Stihl 660 Compression

[a. palmer jr.]

Are you kidding me? I am 70 years old and I don't have to find young guys to start saws for me. I don't care how much compression they have.

I'll raise you by three. I've been pulling on these saws for two or three days now and arm was getting tired and a little sore, that's all. That's where I had to take the saw anyway so figured why not? I've had several saws with around 200 compression and started them fine. I didn't check the compression on this one..By the way, the young guy had a little trouble with it.

 

[ZeroJunk]

Does it have the stock ignition coil ? My flat top 066 kicks back pretty bad , but I was thinking that the MS660 had some timing retardation built in to the coil to help with that. At least I have not found the MS660's I rebuilt near as bad as a flat top 066 or 064 . May be wrong though.

 

[a. palmer jr.]

This one is the flat top 066 and I have another one just like it to rebuild. One thing I'm gonna do differently is buy the stock size cylinder kit versus the big bore kit. I thought the big bore might have raised the compression some.

 

[a. palmer jr.]

Something about these Stihls kicking back: I have the 066 that kicks, an 034 with a big bore, doesn't kick, an MS250 that kicks back and a 390 that does and another one that doesn't. Kinda odd, sometimes I think it's how rich the carburetor is set. When I rebuild one I generally set them a little rich until after break in..

 

[jmssaws]

Coils and flywheels will vary on how much advance there is,especially on the aluminum flywheel 066.
Lots of different coils

 

[a. palmer jr.]

Yeah, all the stuff is mass produced and they're close but not identical sometimes..

 

[blsnelling]

This one is the flat top 066 and I have another one just like it to rebuild. One thing I'm gonna do differently is buy the stock size cylinder kit versus the big bore kit. I thought the big bore might have raised the compression some.

Not likely.

 

[Wood Doctor]

I ran into a similar situation with two 066's that I rebuilt. The first start takes a monster man and I could hardly do it. After running for awhile, I could start it far more easily. That's kind of the way it is with big saws. I always dread the first start from a rebuilt engine with a new top end.

 

[ZeroJunk]

This one is the flat top 066 and I have another one just like it to rebuild. One thing I'm gonna do differently is buy the stock size cylinder kit versus the big bore kit. I thought the big bore might have raised the compression some.

Well, it is the nature of the beast. The title said 660 so I thought you were dealing with a later version. With my 066 you have to scream bonsai and just go with it. If you don't get it over it will jerk the handle back and take the meat off your fingers with it. A MS660 is much easier to deal with. It is a timing issue more than compression.

 

[a. palmer jr.]

Not likely.[/QUOTE

Well, it is the nature of the beast. The title said 660 so I thought you were dealing with a later version. With my 066 you have to scream bonsai and just go with it. If you don't get it over it will jerk the handle back and take the meat off your fingers with it. A MS660 is much easier to deal with. It is a timing issue more than compression.

When I wrote the title I thought the 066 and 660 were the same...anyway, I took it back to the owner, thanks for the replies and good advice as usual!

 

[lone wolf]

Are you kidding me? I am 70 years old and I don't have to find young guys to start saws for me. I don't care how much compression they have.

Some people have injuries and arthritis or who knows?

 

[a. palmer jr.]

I'm 73 by the way and do have a sore arm from time to time. I already have one long term injury from being stupid, don't need another...

 

[CR888]

Could try a thicker base gasket to bring down psi.... I have a M/Mind 660 and it's a bear to start cold, I pull it over slowly with comp button pressed to get the piston in a good place so it don't bite. Once at running temp it restarts a LOT easier.

 

[rupedoggy]

Mea culpa

 

[ZeroJunk]

When I wrote the title I thought the 066 and 660 were the same...anyway, I took it back to the owner, thanks for the replies and good advice as usual!

Well, the later model 066's and MS660's are the same for all practical purposes. But, the old flat top 066's had a dumb ignition fixed at 25 degrees or so BTDC.

 

[a. palmer jr.]

Well, the later model 066's and MS660's are the same for all practical purposes. But, the old flat top 066's had a dumb ignition fixed at 25 degrees or so BTDC.

Yeah and if you run it a little rich it'll fire even sooner...I've had a couple of Homelite 330s that do the same thing, just turn the idle screw in a bit and it isn't as bad. I'll bet the 044 had the same ignition, they're well known for kick backs. I'll let you guys know how the next one turns out after the parts arrive and I get it together, a short job.

 

[GoBigBlue1984]

Take this a little further......I robbed the coil and vent and carb off a strong running 660 to fix a 660 for a customer in a pinch. His wj-69 had failed (just got a kit for it the other day) so I ordered a zama clone from Dave to put on mine. Also put on a new OEM vent. The coil came off his and I just assumed it was good and put it back on mine. There are both composite flywheels and I've got good spark.
Here's where the problem arises. Idles sporadic, high/low like an air leak. Throttles really rich and bogs after a few seconds. Smokes as well from muffler with noticeable flooding. Upon killing it, it will puff and back flow fuel out of the carb. Enough that you can feel it on your arm.

Ignition issues.......that's my guess. I've got a couple of coils on the way.

 

[lone wolf]

I'm 73 by the way and do have a sore arm from time to time. I already have one long term injury from being stupid, don't need another...

Go get a Stihl MS 241C and you can thank me later.

 

[a. palmer jr.]

Go get a Stihl MS 241C and you can thank me later.

The arm thing is only temporary, not a permanent disability. Probably just overused it lately from all the chainsaw rebuilds and starting them afterward. I had a Stihl saw with a "C" and I didn't like it, also had the tool less chain adjuster and I didn't like it either. Just wondering why these Stihls are hard to pull and kick back when other saws cut just as good and don't have that problem. I've had several big Husqvarnas that cut as good as the big Stihls I've owned and never a problem.

 

[jmssaws]

Take this a little further......I robbed the coil and vent and carb off a strong running 660 to fix a 660 for a customer in a pinch. His wj-69 had failed (just got a kit for it the other day) so I ordered a zama clone from Dave to put on mine. Also put on a new OEM vent. The coil came off his and I just assumed it was good and put it back on mine. There are both composite flywheels and I've got good spark.
Here's where the problem arises. Idles sporadic, high/low like an air leak. Throttles really rich and bogs after a few seconds. Smokes as well from muffler with noticeable flooding. Upon killing it, it will puff and back flow fuel out of the carb. Enough that you can feel it on your arm.

Ignition issues.......that's my guess. I've got a couple of coils on the way.

I have tried a few of them am carbs and got pretty much the same results.