Re: Stihl fs66 strimmer

[Earlybird112]

Hi  latest problem! Hoping someone has some knowledge on stihl throttle trigger springs. I've changed from double handle to single and the second hand throttle had the return spring unattached and I can't see where it connects to the orange trigger piece. The spring lays flat over the on off switch and is secured in place with about an inch of straight tail. If anyone's dismantled one it's probably straight forward but parts diagrams don't show how they all connect unfortunately. Not sure if I can attach photos that may help?

[Mick]

I've repaired loads of them, but have to say it's a real job to explain exactly where things go in writing.  But we'll have a go.  Some pics would be really handy actually, if you could attach one or two to a reply it would be great.

Click the "Attachments and other options " link below when posting, you'll see a browse button to upload your images.

[Earlybird112]

Thanks . I'll add some photos now and see how they look.

[Earlybird112]

I seem to have messed this up a little so may need to do each pic individually.  Sorry to make this long winded.
The orange throttle trigger is pictured with the side that faces down . Once the peg is located in the handle hole it's pretty tight against the spring and switch. I highlighted In red a 2mm raised piece moulded into the switch . Maybe the spring sits against this but there was no sign of wear and the spring in this position will move about a bit with the constant back and forth with the trigger. I can't see anywhere else obvious for it to locate tho

[Earlybird112]

This photo shows the trigger removed and position of spring in the handle ...

[Earlybird112]

This shows the trigger back in position but without the spring underneath tensioned in any way beneath
Stihl seem to make very neat machines the wires and cables are routed nicely and the handle clamps are brilliant.  I must be overlooking something here with the trigger and spring surely !
If i buy another 2nd hand one chances are the spring will be detached once the handle is separated so probably wouldn't be any better off. Hope pictures are clear and I look forward to any replies . Thanks

[Earlybird112]

In position

[Mick]

Still finding it difficult to explain how and where things go from those pics.  I'll see if I've got one of those control housings at work, and try and work something out. 

[Earlybird112]

Thanks I appreciate your help on this . I've had another look and bent the spring nice and flat but it still works it s way off the trigger once you put everything back together. It's basically laying on top of the on off switch which seems kinda weird to me also.

[Mick]

Thanks I appreciate your help on this . I've had another look and bent the spring nice and flat but it still works it s way off the trigger once you put everything back together. It's basically laying on top of the on off switch which seems kinda weird to me also.

Well trying to find one at work didn't go well they've just had a clear out, and what got thrown out, yes, one of those control units complete with drive tube.  Ok so we'll have to think of some other way to resolve this.

That spring you mentioned.  Pretty sure it (or one of them) should actually link to the stop button to flick it off of fast idle when you squeeze the trigger.   When you set it to the start position it would lock the throttle open slightly, and once started you'd squeeze the trigger to release the trigger back to idle.  Pushing the switch fully the other way would turn engine off.

[Earlybird112]

Thankyou for your help so far I'll take a look and report back after Christmas. I think you're on the right lines here so you've definitely pointed me in the right direction. The double handed switch etc I'm replacing has 2 springs so maybe mine is missing one for starters and it has a slightly different set up but essentially does what you describe. May be worth buying another 2nd hand unit and keeping my fingers crossed.!