Stihl 066 magnum...bad news??

[gunnusmc03]

The 66o kit includes case gasket, 2 sets of crank seals (old/ new crank style) and two cylinder gaskets one for an 064 size and 066/660.
The "set of gaskets" is cheaper as a whole than just buying two new oem seals separately.

 

[gunnusmc03]

Are you the same jason280 that used to post on arf com?

 

[lwn9186]

What all is included in a complete gasket set?

Both seals, muffler gasket, case gasket, cylinder gasket and heat shield on models that require one.

 

[Jason280]

Are you the same jason280 that used to post on arf com?

Yes, same guy...

I was able to get the clutch and oil pump out without too much trouble...






...but haven't pulled the actual seal yet. I did confirm that the seal was leaking....a lot. It wasn't sealing much at all, which would certainly explain my issues. I may try and persuade the shop in the morning to pull it for me, if not, I'll notch a couple screw drivers and pull myself. Do you simply make a small notch, pierce the rubber, turn, and pull out by grabbing the metal portion of the seal?

Also, what is the trick to pulling the flywheel? I was able to get the flywheel nut off without any trouble, but not sure what type of sorcery is required to pull the flywheel itself. I don't have a small enough puller, but could possibly make a few attachments.

 

[z71mike]

Do you simply make a small notch, pierce the rubber, turn, and pull out by grabbing the metal portion of the seal?

Yeah, pretty much.

Also, what is the trick to pulling the flywheel?

I use a 2 jaw puller tool.

 

[Stihlofadeal64]

As has been stated, the seal kit is the way to go on replacing these. You virtually get more bang for your buck, and you have
the other stuff in case you need it. If you drill the metal seal face and insert a screw into it you do need to know that you risk
getting metal shavings into the bottom end, and possibly contacting the bearing. (Many do this, even the dealer that I buy
from often, because I asked them...to each his own). It may be possible that one of the AS guys is near you who has the knowledge
and tools to finish this task in less than 30 minutes. Seal replacement is not difficult, sometimes a hand up is all a guy needs.
If I was closer I'd be glad to do that for you. Hope you get your saw running.

 

[gunnusmc03]

You had some memorable picture threads up on arf

 

[blsnelling]

Those flywheels can seem to be welded on. It will come off with a crack, and you'll think you just broke the crank off. Buy the correct puller. You'll thank yourself later. They're not expensive.

 

[cedarshark]

Before I bought a flywheel puller, I spun the flywheel where i could get a big screwdriver under the thickest part of the flywheel and put some upward pressure on the flywheel. Unscrew the flywheel nut to flush on the shaft and give it a good tap with a deadblow hammer while putting pressure on the screwdriver. This is easier with the girlfriend helping.

 

[Stihlofadeal64]

Buy the flywheel puller and never look back! You'll be glad you did.

 

[Jason280]

I was able to get the flywheel off, and picked up replacement seals for both sides. There's absolutely no sign of a leak on the flywheel side, but there is really no reason not to swap now that the flywheel is off. Still haven't pulled either seal, though, haven't had a chance to notch a couple screwdrivers yet.

 

[blsnelling]

Notice the depth they're set to before pulling them.

 

[pantelis]

Those flywheels can seem to be welded on. It will come off with a crack, and you'll think you just broke the crank off. Buy the correct puller. You'll thank yourself later. They're not expensive.

Yes i agree, and i make the same patends with screws and screwdrivers the results are scratces, and broken parts, finally i take my lesson and i go and buy everyything about servicing stihl and husky.
people must understand that the factory make the tools to make the job perfect and the life easiest, if the job can be done only with patends , they dont make special tools

 

[pantelis]

After chasing a few problems on my newly acquired 066 Magnum, I decided to do a pressure test. I first tried pulling a vacuum on the fuel tank, but didn't have much luck. I never was able to pull a vacuum using a Mity Vac, but was actually able to pressure the system through the fuel line. Not sure if that is indicative of anything, but I don't believe that is my real issue.

I blocked off the carb using a piece of flat aluminum over a double thick piece of rubber inner tube...



...and did pretty much the same with the exhaust:



I tried pulling a vacuum with the Mity Vac through the impulse hose, but was never able to pull anything. I then tried blowing throw the same hose, and definitely have a leak. It was difficult to narrow down, but it sounds suspiciously like its coming from behind the clutch assembly here:



I assume this is likely the clutch side crank seal, but not positive. Assuming it is, what am I in for, and how difficult of a job am I facing? Do I need to tear down the saw further to confirm?

Any suggestions? Thanks!

What are you using for presure? pump, compraised air, what? also are you 100% sure that you have leaks only from clutch seal?
i tell you what i mean sometimes the saw maybe leaking from more positions but the bigger cover the smaller understand?
i have loose small leaks with soapy water, then i put all the saw into water and i find more leaks than with soapy , also clean very good the saw before testing.

 

[cedarshark]

He is using a MightyVac which works well for both the pressure and vacuum test. I also dunk my saws in water while pressure testing. That way you can verify your seals at the exhaust and carb are not causing false readings.

 

[Jason280]

I could "hear" the air leaking around the clutch seal while using very low pressure through the impulse hose, and verified it with soapy water....it sudded up nearly the full circumference of the seal.

 

[pantelis]

I could "hear" the air leaking around the clutch seal while using very low pressure through the impulse hose, and verified it with soapy water....it sudded up nearly the full circumference of the seal.

ok i just tell what have happend in saws that i service

 

[pantelis]

He is using a MightyVac which works well for both the pressure and vacuum test. I also dunk my saws in water while pressure testing. That way you can verify your seals at the exhaust and carb are not causing false readings.

Yes i find small leaks in some crankases with this method, that i lost them with soapy, the carb always i take of and put in water

 

[Jason280]

Good news, potentially.......

I was able to get the clutch side seal removed, and it took a little effort. I tried the "notched screwdriver" method, but didn't have much success. I will admit that I wasn't aggressive with the technique, as I didn't want to mar or scratch the end of the crank. I ultimately drilled a small hole and pulled it with a long wood screw. I was able to get the replacement seal back in place with a 15/16" deep socket, and its is sealing perfectly now. I am able to pull 10 (mm/hg?) of vacuum via the impulse hose, and it is holding pressure.

Now, I just have to get everything reassembled and try the saw. Have to download a schematic, as I can't remember the exact assembly order of the clutch side parts...

 

[drf255]

My 066 leaked awefully on the clutch side. It was a bad bearing that caused the seal to fail.

How does the OP verify that this isn't the cause for his leak?

Not trying to instill anxiety in anyone, but how does he know?