cpr
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One way to do it. Mine are done by changing out throttle shaft linkage plates so the saw can't go wfo on me.
McCulloch Chain Saws
- Thread starter Bruce Hopf
- Start date
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Some of the later plastic McCullochs were made by MTD, the lawnmower company. I guess they did all right for the price range they were in.
Charles - back to post 1723, I looked at the yellow/black one today and the three third port holes are definitely open; same for all of the other 795 blocks I have up in the attic.
This inspired me to look as some other blocks I have laying around, a 1-41 with only two exhaust ports open, only two intake ports open, and one small boost way at the bottom of the inlet. I also looked into a 1-43, three exhaust ports open, two intake ports open, and one small boost at the bottom again.
Very interesting the way McCulloch kept changing things around.
Mark
This inspired me to look as some other blocks I have laying around, a 1-41 with only two exhaust ports open, only two intake ports open, and one small boost way at the bottom of the inlet. I also looked into a 1-43, three exhaust ports open, two intake ports open, and one small boost at the bottom again.
Very interesting the way McCulloch kept changing things around.
Mark
Eccentric
Mister Wizard
Yep. The ones that I've done myself (most of these saws that came to me already had the gov nipped) went that way. I removed the 'hooked' throttle arm from the shaft and replaced it with a 'regular' arm from a front tank Mac or Homelite Zip application Tillotson HL. Did a little heat 'n' bend on the throttle link ('Z' bend) to secure it in the 'new' throttle arm.
Minosi - I really like my 1-72, starts and runs well and I really like the peculiar roller nose bar on mine. I have used it in place of my 066 and prefer the 1-72 for bucking,
And Aaron, it's LOUD and LOUDER.
Mark
And Aaron, it's LOUD and LOUDER.
Mark
DougMN
ArboristSite Operative
I see 55cc Mtd chainsaws at menards along side 55cc remingtons. Other than the trigger saftey and color they look the same. Made in mexico.
Lee, did you bust your knuckles on that beast? I hope that is just a little red paint. Nice saw BTW. Ron
I had hoped to buck a large oak with Betty today. But when you're known as the guy with the BIG saws, you are asked to take on stuff no one else wants to do. I was asked today to buck up the 3' and 4' chunks left by tree services this past summer so I spend the morning standing on concrete with Betty bucking and noodling. Also use my oil challenged favorite PM800 - I've got to come up with a name for it - I have no action photos - just a picture or two of them tucked in bed for the night.
I do have a big MAC question to ask after sawing through a maze of wood sometimes in very awkward positions - is the handle bar an effective chain catcher or should I rig something up? Several times today I found myself in the direct line of fire if a chain should break or be thrown; it made me a little nervous. Ron
PS I swear my PM800 drinks more mix than the SP125C. I ran a good gallon and a half of 32 to 1 through it today. Never re-filled Betty.
Betty
Favorite PM800
All tucked in with their friends
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I do have a big MAC question to ask after sawing through a maze of wood sometimes in very awkward positions - is the handle bar an effective chain catcher or should I rig something up? Several times today I found myself in the direct line of fire if a chain should break or be thrown; it made me a little nervous. Ron
PS I swear my PM800 drinks more mix than the SP125C. I ran a good gallon and a half of 32 to 1 through it today. Never re-filled Betty.
Betty
Favorite PM800
All tucked in with their friends
View attachment 257173View attachment 257174View attachment 257175
The SP125 has a much larger tank, I rather like the fact that I get to take frequent breaks when running the SP81 in larger wood.
I don't worry that much about a broken chain, the few times I have actually broken one or had one jump off the wood took care of it. I do try to stay out of line when I think about it, but normally don't think about it.
Mark
I don't worry that much about a broken chain, the few times I have actually broken one or had one jump off the wood took care of it. I do try to stay out of line when I think about it, but normally don't think about it.
Mark
Eccentric
Mister Wizard
Is this the PM800 that you ran too lean, then recently rebuilt Ron? If so, then I suggest "The Phoenix" or maybe "Rocky".:cool2:
Most of my large frame Mac handlebars have 'nibbles' from tossed chains. Some of my red saws with full-wrap handlebars have plastic or rubber tube sections (all somewhat battle scarred) over that area of the handlebar. I don't give a tossed chain much thought, except to make a mental note to NEVER have my digits on that area of the handlebar where the scars are. Don't have a reason to put my hand there anyways.
I have a tough old friend who had a broken chain related injury while cutting (alone) on a remote ranch. He was fellling a line of large coastal eucalyptus trees with a Homelite 750 running a 48" bar. Hit some embedded steel that broke the chain (.404). It whipped around and nailed him in the knee. Cut him pretty good. He drove his '49 Chevy pickup (manual trans and brakes of course) across the ranch to the house and had the ranch owner drive him to the hospital. I saw his pants leg afterwards. He still cuts alone most of the time, and doesn't wear chaps or ear protection. All he runs is old saws, and he's been doing that since the late 1960's...
I also have come to like the "built in break timer" feature of the 82cc McCullochs. I want them to run out of gas before I do.
I keep on finding 105's.....got this one this week.
very nice condition and 24" original bar.
It's a nice runner but noticed that the plug thread was not in a good shape. Bad news is that the bad thread is already a helicoil thread, so upgrading to a bigger bore is unlikely. Has anyone ever JB welded a helicoil ....or bad idea ?
very nice condition and 24" original bar.
It's a nice runner but noticed that the plug thread was not in a good shape. Bad news is that the bad thread is already a helicoil thread, so upgrading to a bigger bore is unlikely. Has anyone ever JB welded a helicoil ....or bad idea ?
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Eccentric
Mister Wizard
Nice score Roland. There are other 'plug hole repair' threaded inserts that have a larger outer diameter than the Helicoil type inserts. Maybe you can still save that cylinder...
Thanks. I would really like to save that cylinder, it has low mileage anyway. any tips where to find these bigger inserts ?
Eccentric
Mister Wizard
I've seen them on ebay. I'd bet a search for "14 mm spark plug hole repair" or "14 mm spark plug thread" (or something similar) would find some. The inserts I'm talking about are solid, as opposed to the coiled wire Helicoil types.
Here's a quick search I did. I came up with several listings for solid inserts in various lengths (and price ranges) as well as some listings for the Helicoil type inserts.
14 mm spark plug thread repair | eBay
A good automotive/motorcycle machine shop (or racing engine builder) could probably repair your cylinder using one of those solid inserts too.
I keep on finding 105's.....got this one this week.
very nice condition and 24" original bar.
It's a nice runner but noticed that the plug thread was not in a good shape. Bad news is that the bad thread is already a helicoil thread, so upgrading to a bigger bore is unlikely. Has anyone ever JB welded a helicoil ....or bad idea ?
I imagine it gets too hot in that area of the saw for JB Weld to stay.
Warped5
WingNut
Hot? Yah, Roland has that nice avatar back!
Hey Roland ... nice saw too! Don't see too many 105s over here ...
Hot? Yah, Roland has that nice avatar back!
Hey Roland ... nice saw too! Don't see too many 105s over here ...
LOL, she was getting lonely and kept nagging about spending time with the AS boys again....
The 105 seems to have been very popular in Belgium in the seventies. This is my 5 th saw so far.
OldDeadWood
ArboristSite Operative
Ports
Mark
Quit some time ago I thought about the De-tuning of McCullochs by the reduction of ports in
certain blocks.
I may be wrong, but I think that those small boost ports are not used as boost ports but
only to blow some gas and oil (mostly oil) into the wrist pin.
If their are any other thoughts on this please jump in guys.
ODW
Mark
Quit some time ago I thought about the De-tuning of McCullochs by the reduction of ports in
certain blocks.
I may be wrong, but I think that those small boost ports are not used as boost ports but
only to blow some gas and oil (mostly oil) into the wrist pin.
If their are any other thoughts on this please jump in guys.
ODW
Ah the elusive Town and Country muffler. I believe Mark described the two settings as loud and LOUD.
As for the governor, it is an air vane type. The air vane arm (under the flywheel cover) has a spring that forces it towards the flywheel. The arm has a shaft that passes through the lower tank/carb box. On the end of that shaft is a forked arm that bears on a roller attached to the left side throttle shaft arm of the carb. Spring pressure on this governor hardware tries to open the throttle. The trigger has a strong spring that forces the trigger forward (which in turn pulls the throttle link back).
The throttle link attached to the trigger pulls back on the right side 'hooked' throttle arm of the carb because of this spring tension. The trigger spring is stronger than the governor spring, so the trigger 'wins' the 'tug of war' between the trigger and the governor. When you pull the trigger, the throttle link moves forward, allowing the throttle arm to move forward under governor spring pressure. Once the engine RPM's come up enough, the air vane is pushed away from the flywheel and the governor spring is overcome.....closing the throttle. When this happens, the hooked throttle arm rotates away from the throttle link.
Remove your flywheel cover, air filter cover, and air filter. Move the trigger and the air vane with your hand and watch everything to see how all the parts interact with each other. You'll understand it then. It's all a balancing act between two springs (trigger and governor) and the air vane.
On my saws, the governors were all disabled by prior owners cutting the vane off of the governor arm. The 'balancing act' between springs still happens (as the governor arm is still mostly intact, and still has its spring), but the governor arm no longer closes the throttle once the engine reaches a certain RPM as there's no vane to be pushed by the air coming off of the flywheel.
Thank you!
I will definately be looking into this.
Will the same setup be on my 1-70?
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