McCulloch Chain Saws

[MAC 7-10]

Mark

I really like what you did to the chain guard, looks a lot better than the stock unit., sort of resto mod. What do you consider a good compression range for 7-10,s I have a thick ring version and a thin ring version. of the saws. They cut so good how do you tell if they are getting tired?

 

[heimannm]

I haven't seen many of the 10 Series saws over 160 PSI but I've heard reports of 180+. I do have several broken starter housings around to attest to the benefits of using the compression release (or not) on the 82cc models. They they generally still run pretty well down around 125 PSI. Much below 110 and performance suffers a lot.

If everything else is in good shape, the most noticeable issue with a low compression saw (other than being easy to pull over) is starting issues. I had a PM55 that would not start with the compression release activated, but would start, run, and cut with the valve closed. I freshened that one with a new piston and cylinder and it is still a favorite saw when I need some serious 16" bucking or noodling.



Mark

 

[Syncop8r]

I'm missing the sound of Macs...

 

[MAC 7-10]

That's a picture of a Mac lovers candy store

 

[rwoods]

I'm missing the sound of Macs...

So do I. I’ve been sidelined with a knee injury and a family medical issue since early October.

Hope to get back to cutting soon.

Ron

 

[rwoods]

Horning in on the compression question, my PM 700 ran well at 135 psi.

My 165 psi PM 800 runs decent with the DSP MIA. Of course, I don’t intentionally run it that way.

Ron

 

[Maintenance supervisor]

The 82cc I did with LRB piston has thick rings and its got some wicked compression! I was able to salvage the eom bearings for that piston.
Idk how much the thick rings play a part but I've learned to not forget the dsp valve with that one.

 

[MAC 7-10]

Thanks for the info guys, Sounds like any thing north of 130 is golden. I know I cannot start my 7-10"s without the DSP in.. I have a pristine Mac 8200 Q port I bought from a good friend. Acquired just before my heart attach. I am 145 lb now after heart attach so I am working out to start saw, but will take suggestions on an easy start method. Forget drop starting then I would have shoulder problems tooo. I think a battery start ratcheting starter system would be nice for us over the hill thrill seekers. Hope you get back to cutting soon Ron, it is good therapy. Yep there is nothing like the sound of Mac's and the smell of Castor oil if your real lucky. An early Merry Christmas and happy new year to all

 

[knightmax]

So do I. I’ve been sidelined with a knee injury and a family medical issue since early October.

Hope to get back to cutting soon.

Ron

Sorry Ron. Glad you are doing better.

 

[heimannm]

Jim - The Q port theoretically does away with the need for a DSP valve.

Throttle latched open, choke on, saw on the ground, put your left foot on the lower brace ( support under the rear handle), hold the saw down with your right hand, and pull the starter with your left hand. Gently pull the engine over until you feel it coming up on compression, then pull like you mean it.

If the saw has not been run in a while, put a teaspoon of fuel mix into the carburetor and gently pull it over a few times, the follow then procedure above less the choke. You may have to prime it a few times to get the carburetor pumping or, if you can get to the choke quickly enough you may be able to keep it running long enough to get the fuel pumping.

Mark

P.S. Still waiting on the mail...

 

[knightmax]

Jim - The Q port theoretically does away with the need for a DSP valve.

Throttle latched open, choke on, saw on the ground, put your left foot on the lower brace ( support under the rear handle), hold the saw down with your right hand, and pull the starter with your left hand. Gently pull the engine over until you feel it coming up on compression, then pull like you mean it.

If the saw has not been run in a while, put a teaspoon of fuel mix into the carburetor and gently pull it over a few times, the follow then procedure above less the choke. You may have to prime it a few times to get the carburetor pumping or, if you can get to the choke quickly enough you may be able to keep it running long enough to get the fuel pumping.

Mark

P.S. Still waiting on the mail...

I have never been able to effectively start a saw like that Mark (saw on the ground). Right up to a 125, I do it standing. I can't get my big foot in the handle/lower brace area and it always slide off the inch of toe that fits so I just stand up, hold the handle bar with my left and pull with my right (on LH starts). Uncle always did it the way you described. He even told me once my foot was to big lol.

 

[Jeffrey F.]

I recently loaned a 610 & a 650 to a good friend of mine & he was really impressed with the 650.The 610 ran for a bit & then died & he couldn't get it restarted.The 650 is hard starting & he said he did some reading up on the 600 series saws & told me that it was a common problem for the saws to have a vapor lock problem because the fuel tank is so close to the engine.I've never heard of this or experienced it.He said the saw will start cold without a problem,but when it's hot/warm is when it's difficult to start.I've never had either this particular 610 or 650 out cutting.

I've never had that issue with my 650 seems strange cause you would think that the magnesium would act like a heat sink and spread out a cool off stuff !
The 650 was and still is my most reliable saw. Besides my Stihl 290 Farm Boss.

 

[Jeffrey F.]

Jim - The Q port theoretically does away with the need for a DSP valve.

Throttle latched open, choke on, saw on the ground, put your left foot on the lower brace ( support under the rear handle), hold the saw down with your right hand, and pull the starter with your left hand. Gently pull the engine over until you feel it coming up on compression, then pull like you mean it.

If the saw has not been run in a while, put a teaspoon of fuel mix into the carburetor and gently pull it over a few times, the follow then procedure above less the choke. You may have to prime it a few times to get the carburetor pumping or, if you can get to the choke quickly enough you may be able to keep it running long enough to get the fuel pumping.

Mark

P.S. Still waiting on the mail...

I kinda do the same except I have some premix in a lever squirt oil can and use that. My 038 Mag ll is a saw that I have to do that procedure every time cold.

 

[heimannm]

My "piston pump" oil can that I have filled with mixed fuel delivers about 1/2 a teaspoon for each pump once it is primed...

 

[edju1958]

I've never had that issue with my 650 seems strange cause you would think that the magnesium would act like a heat sink and spread out a cool off stuff !
The 650 was and still is my most reliable saw. Besides my Stihl 290 Farm Boss.

My buddy seems to think that whatever he reads on the web is gospel.He came by with the saws yesterday & I had him fire up the 650 (I also put a brand new fuel cap on to appease him_ & the saw stuttered when he tried to throttle it up.I turned out the lo screw a bit & it throttled up nicely.I had him shut it off & restart it & it took about 4 pulls,but I don't believe he used the throttle lock.

He wants to buy my 650,but it's the only 650 I have.I must have a dozen other 600 series saws.

 

[Jeffrey F.]

My buddy seems to think that whatever he reads on the web is gospel.He came by with the saws yesterday & I had him fire up the 650 (I also put a brand new fuel cap on to appease him_ & the saw stuttered when he tried to throttle it up.I turned out the lo screw a bit & it throttled up nicely.I had him shut it off & restart it & it took about 4 pulls,but I don't believe he used the throttle lock.

He wants to buy my 650,but it's the only 650 I have.I must have a dozen other 600 series saws.

My 650 is original owner, me. I've had it many many many years, got it brand new. 1st saw ever owned.

 

[MAC 7-10]

Hey guys thanks for all the advice and stories. I think the key is like Mark said PULL LIKE YOU MEAN IT, I 'll get that sucker started some way. I am going to wait untll the holidays are over just in case it wins the first round. Before starting a saw that has sat a long time I use a small hyperdermic needle 0-1 cc I get from my veterinarian. I like it for working on small cc engines, less likely to hydro lock on first pull. If you live in a big city you can get them free by looking in gutters, just kidding of coarse, no second hand needles for my Mac's

PS Mark when you get the mail, check should have same date as envelope, just curios

 

[Syncop8r]

He wants to buy my 650,but it's the only 650 I have.I must have a dozen other 600 series saws.

You must only lend out the 610s.

 

[Maintenance supervisor]

I built a clone 090 a few years ago, I had .045 taken off the cylinder and ported it myself. Ive broken 4 pull cords and shattered 2 handles, pulled the cord through a Stihl D handle too.
To say that it's difficult to start is a dramatic understatement. Using all the aforementioned tricks always leads to success, my foot also doesn't sufficiently fit in the rear handle. I saw someone do a trick by placing their axe handle in the foot pad and then step on that to hold the saw down. That trick works very well as it allows you to take a wider stance.

 

[Squareground3691]

I built a clone 090 a few years ago, I had .045 taken off the cylinder and ported it myself. Ive broken 4 pull cords and shattered 2 handles, pulled the cord through a Stihl D handle too.
To say that it's difficult to start is a dramatic understatement. Using all the aforementioned tricks always leads to success, my foot also doesn't sufficiently fit in the rear handle. I saw someone do a trick by placing their axe handle in the foot pad and then step on that to hold the saw down. That trick works very well as it allows you to take a wider stance.

I like resting the bar tip on a log , and throwing the PH away from me and pulling hard an fast , especially like the kart saws, always seems to work well,