MS660.........The saw from hell

[TRX]

Bought on ebay for what I thought was a good price because it would not start. Owner bought it at an auction from what she said was a professional logger. Received the saw, no compression and no spark.

First thing I noticed is the case does not have the Stihl logo on it. In fact, none of the parts have the Stihl logo other than the plastic with stickers, and the little bracket for the chain tensioner has the Stihl logo. Is this normal or did I buy a Farmetec with Stihl stickers?

Installed new crank bearings. New crank seals. New piston. New rings. New head gasket..............Still no compression.

Pulled cylinder and put copper gasket sealer on head............Still no compression.

On top of that, new flywheel, new ignition coil, and new spark plug............Still no spark.

Banging my head against the wall here. Any suggestions?

 

[Mad Professor]

You s

Bought on ebay for what I thought was a good price because it would not start. Owner bought it at an auction from what she said was a professional logger. Received the saw, no compression and no spark.

First thing I noticed is the case does not have the Stihl logo on it. In fact, none of the parts have the Stihl logo other than the plastic with stickers, and the little bracket for the chain tensioner has the Stihl logo. Is this normal or did I buy a Farmetec with Stihl stickers?

Installed new crank bearings. New crank seals. New piston. New rings. New head gasket..............Still no compression.

Pulled cylinder and put copper gasket sealer on head............Still no compression.

On top of that, new flywheel, new ignition coil, and new spark plug............Still no spark.

Banging my head against the wall here. Any suggestions

You should have sent the Chinesium POS back to the Ebay seller.

 

[SimonHS]

Pictures please.

Is the decomp valve leaking?

 

[buzz sawyer]

Pictures please.

Is the decomp valve leaking?

Or missing? Are you sure the wire to the kill switch isn't grounded somewhere?
Are you using a compression tester?

 

[rogue60]

Peel the Stihl stickers off and stick them on the fridge as a bitter sweet reminder not to make that mistake again.
And as for the chinesium junk saw put it out on the curbside and watch in amusement as some sucker pulls up and grabs it and makes out like a bandit

 

[MnSam]

Seriously? Still no compression or spark? If you are able to do all that work you are capable of figuring out what is wrong.

 

[ZeroJunk]

You have quite a bit of time to make a claim as misrepresented. Unless the description indicates specifically that the saw is not manufactured by Stihl then eBay will instruct the seller to give return authorization . And, if he does not they will refund your money anyway after a time period.

Sort of a moot point since you have been working on it.

 

[user 122190]

Seriously? Still no compression or spark? If you are able to do all that work you are capable of figuring out what is wrong.

I was thinking the same. Installing new rings and piston, etc. is not heart surgery. Maybe a new compression gauge should be on order?

 

[RedneckChainsawRepair]

Sounds like a scammer got ya.

Might want to start filing now with PP and EB if you bought from there and was listed as OEM saw.

 

[Ironhorse]

Farmertec makes some great aftermarket parts. I throw them on my 066/660 all the time.

 

[TRX]

Bought the saw not working, so knew there were problems. Seller is not in saw business and did not know it wasn't a Stihl. She did however refund $200 so now I'm into it for slightly more than a new Farmetec including parts. In retrospect, I should have reassembled the saw and returned it for a full refund, but that is no longer an option.

As for compression, put both the OEM bolt in hole for decompression valve, as well as a new valve. Neither had any effect. Also thought compression gauge might be leaking but there is very low resistance when pulling on rope.

Thoroughly inspected cylinder, and could not see any cracks in it, but it's possible so might need a new cylinder. Bought the Hyway piston with Caber rings, so will probably go with Hyway cylinder.

As for no spark, followed instructions from manual and pulled the hot lead from coil. Nothing. Removed ground wire as well, and still nothing. The only thing I can think of is I got a defective coil.

Not fond of spending another $150, but also not fond of throwing away all the money I already spent too.

Opinions?

 

[Dennisthemenace]

Who buys a saw sight unseen? Me ONCE

 

[ZeroJunk]

Dumb question. Are you sure you put the right piston in it ?

 

[user 122190]

Bought the saw not working, so knew there were problems. Seller is not in saw business and did not know it wasn't a Stihl. She did however refund $200 so now I'm into it for slightly more than a new Farmetec including parts. In retrospect, I should have reassembled the saw and returned it for a full refund, but that is no longer an option.

As for compression, put both the OEM bolt in hole for decompression valve, as well as a new valve. Neither had any effect. Also thought compression gauge might be leaking but there is very low resistance when pulling on rope.

Thoroughly inspected cylinder, and could not see any cracks in it, but it's possible so might need a new cylinder. Bought the Hyway piston with Caber rings, so will probably go with Hyway cylinder.

As for no spark, followed instructions from manual and pulled the hot lead from coil. Nothing. Removed ground wire as well, and still nothing. The only thing I can think of is I got a defective coil.

Not fond of spending another $150, but also not fond of throwing away all the money I already spent too.

Opinions?

Most people are overly fond of blaming the coil. These are the same people that buy multiple batteries before looking for the next easy to blame problem.

I had a neighbor call me up last week to have me help figure out how to install a new thermostat in his wall heater. After spending some time thinking about it, I went back to the basics. It was a breaker in the breaker box. As soon as I started to ask about the breakers, he started to go thru his parts box, pulling out spare/old breakers. Turns out the breaker wasn't popped, it was off. Start with the simplest and at the beginning.

 

[Syflan]

Intriguing... There are only so many places a cylinder can leak, and it sounds like you've looked at most of them. Since the saw came from a logger at one point, I wonder if it was hot-rodded at one point and the ports are more than a smidge too big.
If you squirt some oil straight into the cylinder, do you get a couple of rotations worth of compression?

 

[buzz sawyer]

Did you do a leak/vac test? How about squish? Maybe wrong connecting rod? Just brainstorming.

 

[TRX]

"Most people are overly fond of blaming the coil. These are the same people that buy multiple batteries before looking for the next easy to blame problem."

New flywheel, new coil, and tried two brand new NGK plugs, but no spark. The ignition system is really basic, so if it is not a defective coil, ????

 

[TRX]

Poured an ounce of oil into the cylinder, and no still no compression.

That tells me there is a hairline crack, or the threads around the plug hole or decompression hole got hot and became deformed. Going to order a new Hyway cylinder, and will let everyone know if that fixes it.

Thank you for all your help!

 

[user 122190]

"Most people are overly fond of blaming the coil. These are the same people that buy multiple batteries before looking for the next easy to blame problem."

New flywheel, new coil, and tried two brand new NGK plugs, but no spark. The ignition system is really basic, so if it is not a defective coil, ????

Maybe it is. I'm not there and cannot say. If you feel that you have tried all lower hanging fruit, then by all means buy a new coil.

What I am saying is that it is usually something very simple, and can be accomplished by inspection and cleaning and just something else that is so simple you might be astounded. My circuit breaker box neighbor is still trying to wrap his head around such a simple solution after he convinced himself it was the thermostat(s). BTW there were 3 of them that failed all at the same time for the same reason. The solution of setting the one breaker solved all three heater problems at the same time. Amazing. Who knew????

 

[Vintage Engine Repairs]

Work methodically..

Test the primary and secondary windings on a mm, sometimes the seniconductor material and resistors on the primary can give skew readings, but in my experience more often than not I get good ones.

As for compression, if someone has been in there and it’s AM parts - measure squish, then check cylinder diameter, piston diameter, piston length, piston ring end gap and see if it all matches up to oem specs.

Pressure and vacuum test it next. 7 psi and 15 inHg any leaks?

You’ll never fix it by giving it a birthday with new parts.

I understand though, you’re in a frustrated and tense mood wanting it to work - I can fully relate, but sometimes you can’t see the forest for the trees.