064 Funny Sound Diagnosis?

[tallfarmboy]

OK folks, before I tear into my 064, I want to see what the gurus think my problem might be.
Problem: Saw sounds as if something is rattling inside of it... not a loud rattle, but just not right.... it's not clutch or starter rewind. With the rewind pulled, as I rock the flywheel back and forth there is a very slight drag to the flywheel as I turn it around... and you can almost hear a very faint "ping" as it is rocking back and forth.

Please enlighten me as to what you think the problem is before I pull the jug off..

My guess.... piston pin bearing.

Any other guesses before this girl comes apart? Plenty of rep for good guesses.

TFB

 

[showrguy]

could be worn piston..
skirts pinging the cylinder wall ??

 

[kevlar]

loose coil?

 

[striperswaper]

loose nut on the throttle?

 

[rupedoggy]

Bad bearing or bearing cage on the big rod end or crankshaft main beaing. Mike

 

[Grande Dog]

Howdy,
Here's a shade-tree check. Remove the muffler. Locate the piston so the the lower ring is still visible near the top of the exhaust port. Now move the flywheel back and forth to see how much movement you get without the piston moving. If the flywheel doesn't move without moving the piston, it might be carbon build up. If you get a lot of movement of the flywheel without the piston moving, rupedoggy nailed it. If you have access to a pressure/vacuum tester, do some checks before you disassemble.
Regards
Gregg

 

[southbound]

How much gas is in it?????

My old 64 has a chain on the gas cap..I noticed when it was low on fuel either the chain or the fuel filter makes a strange rattle sound....

Just a thought.......

 

[tallfarmboy]

Howdy,
Here's a shade-tree check. Remove the muffler. Locate the piston so the the lower ring is still visible near the top of the exhaust port. Now move the flywheel back and forth to see how much movement you get without the piston moving. If the flywheel doesn't move without moving the piston, it might be carbon build up. If you get a lot of movement of the flywheel without the piston moving, rupedoggy nailed it. If you have access to a pressure/vacuum tester, do some checks before you disassemble.
Regards
Gregg

Good info there Gregg.... Thank you.

This project is officially on the back burner as I'm taking the family to Great Wolf Lodge in Kansas City tomorrow. I will be watching this thread and I will update when I get a chance to tear into the saw.

Thanks guys!

TFB

 

[southbound]

You hear the noise when the saw is not running???

Pull the gas cap look inside and shake the saw...That's what I did lol....

 

[tallfarmboy]

You hear the noise when the saw is not running???

Pull the gas cap look inside and shake the saw...That's what I did lol....

Well, the gas cap does not have a chain attached, so that kinda rules it out.
I'm just hoping that it does NOT require splitting the case to get it fixed. It just feels too good to be something major... Seems like a very low hour saw.

TFB

 

[Sethro]

not a loud rattle, but just not right....

Maybe its the change in your pocket rattling around , thats telling you something ?

 

[willis09r]

Why are you ruling out clutch / clutch springs totally? Maybe let your dealer have a listen.......

 

[sefh3]

Fuel filter rattling in the tank. Crank bearing cage going on a joy ride.

 

[wigglesworth]

I had a MS 460 that the clutch was worn enough that it rattled like crazy, even with new springs. I had to replace it.

 

[tallfarmboy]

Why are you ruling out clutch / clutch springs totally? Maybe let your dealer have a listen.......

Letting the dealer listen to it.... not a real bad idea. As much as I enjoy working on things, I wouldn't mind at all if the saw got a clean bill of health after taking it to a dealer.

TFB

 

[tallfarmboy]

See pics of piston and cylinder....

I am wondering if the piston was the reason for the noise... it has some decent scuffing on it. I can still see some cross hatch on the cylinder... should I reuse the cylinder? I am planning on at least replacing the piston...

Thanks for the advice!
TFB

 

[lwn9186]

Piston is missing the top ring! Try cleaning the cylinder up with some acid and sanding, put a new piston and rings in it.

 

[tallfarmboy]

Piston is missing the top ring! Try cleaning the cylinder up with some acid and sanding, put a new piston and rings in it.

Hahaa.... yes, good eye. I removed the top ring to check ring gap in the cylinder... no need to worry about that.
TFB

 

[wigglesworth]

Does the top of the piston have little dents in it? That skirt damage looks like a bearing failure to me.

 

[tallfarmboy]

No dents on top of the piston.... both bearings on the rod are good. Big and little. Anyway that the damage could have been due to a lean condition or poor fuel/ straight gas?

The main bearings are ball bearings, correct??

TFB