Author Topic: What saw are you looking for ?  (Read 1216 times)

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Offline Al Smith

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Re: What saw are you looking for ?
« Reply #30 on: January 21, 2015, 09:20:03 pm »
20 or 30? My ex wife must have had 200 pairs ,good grief .

Saw wise I bought a Mac 1000/Partner P100 from flea bay a guy advertised on another site .I need it about like I need a hole in the head but I took a chance on it .

The saw is relatively rare so I thought why not .Any more with the hodge podge of stuff I have it takes something very few people have to interest me .This one did .If it's screwed up I'll fix it,always have but some things just take longer than others . ;)

Offline aclarke

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Re: What saw are you looking for ?
« Reply #31 on: January 21, 2015, 10:01:07 pm »
Al, does the  p100  exhaust port have a groove machined in the roof of the port.  If I remember correctly the cylinder I worked on for Bob had that feature. Seemed like the saw designers wanted more exhaust duration without the drawbacks.  The slot/groove started dumping exhaust early without loosing all cylinder pressure

Offline Al Smith

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Re: What saw are you looking for ?
« Reply #32 on: January 22, 2015, 08:43:51 pm »
It's in shipment Adam,not here yet .

I think you are refering to an eye brow port .If so from what I gather it allows for the exhaust to self relieve the cylinder pressure at cranking speeds but has little effect at running speeds .Time /open/speed thing .

The Mac 805 cylinder had an eye brow and the later model 850 cylinder did also .The replacement after I straight gassed it with a prime was an early 850 which didn't have an eyebrow .

Now it could theoretically act somewhat like an exhaust boost port but I really can't say it would or would not .

Offline aclarke

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Re: What saw are you looking for ?
« Reply #33 on: January 22, 2015, 10:31:56 pm »
Al, I believe were.talking about the same thing
 Kinda interesting in that it also would allow for starting the exhaust event earlier without the side effects of having a high exhaust port. Be interesting  experiment with....

Offline Al Smith

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Re: What saw are you looking for ?
« Reply #34 on: January 23, 2015, 05:31:16 am »
I never checked the timing on the 850 but if it's like the others of the ten series it's at 96 after .Some might say that's too high for good torque but I think the ten series made up for it with larger transfers plus better sweep and distrubution .

I'm going to spend some time on this Mac/Partner to see what makes it tick .

Offline Eccentric

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Re: What saw are you looking for ?
« Reply #35 on: January 23, 2015, 03:24:09 pm »
A PM850  is certainly not lacking for torque.  Same with the earlier SP-81.  My SP-81 is one of my favorite saws.  I recently rebuilt a PM-850 for a friend.  Very strong 82cc saw.
-Aaron

For older saws:
Tune the H side so that it 4-strokes (burbles) at WOT unloaded and just cleans up when under load.
When you lift cutting load, the saw should immediately revert to 4-stroking.  Fine tune the transition point for the wood you're cutting.

Offline aclarke

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Re: What saw are you looking for ?
« Reply #36 on: January 23, 2015, 09:48:35 pm »
Watched a couple of videos of the pm-850 on YouTube.  Seems like they run strong!

Offline Eccentric

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Re: What saw are you looking for ?
« Reply #37 on: January 24, 2015, 01:02:04 am »
They are.  Come up north for our GTG and you can run one (and my SP-81, and my Super 250, and my Poulan 8500, and.....).:D
-Aaron

For older saws:
Tune the H side so that it 4-strokes (burbles) at WOT unloaded and just cleans up when under load.
When you lift cutting load, the saw should immediately revert to 4-stroking.  Fine tune the transition point for the wood you're cutting.

Offline aclarke

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Re: What saw are you looking for ?
« Reply #38 on: January 24, 2015, 10:15:48 am »
Sounds cool!  When is it?

Offline Eccentric

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Re: What saw are you looking for ?
« Reply #39 on: January 24, 2015, 05:57:18 pm »
Last weekend of October 2015.  On HWY 29 between Calistoga and St Helena.  Bothe Napa Valley St park.  That's where I do volunteer work at.  We do volunteer work days and GTG's there.  The park lost state funding/manpower a couple years back.  Now it's operated by a county open space district.  Most work is done by volunteers.  It's a work in progress.  I'm proud to have 'gotten in on the ground floor' of it....

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0CCEQFjAA&url=http%3A%2F%2Fnapavalleystateparks.org%2F&ei=1SPEVMnbHoyfgwT0r4DADg&usg=AFQjCNH8SRv4q16CVuwB-vwzRdNlqXBgdQ&sig2=MvxH1sbqoasYuV6fATiRew&bvm=bv.84349003,d.eXY

-Aaron

For older saws:
Tune the H side so that it 4-strokes (burbles) at WOT unloaded and just cleans up when under load.
When you lift cutting load, the saw should immediately revert to 4-stroking.  Fine tune the transition point for the wood you're cutting.