066 decompressor kicking off too soon

[Crofter]

Unless you actually hold it depressed till it starts, you will get kickback. could it be fauty and tripping out just on compression spikes. Top cover has been cracked by snatchback of recoil handle. Viscious saw! Mean saw! Fast saw!

Frank

 

[dstaton]

My 088 did that as well, fixed it with installing the correct RESISTOR Plug!

 

[glens]

... Man's saw.

 

[Crofter]

Originally posted by glens
... Man's saw.

Yah Glen, you got that right. This one seems to have unusually high compression and the timing is certainly not at the late end of production tolerance either. This saw of my sons is the only 066 I have had my hands on so I dont have a good comparison. Just feel that something here is not as intended. My son has bigger hands and can hold the thumb on the decompressor as he is also holding the handle and cranks.
Dstaton; can you tell me more?

Frank

 

[Dadatwins]

My 460 was doing similiar when I got it and I thought the deco. valve was bad. I tried it in another unit and it worked fine. Suspecting the timing, ended up reseting the coil next to the flywheel with a matchbookcover and it corrected the problem.
Before the comments start matchbook kinda real old school but it worked.

 

[Jacob J.]

They also do that when the valve is full of carbon inside, release early and cause a kickback-like response. Usually we replace ours with the plug.

 

[Crofter]

Jacob J; premature release is a good description of the way it acts. I sure would find a functioning decompressor welcome on this saw. It is a bear to get out of the den! I think it needs an inspection anyhow. Didn't know whether it was a common failure mode for Stihl or not. Thanks fellas,

Frank

 

[glens]

Premature release, huh?  Is it a young adolescent saw?  I've heard there are a few good tricks for desensitization, but experience is the best.

Every once in a while I'll give a tug on my 066 without the valve set, but it's usually a total accident.  I'm confident enough in my manhood; I don't need to try to prove it that way.

Glen

 

[rb_in_va]

Originally posted by glens
... Man's saw.

The man's saws don't have the decomp button.

 

[stihltech]

066

Could be the ignition module, some don't kick the timing back at idle the way they should. I found the Elasto start does the trick for me. I don't usually use the compression release.
All I can say is, when you got to start an 066, you need to be serious about it.

 

[rahtreelimbs]

Originally posted by glens
I'm confident enough in my manhood

Glen

Do you change hands???

 

[glens]

How the hell am I supposed to answer that, Rich?  Should I lie or should I lie?

nelG

 

[Crofter]

Glen I have heard Ora Gel works for premature ejaculation. Maybe I will suggest that to my son to try on that little button of a thing that releases the pent up tensions in his 066.
Yah I can start it, but sometimes the terrain is not suitable for my method: put saw on ground, stand on with both feet, pull on cord with both hands! Not really quite that bad, but it is really dangerous to start in the air. I know you are not supposed to do that but it happens.

Frank

 

[Al Smith]

Kick back

I am not familiar with an 066,but on my bigguns,Mac 125 and Homie 2100s,unless you have arms like a weight lifter,you will use the relief.Even so,if not used,it would eventually crack the side cover,from the tension.I spent about 2 hrs ,heliarcing the cover on the Homie,from a non-funtioning valve.

 

[Al Smith]

066 Kick back,full advance?

I just looked at my Stihl micros,about this subject.As been stated before,Stihl recomends the use of 2 plugs,both surpression type,Bosch WSR 6 or NGK BPMR 7A.It seems,that with digital type ignition systems,the proper plug is crucial in the proper operation of the system.By"digital"it means,in so many words,that the cicuitry is counting pulses in relationship to a given time.Although the micros did not state as such,I assume that it uses a hall effect type of sensor crcuitry for this.If the cicuitry is getting a false trigger pulse,perhaps by an improper air gap of the coil[ 8 to 12 thou. ],it would try to go full advance.If this is the case,that powerful 5.6 cu. in. engine would attempt to pull you backwards through the side cover. ugh.If I am incorrect in my analization of the system,would one of you Stihl experts step up to the plate,as I am sure you will.

 

[ccicora]

Just something to try.......
Take the decompression valve and drill out the holes on a press.(Carefully) Then take WD-40 with a wand and blow out the filings.

Later,
Chris

 

[Grande Dog]

I've seen Husqvarna's do this in the past. It's been the detent on the release valve every time. I know they're expensive but, if you have a used one parts stash give it a try.

Grande Dog
Master Mechanic
Discount Arborist Equipment and Tree Care Supplies

 

[Crofter]

I think my son is away on a canoe trip this weekend. This will give him some things to try. Thanks, will let you know what comes of it.

Frank

 

[stihltech]

ignition

Your thoghts on the ignition make sense. Also cheap and easy. Try it.

 

[timberwolf]

carb cleaner and WD-40

Pulled the decompressor off today, looked ok, seemed to click off and on fine, no gross amount of carbon. Also the spark plug was quite new and clean.

So I gave it a shot of carb cleaner and a shot of WD-40, put it back in.... Just Like new!

Still if you yank on it timidly it'l try to wrap you arm back around the fly wheel elasto start or not. Don't know if this is a problem or just a charachteristic , but the saw is certainly managable now without keeping my thumb held on the decompressor.

As long as the saw is not cold or realy warm it seems just as easy to start without the decompressor.