660 Fast idle solution..........hooray!!

[traffic903]

Since assembling my 660 project I, like many others, have had a problem with the fast idle not working as it should. Instead of "locking" in position when moving the master control from choke to fast idle, it would simply slide straight into the normal idle position. I found this very frustrating when starting.

So after trying many different things to solve this problem, and failing miserably, I started scouring the web for an answer. It took forever to find something definite about this, but I did eventually come across a post on Arb....tsite by Wood Doctor. FULL CREDIT FOR THIS SOLUTION GOES TO WOOD DOCTOR. I am just recycling his information and images because due to the photobucket fiasco, they are no longer available (unless you know how to get around the problem ).

I am not sure whether I can post a link to that site or not so I will just post a VERY short summary of his fix.

First you need to make this "shim."

Then you fit this shim in this location........



The shim pushes the left side of the master switch back toward the trigger, and in doing so makes the whole mechanism work correctly. I just made mine up out of some aluminium flat bar. Super simple, works perfectly.

Once again, not my fix, thanks go to Wood Doctor. I hope he doesn't mind me using his images.
Cheers.

 

[traffic903]

Looks like this when fitted........

 

[traffic903]

One more pic....

 

[Mattyo]

i was wondering if a piece went in that spot... tx!

 

[Hinerman]

Since assembling my 660 project I, like many others, have had a problem with the fast idle not working as it should. Instead of "locking" in position when moving the master control from choke to fast idle, it would simply slide straight into the normal idle position. I found this very frustrating when starting.

So after trying many different things to solve this problem, and failing miserably, I started scouring the web for an answer. It took forever to find something definite about this, but I did eventually come across a post on Arb....tsite by Wood Doctor. FULL CREDIT FOR THIS SOLUTION GOES TO WOOD DOCTOR. I am just recycling his information and images because due to the photobucket fiasco, they are no longer available (unless you know how to get around the problem ).

I am not sure whether I can post a link to that site or not so I will just post a VERY short summary of his fix.

First you need to make this "shim."
View attachment 107047
Then you fit this shim in this location........

View attachment 107048

The shim pushes the left side of the master switch back toward the trigger, and in doing so makes the whole mechanism work correctly. I just made mine up out of some aluminium flat bar. Super simple, works perfectly.

Once again, not my fix, thanks go to Wood Doctor. I hope he doesn't mind me using his images.
Cheers.

@Wood Doctor is a member here too

Yes, you can post links to Arboristsite here.

 

[Wood Doctor]

I appreciate the salutation. The shim may eventually wear with friction. I ran into this also and had to replace it. The aftermarket tank housings are a slight improvement but not much. Sometimes the 660s work OK. I have one that does, but I figure it will wear down with time. One thing I found is that bending the throttle rod for a fix is a hopeless endeavor. That's not even worth trying.

I have noticed lots of men cold start the 660 after a choke pop by holding the throttle open with the left hand and pulling with the right, thus giving up completely on the fast idle setting. That's a PITA but it works.

Funny thing, these are the only Stihl saws I have ever run into with this lousy fast idle control problem. All the rest hold their fast idle and work OK.

 

[traffic903]

I appreciate the salutation. The shim may eventually wear with friction. I ran into this also and had to replace it. The aftermarket tank housings are a slight improvement but not much. Sometimes the 660s work OK. I have one that does, but I figure it will wear down with time. One thing I found is that bending the throttle rod for a fix is a hopeless endeavor. That's not even worth trying.

I have noticed lots of men cold start the 660 after a choke pop by holding the throttle open with the left hand and pulling with the right, thus giving up completely on the fast idle setting. That's a PITA but it works.

Funny thing, these are the only Stihl saws I have ever run into with this lousy fast idle control problem. All the rest hold their fast idle and work OK.

G,day Doc.

I was so relieved when I eventually found your solution. I had spent many hours bending, polishing and reshaping things to try and get it to work. Well done on working it out!!

I think I will change the aluminium shim out and fire up the 3d printer and print one in Petg. That will be a lot nicer on the master switch and it is quite hard wearing. Plus if it does wear out I can just print another one.

Again mate, thanks for figuring this out. It's great that you are a member here too.

 

[Mattyo]

if you get a 3d print file that works, maybe you could share it with someone in the states and we can have a bunch made.

i'd definitely would like to have a few on hand, just for the heck of it

 

[MustangMike]

I lube the control shafts with Vaseline, seems to really help. Guess if your worried, just do it every so often.

 

[traffic903]

if you get a 3d print file that works, maybe you could share it with someone in the states and we can have a bunch made.

i'd definitely would like to have a few on hand, just for the heck of it

I will mate. Will be very easy to do one for 3d printing. Stay tuned.

 

[traffic903]

I lube the control shafts with Vaseline, seems to really help. Guess if your worried, just do it every so often.

Yes I tried lube EVERYWHERE but still no joy. This fixed it though.

 

[Wood Doctor]

I lube the control shafts with Vaseline, seems to really help. Guess if your worried, just do it every so often.

I tried lubing the switch control shafts also but to no avail. The problem is in the pressure on the trigger and cam mechanism design. These start to wear down in time and then nothing holds throttle rod in position so that a fast idle is maintained. The shim helps maintain the pressure.

Stihl should have redesigned the entire assembly after the 066, but they failed to do so and passed it on to the 650 and the 660. Even the smallest difference from one production schedule to the next can cause the fast idle to not engage. It's that sensitive. My 660 works very well, but I got another one in today that cannot hold the fast idle.

I guess what irks me the most is that all the other Stihl saws I own do not have this problem. Somebody was asleep at the switch with the 066, 65o, and 660.

 

[MustangMike]

Well thanks for coming up with a solution, I will definitely remember it.

 

[traffic903]

Righto, so for anyone that is interested, here is the STL file of the shim. I have printed it out in PETG and it fits and operates perfectly. I used PETG due to its great strength properties but realistically any filament would probably do. It took all of 4 minutes to print! If I were selling something like this then I would feel bad charging any more than about $5 for it (that's just some information for those that would have to pay for this to be printed - so you don't get ripped off!). Any questions, feel free to hit me up.

Can't upload directly to here due to file type, so here is the link to Thingiverse:
https://www.thingiverse.com/thing:2759693

 

[traffic903]

Shim.

Installed.

 

[traffic903]

Gents I was just thinking...........

How about I print off say 25 or 30 and put them in an international envelope to send to one of you. Then if someone needs one, that person can send one on. It would be a way for me to pay back the help I have been given.

What say you? Who would like the responsibility?

 

[backhoelover]

Who every does the shin please send me 2 and let me know what I owe u

 

[Mattyo]

Maybe send a pile of them to hl supply. ..and they can distribute in future kits. Just a thought

 

[traffic903]

Maybe send a pile of them to hl supply. ..and they can distribute in future kits. Just a thought

No, I don't want people to have to pay for it. Are you in a position to take the role on mate? How much does a letter cost to send in the US. Here it can go anywhere in OZ for $1.10 or so. So if I sent you (or someone else) say 30, then it would cost you the letter price times 30 to send them on. A few "donations" from people would cover that.

 

[jmester]

I will do it. Thank you for your willingness to help out the forum and others.