066 enigma

[fdhamlin]

Got a Stihl 066 red light from a retired logger a while back.
It had been setting in the corner of a shed for years.
Too heavy for him and was replaced by an 046.
Cleaned it up and gave it a carb kit. Got it to start after much carb priming.
Now it starts fine lots of compression and idle and revs well.
But when I try to restart it wont turn over. I can get about half a pull and it stops dead.
Set it aside for a while and try another cold start and it starts fine.
Try a warm start and the same thing.
So I put it back in the corner of my shed.

Hoping for ideas, as I have none! Fred

 

[singinwoodwackr]

Got a Stihl 066 red light from a retired logger a while back.
It had been setting in the corner of a shed for years.
Too heavy for him and was replaced by an 046.
Cleaned it up and gave it a carb kit. Got it to start after much carb priming.
Now it starts fine lots of compression and idle and revs well.
But when I try to restart it wont turn over. I can get about half a pull and it stops dead.
Set it aside for a while and try another cold start and it starts fine.
Try a warm start and the same thing.
So I put it back in the corner of my shed.

Hoping for ideas, as I have none! Fred

Pics, vid?

 

[Sloughfoot]

Don't know why it would be doing it but it sounds like vapor lock.

 

[fdhamlin]

Pics, vid?

Not much to show, half a pull and dead stopped.

 

[Sloughfoot]

Not much to show, half a pull and dead stopped.

Do you know if the timing has been advanced?

 

[jacob j.]

Did you pull the top end as a part of your refresh? It sounds like you may have a broken main bearing cage.

 

[fdhamlin]

I did think about bottom end bearings but couldn't find any sign.
Weird that it starts and runs fine cold. Had the jug off, nothing loose
and turns fine. Flywheel key is okay and coil gap is right.
As the story goes, it was running when I shut it off.

 

[qurotro]

RED Light 066 period is almost famous for bad coils. Try another ignition is an easy thing.

 

[Woodpecker]

Send it to @tree monkey for port work and a refresh… MyTM flat top red light/lever 066 is a beast! Would be well worth having Scott work his wizardry on yours.

IMG_6886

Tree Monkey Flat Top 066 with an 8 pin sprocket and 24” bar and chain

vimeo.com

 

[fdhamlin]

Okay, we are way off track already.
Problem is, it starts and runs cold.
When warmed up it won't pull over.

 

[Sloughfoot]

Have you tried to turn it by hand on the flywheel or clutch bolt?

 

[singinwoodwackr]

Okay, we are way off track already.
Problem is, it starts and runs cold.
When warmed up it won't pull over.

Ok, so, somewhere there is a metal part that is expanding and binding when warmed up.
Check coil gap, cold and warm
Check squish, cold and warm
Check all clutch parts for something odd.
Check flywheel for any weird wear spots.
Recoil anomalies?
Bore-scope the cyl from the top as well as through the carb into the bottom.
Or, could be something rattling around in the bottom that only catches at temp.
Either way, I’d be tearing it down completely

 

[pbillyi69]

i would tear it all the way down and figure out what is binding it up before it totally lets loose and destroys itself.

 

[Stump Shot]

I don't know of any shortcuts that will help past a thorough investigation of the issue at hand. However, I would start out and pay particular attention to the PTO clutch side and see if something is awry there before moving on to the rest of the saw.

 

[legdelimber]

Have you removed the spark plug immediately after it locks?
Looking for a wet plug or signs of fuel flooding the saw enough to hydro lock it.
Just for giggles, have you loosened the fuel cap when it's locking up ?

I have an Echo cs-302, metal tank shares a wall with the crankcase.
The Ethanol blended fuel (big city blend) would boil in the tank after running a bit.
It tended to push a little bit of the fuel into the saw sometimes and could be a handful to pull over in hot weather.
If you loosened the cap while it's hot, the E-gas would spew like a shaken soft drink.

 

[hacskaroly]

Got a Stihl 066 red light from a retired logger a while back.
It had been setting in the corner of a shed for years.

Most of the saws I have came from this type of situation or even worst, from the dump. I have found from experience when I get a saw that has been sitting for a while, like years, then that saw gets a full tear down, new bearings, oil seals, gaskets and broken parts repaired or replaced. I found this out with my 046. Found it at the dump, cleaned it up and replaced the fuel tanks (old handle broke off), got it running and went and cut firewood. Ended up with a scored piston/cylinder due to an air leak, most likely an oil seal.

With all of my project saws, I automatically factor in new bearings and oil seals...a good tear down allows me to clean it up really well and look for any other issues the saw may have.

Who knows how long the retired logger ran those bearings and oil seals, due to use and length sitting, I would hazard a guess it is ready for a fresh set.

 

[Stump Shot]

Also, quite easy to pop off the muffler cover and do a quick check of the piston/cylinder condition. I could imagine one with aluminum smearing doing such a thing when heated and then cooled. At any rate, simple enough to do and find out one way or the other.

 

[fdhamlin]

Okay, Thanks to you all for your ideas. I think I'll leave it in the corner 'til next winter.
Meanwhile, I've got a Husky 181 SE if I want a hard pull!

 

[Maintenance Chief]

I had an 066 that would lock up intermittent, nylon cage bearings.

 

[Michael Rupley]

I am a little late to this party but if it was mine, I would turn the ignition off when it was stopping and see if it pulled normally. (why do I have to suggest these common sense things?) Some of the ignition coils go to advance setting when warm. New coil would fix this. Mike