066 rebuild no start

ruel

TreeHouser
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Jan 27, 2015
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Harpswell, Maine
I've had an old 066 kicking around for a while not running. Last fall I put a new piston/ cylinder in it and got it to catch for a bit. After a min of running it sputtered out.

Replaced the air filter, spark plug, carb, intake boot and impulse line today, but it won't catch now. Can you saw folks give me a beginner idiots troubleshooting checklist?

Im frustrated cause it did start a few times, I set the carb adjustments to 1 turn out on all 3 needles, electrical thingy is set as close to the flywheel magnet as i could get it

Just trying to get a cheapo saw for milling, not needed for work, so I'm happy to keep tinkering
 
I think stock needle settings are 3/4H and 1/4L. It might need a new ignition. Make sure the flywheel key on the shaft isn't broken. The ignition can be set with a business card between it and the magnet.

Maybe junk recently moved into the carb?
 
First Check spark , IF good then put some mix in a squirt /spray bottle and squirt some mix into carb throat ( a little dab will do ) with the master control lever set to cold start ... See if it will “pop” and get back to us
 
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  • #5
One of my favourite saws. Why did it need the original repair?

Have you vacuum and pressure tested it?

I this saw was used for milling, the old piston/ jug were pretty scored. Overheating from clogged air filter is the story I heard.

Got spark, will try the spray tomorrow.

I got this saw for the learning opportunity. I appreciate the ultra beginners pointers.
 
Well ‘cording to @Nutball STIHLS have no torque so feel free to send to Frankie here in the city with no pity ... here’s the 066s younger sibling ... hotwoods ported 064 thru some cherry ... seems like plenty of torque to my eyes 😂
 
Where did I say they have NO torque? I said they have LITTLE torque, and my context was obviously about how they come from the factory. Besides, WE can't see how big of wood you just cut there, and that looks like only a 25" bar, 28" at best.

And I measured proportions in the video against mine with a 32", and 25" (24") came up closest. I was at least expecting a 28", but the margin of error seemed too small for a 28 to be very likely.
 
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That means??? So I guess it's a fuel delivery issue. Impulse line loose? Faulty carb?
 
It is possible for spark to be intermittent, just saying. Things like the spark wire, the spring on the end could be broken or dirty, plug could have a loose threaded type connector, timing circuit in the coil could be bad.

You could try to see how much you can run it on spray. Maybe put a few drops of oil in the carb to keep things lubed, close the needles, then a little squirt of starting fluid, if it fires be ready to give it pulses of starting fluid to keep it running, try to reach full throttle to ensure the ignition system is all good, then move on to the carb tuning.
 
I've read starting fluid isn't really good on these things. Even with a bit of oil in the carb, I'd be reluctant to use it. If *I* were to try something, I'd put some mix in a bottle, clamp the saw somehow(vice?) to free up an arm(or get someone to help), and pull it over while spraying mix in.
 
They supposedly add lubricants to starting fluid, but a few drops of oil in the carb actually goes a long way. All he needs is 10 seconds of running, just enough to get it up to speed long enough to know the ignition is stable.
 
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  • #18
Ok, got it started and running. Racing engine at 3/4h 1/4L. Adjusted low setting out to 1 or 1&1/4, engine sounded happier but clutch was constantly spinning.

Air leak? Replace crank oil seals to start?
 
Ok, got it started and running. Racing engine at 3/4h 1/4L. Adjusted low setting out to 1 or 1&1/4, engine sounded happier but clutch was constantly spinning.

Air leak? Replace crank oil seals to start?
Low setting may be too lean at 1/4 turn. Richen up the low until the chain stops spinning and you can accelerate without bogging.

Sorry, misread your post. Never mind.

Edit 2- Check the intake boot to see if it's torn. Also check fuel and impulse lines for cracks.
 
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  • #22
New intake boot, fuel line, and impulse line already.

Idle speed screw is the bigger one? Had that set 1 turn out, wil do some more fiddling

Update: cannot back the idle screw out enough to stop sprocket spinning, had it almost all the way out, still spinning
 
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Then slowly back out the low, which will give it more fuel and slow it down. This is what I do, or at least try to.

 
D0AD44D2-62A2-491E-9841-05BBC896A06F.jpeg The STIHL manual states 3/4 on H and 1/4 on L from a lightly-seated position ... If this is a stock saw it should idle and spool up nicely using these settings ... a screwdriver to adjust to suit the mixture richer or leaner will get it close (just worry about the L and LA for now until you get the idle sweet) ... If it doesn’t and is racing there are other issues
 
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Sprocket will spin without a chain on it. Make sure the clutch bearing is in good condition and greased. Also make sure string hasn't wound up between the sprocket and washer, that can cause a bind and spin the chain at idle. I found that on a 046. The bind was so much that I had a hard time cutting it out with a razor blade before there was enough room to get the e clip off the shaft.

the clutch springs could be stretched if the clutch has been overheated.
 
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