentle use compared to the firewood. Felt more like normal creep (although the clutch springs are new remember) rather than when it runs on badly, which feels like a throttle thing.

 

I get what you mean about the 13" confusing the autotune but I'd also expect a top brand's top machine to cope with it.

Edited Sunday at 23:03 by AHPP

[Mark_Skyland]

The trigger unit is this 

Trigger Unit for Stihl MS661 C-M, MS661 C-MW Chainsaws - OEM No. 1144 430 1010

WWW.LSENGINEERS.CO.UK

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Overview: The Trigger Unit for Stihl MS661 C-M and MS661 C-MW chainsaws is a genuine Stihl control component that restores precise throttle actuation and dependable response...