Mac 125 Competiton saw

[husky394]

Well......What's everybody think? Can the old mac's run with the modern big saws of today in a big cut?

Dennis,

Maybe in something that big, but I don't know of too many places that use logs like that these days, especially in modified production. Almost nobody around here even races Macs anymore. I could have had one for $700 a few years back. The last few that I saw were at least a second behind the top alky strokers, although the wood was nowhere near as big as in your video.

Do you race yours anymore? I'm not trying to be a smartass, just asking.

Chuck

 

[Dennis Cahoon]

Dennis,

Maybe in something that big, but I don't know of too many places that use logs like that these days, especially in modified production. Almost nobody around here even races Macs anymore. I could have had one for $700 a few years back. The last few that I saw were at least a second behind the top alky strokers, although the wood was nowhere near as big as in your video.

Do you race yours anymore? I'm not trying to be a smartass, just asking.

Chuck

You're right Chuck. The mac's don't cold start as well, therefore don't get used much in the small wood cold start contests. That's mostly the type of racing that's done in your neck of the woods. I don't race mine much anymore.

 

[Mr.Suckelfass]

here are my big one's

today i cut with the cp125 some cookies

a very grat saw

 

[keihin2@hotmail]

mac sp 125

hello dennis your mine is the adquires sp 125 no manual information standart please a hp y rpm?tuned what a 22hp capable is possible?thanks friend

 

[keihin2@hotmail]

hey friend

what winner national tome one what your maching is sp 125 wiining national time?please especifications exemple hp y rpm max?thanks

 

[keihin2@hotmail]

mac sp 125

hey dennis no is possible mac from 22hp un modify is high from the engine rpm?16.000rpm?

 

[keihin2@hotmail]

mac sp 125

no is possible mac 125 desarolled 22hp?especifications open ports maxims

 

[romeo]

no is possible mac 125 desarolled 22hp?especifications open ports maxims

NO
maybe 10 or 12 hp at most

 

[HolmenTree]

HA HA, I won't need the translater here.

Three of Bob Walkers 101 Macs came out here to northern Manitoba in 1984. MY 2 older brothers owned and raced 2 of them.Very quick in the 10x10 spruce [3 cuts cold start] 5 sec. At the time my Stihl 090 with 34mm HR alky carb was a second slower.One guy built a 400cc Husqvarna bike saw,so in 1984 I built a 1982 YZ 125 J liquid bike saw with 42mm HD carb. By the time I got all the bugs out of it , all 3 Macs were in pieces with blown cranks.

 

[MacDaddy]

The saw in the pictures is a 101a that had the bridge in the exhaust port cut out, has some mild porting, not a full circle crank, and a old v 4 reed block. if you to make that run get a v 12 with 2 hl's on alky, and have some port work done to it. I cant tell you for a fact but the pipe looks like it could use some work.

Its still a cool saw!



This is some of my port work. Its a intake port for a KTM 450 with a 613 cc kit (6mm stroker, and 11mm big bore)

my shop
Moto Headz Racing

 

[HolmenTree]

I sure wish we had Arborsite or even a computer back in 1984!
Haven't raced my YZ since 1991, still crank her over every summer. Still got plans for it [major weight reduction]. Here in Canada we kept the hotsaw limit to 140 cc [ may have changed since ] .We run 20" or smaller logs here. I remember when I used to test sawchain for Oregon [Gary Walrath ,field engineer]. Gary held the world record for one cut, even saw him cut in a Estacata, Oregon event in 1984. Big heavy Yamaha 292 R snowmobile engine great in the 32" fir log but no good in our small logs.

I remember in the late 70's watching Ron Hartill with his B-Bomb making 3 cuts in a 16" cottonwood, man was he quick ,I can't remember his time but with his hands on log and on the word go he pull started his saw and in a blur he made 3 cuts. I visited Ron at his Vancouver Island home in 1988 and he still had that B-Bomb. The powerhead was no larger in size than an 066 and wasn't much heavier. Ron preached to me that I have to put my YZ 125 on a diet and make it more compact. 2008 it still hasn't been on a diet yet. I think my brothers still want to get their Mac 101 s going again.

 

[romeo]

I sure wish we had Arborsite or even a computer back in 1984!
Haven't raced my YZ since 1991, still crank her over every summer. Still got plans for it [major weight reduction]. Here in Canada we kept the hotsaw limit to 140 cc [ may have changed since ] .We run 20" or smaller logs here. I remember when I used to test sawchain for Oregon [Gary Walrath ,field engineer]. Gary held the world record for one cut, even saw him cut in a Estacata, Oregon event in 1984. Big heavy Yamaha 292 R snowmobile engine great in the 32" fir log but no good in our small logs.

I remember in the late 70's watching Ron Hartill with his B-Bomb making 3 cuts in a 16" cottonwood, man was he quick ,I can't remember his time but with his hands on log and on the word go he pull started his saw and in a blur he made 3 cuts. I visited Ron at his Vancouver Island home in 1988 and he still had that B-Bomb. The powerhead was no larger in size than an 066 and wasn't much heavier. Ron preached to me that I have to put my YZ 125 on a diet and make it more compact. 2008 it still hasn't been on a diet yet. I think my brothers still want to get their Mac 101 s going again.

Welcome old timer. Got any cool old pics of that stuff??? Here is the YZ (94 250) I built for my little bro.

 

[HolmenTree]

I'll have to get the digital camera out and snap a few pics of the YZ ,Maybe tomorrow and download them.
My 125j is a 1982 probably the best year for top end power in the 125s. I just locked open the power valve and polished the exhaust port and put a HD 42mm on it. Factory pipe with 8" stinger. Advanced the timing as far as it can go. Vey strong for a 125 I'm told , yeah I'll send some pics tomorrow, I'll have to blow the dust of it first, lol.

 

[romeo]

I'll have to get the digital camera out and snap a few pics of the YZ ,Maybe tomorrow and download them.
My 125j is a 1982 probably the best year for top end power in the 125s. I just locked open the power valve and polished the exhaust port and put a HD 42mm on it. Factory pipe with 8" stinger. Advanced the timing as far as it can go. Vey strong for a 125 I'm told , yeah I'll send some pics tomorrow, I'll have to blow the dust of it first, lol.

You might as well leave it dirty, I gaurantee the Yamama in that pic doesn't look that nice anymore.

 

[HolmenTree]

Good job on the 250 YZ Romeo. I like the twist grip throttle, looks like a nice setup. You probably had to change the porting on this engine to get the top rpm wailing ?
As you can see here is my 1982 YZ 125.I built this saw in 1984. Notice the black cable running from under the carb, thats the pressurized chain oil tanks control cable connected to the throttle. I got a Schrader blow gun screwed into the bottom of the oil tank piped into the bar pad.The cable is connected to the gun lever, oil releases around 3/4 throttle. Thats a .050 General guide bar on it [made in Tigard Oregon].General made beautiful bars. The long bar on the ground is a Cannon. The chain on the saw is only a practice round filed chain, lol .
You notice the box of files in front of the saw? Thats a full dozen of brand new Windsor chisel bit files [ probably the last dozen in the world] Last of the true edge files. Beautiful file to file with. This saw weighs 42 lbs ,it still needs a major weight reduction. Going to try a new pipe and a newer carb. Thats a 42mm HD on there now. Good project for next winter.Saw was built for cutting 10 inch x 10 inch spruce logs. Times in the late 1980s ; hands on log ,cold start ,3 cuts all down [ no up cut allowed ] within 6" of log in late 4 sec. low 5 sec. time.

 

[romeo]

Good job on the 250 YZ Romeo. I like the twist grip throttle, looks like a nice setup. You probably had to change the porting on this engine to get the top rpm wailing ?
As you can see here is my 1982 YZ 125.I built this saw in 1984. Notice the black cable running from under the carb, thats the pressurized chain oil tanks control cable connected to the throttle. I got a Schrader blow gun screwed into the bottom of the oil tank piped into the bar pad.The cable is connected to the gun lever, oil releases around 3/4 throttle. Thats a .050 General guide bar on it [made in Tigard Oregon].General made beautiful bars. The long bar on the ground is a Cannon. The chain on the saw is only a practice round filed chain, lol .
You notice the box of files in front of the saw? Thats a full dozen of brand new Windsor chisel bit files [ probably the last dozen in the world] Last of the true edge files. Beautiful file to file with. This saw weighs 42 lbs ,it still needs a major weight reduction. Going to try a new pipe and a newer carb. Thats a 42mm HD on there now. Good project for next winter.Saw was built for cutting 10 inch x 10 inch spruce logs. Times in the late 1980s ; hands on log ,cold start ,3 cuts all down [ no up cut allowed ] within 6" of log in late 4 sec. low 5 sec. time.

I didn't keep the twist grip. It actually has a bicycle brake lever housing with a homemade trigger in it. When I made the top handle, I made it out of 1" and the back handle is 7/8" so I could use a set of dirt bike grips. 3 down cuts would be a :censored: . It must be kind of freaky to stand on the bar side.

 

[HolmenTree]

I didn't keep the twist grip. It actually has a bicycle brake lever housing with a homemade trigger in it. When I made the top handle, I made it out of 1" and the back handle is 7/8" so I could use a set of dirt bike grips. 3 down cuts would be a :censored: . It must be kind of freaky to stand on the bar side.

Yes its a little different with bar on left alright but I never cut out or too wide in a contest with it though. Excellent view of the end of the log. I designed this saw originally after Gary Walraths big Yamaha [His 1st hotsaw ], the chain turned backwards.I had the 125s exhaust down and the carb up on top of the saw and the bar on the right. Talk about good chip flow on the downcut and the saw pulling in nice on the upcut. I thought the saw actually cut alot faster that way but a little touchy holding onto though, but the rules changed at our local competition to only down cuts . What happened was some kid built a 400cc Husky dirt bike hotsaw , had the depth gauges down to about 80 thou., and he almost made himself into a twin when he attemped his upcut. So it was only downcuts after that. A lot different cutting a square log too. On the west coast we usually cut 16" lathe turned peelers. I'm planning on putting a rewind on the drive side ,also the fuel and oil tank, then she should be balanced better when I move the top handle position inline with the bar and chain,also bring the rear handle over too.Put the saw on legs & run the pipe under the saw ,stinger exits to the right. Just think this saws going on 25 yrs. old , older then some competitors.

I am trying to post some old pics of my brothers old Mac 101s but scanned pics on this site don't seem to work, so I got an expert coming over in a few days to try and help me. Thats the way it goes us old powersaw guys aren't to up on computers.lol.:newbie:

 

[keihin2@hotmail]

mac sp 125

No picture....it's a V-12 reed block with a burris mikuni, not an HD Tillotson. It had twin HL's when I first got it which actully set up better on the V-12reed block. Short header with a spun kart pipe. At one time it was a National winner, supposedly dyno'ed at 22hp.....Take the 22hp with a grain of salt.

hello dennis is possible 22hp formac 125 rpm?max

 

[keihin2@hotmail]

v-12redd block

No picture....it's a V-12 reed block with a burris mikuni, not an HD Tillotson. It had twin HL's when I first got it which actully set up better on the V-12reed block. Short header with a spun kart pipe. At one time it was a National winner, supposedly dyno'ed at 22hp.....Take the 22hp with a grain of salt.

hello dennis is possible 22hp mac 125 tuned max what rpm max?

 

[PES+]

I heard

That you can really increase an 088s HP by running a second mini spark plug in the compression release hole and delaying it by running a really LONG wire to fire after the main plug.

Also more improvements are possible by using diesel fuel in these engines.......more BTUs per pound so I was told more heat = more power..


HAAAAAAAAAhahaaaaaaa

so why would you wanna mess with 40 year old junk?