Ms660 compression?

[JTM]

I'm on this site to learn, I'm young and I have a limited amount of knowledge. I'll be the first to admit that. After reading posts here is when I decided to buy an ms660 and start milling, instead of hacking everything up for firewood. Before I milled I took it to a local reputable shop and had the carb tuned. Told him what I was doing and he said he'd take care of me. I've since found a better shop a little farther away but it's worth the drive.



I got the saw and had the carb work done in February, so 45-50 in the shop vs last weekend in 85 and full sun.

I usually tend to hang out in the milling and firewood sections of this forum, clearly I should have been in here researching. I'm beating myself up because I THOUGHT I was doing everything right, turns out I wasn't! Bummer!

Shouldn’t have been a problem with the tuning then. It may have been a bit rich. But for milling that’s a good thing. Sounds like something else maybe an air leak.

 

[JTM]

Just out of curiosity, as the air temperature goes up, would you usually want to richen, or lean out, the mixture?

On one hand, as the temperature goes up, the amount of oxygen in a given volume of air decreases, so that suggests to me that you would want to lean the carb ... but fuel also cools the engine, and cooling becomes more critical as the temperature goes up, so I'm not sure...my hunch says, "As temp increases, richen the carb." So which is it?

Just trying to learn here. I've always had my saw guy set and check my tuning, but I want to learn to do it myself better.

When it’s cold you need to go richer. When I use my 660 in the winter I tune by ear in the cut. When I mill I put a tachometer on it and set to 12,500.

 

[Canyon Angler]

Thank you, JTM. I just ordered a digital tach so I can start doing this myself.

 

[drf255]

I'm on this site to learn, I'm young and I have a limited amount of knowledge. I'll be the first to admit that. After reading posts here is when I decided to buy an ms660 and start milling, instead of hacking everything up for firewood. Before I milled I took it to a local reputable shop and had the carb tuned. Told him what I was doing and he said he'd take care of me. I've since found a better shop a little farther away but it's worth the drive.



I got the saw and had the carb work done in February, so 45-50 in the shop vs last weekend in 85 and full sun.

I usually tend to hang out in the milling and firewood sections of this forum, clearly I should have been in here researching. I'm beating myself up because I THOUGHT I was doing everything right, turns out I wasn't! Bummer!

We all learn. Hell, my old way of tuning a saw was to turn the H in till it screamed, then open 1/8 turn. I was an idiot (sometimes I still am).

You’ll need to learn ear tuning if you wanna mill, plain and simple. It will come naturally after a while, but it’s not instinctive.

A saw that’s rich enough will misfire out of the cut and have a muffled kinda tone when cutting. I think Brad has a tuning video somewhere.

Milling is just the most amount of stress one can put on a saw, plain and simple.

Pull your jug and let’s see. Chances are you will be able to save it and use a $50 Meteor piston to replace the oem.

In your case, you may want to get an AM P&C and use it till you get more experience. Keep the OEM jug on a shelf. Once it clicks, you can reinstall for more power. I ran an AM setup on an 066 for 5 years. I had no idea that it was even AM, or what the difference was.

 

[drf255]

Here’s an old video of the first saw I ever ported. You should be able to hear the tune. This is a proper tune.

 

[Tin-knocker]

Just out of curiosity, as the air temperature goes up, would you usually want to richen, or lean out, the mixture?

On one hand, as the temperature goes up, the amount of oxygen in a given volume of air decreases, so that suggests to me that you would want to lean the carb ... but fuel also cools the engine, and cooling becomes more critical as the temperature goes up, so I'm not sure...my hunch says, "As temp increases, richen the carb." So which is it?

Just trying to learn here. I've always had my saw guy set and check my tuning, but I want to learn to do it myself better.

Higher temperature or higher altitude you would need to lean out the carb. Lower temperature or lower altitude you would need to richen.

 

[rupedoggy]

Air density

 

[Spanky]

Here’s an old video of the first saw I ever ported. You should be able to hear the tune. This is a proper tune.

Did you ever get it right looked slow to me