McCulloch Chain Saws

[2broke2ride]

I do believe that is the exhaust side in looking at the other picture I have. I wish I still had the damn piston[emoji35]
It has always been my understanding, as a mechanic, that mending a rod is far easier than people think. Especially when uneven forces are applied.
I have personally seen two Ford 4.2 engines hydro lock from a leaking intake gasket and bend a rod from no more that the force of the starter. The result is slightly lower compression in the cylinder and a light misfire at idle due to the uneven compression.

 

[svk]

SP81. What is this extra stud for?

 

[2broke2ride]

That is a chain brake cover missing the the brake flag. Looks like the band is still peeking out from behind the cover.

 

[svk]

That is a chain brake cover missing the the brake flag. Looks like the band is still peeking out from behind the cover.

Appreciate it. Didn’t even realize these came with a brake!

 

[PogoInTheWoods]

wrong rod?

From what I dug up this morning 65401/85352 is the common rod assembly across the 10 series until the 82cc saws

 

[Jethro 2t sniffer]

I spose jamming something in the exhaust port and a big strong arm bar on the clutch or flywheel nut could well be a scenario to bend the rod.

I hope my 7-10 runs ok after a rebuild its certainly got me worried a bit

 

[Jethro 2t sniffer]

Has anyone got some 700 or 7-10 or 6-10 cylinders lying around? Would love to see some pictures of the porting of them all together. Can a 700 be ported to run like a 7-10? I was reading an old thread somewhere and a chap was saying the 7-10 has an extra transfer port but the thread went dead and no pictures can anyone here confirm that?

 

[PogoInTheWoods]

Hear, hear!

If there are porting differences, of course. About as close as I could get would be to tear down a PM700 (which would have the windowed piston) and a 10-10 which should have what I now call the "port hole" piston with the complete skirt. If there is a drastic difference in cylinder porting between the two piston designs, it may well apply to Kevin's 7-10 situation as I've been theorizing.

 

[hseII]

Didn't realize (or recall) you actually got the saw from Mark. I now understand why he's going the extra mile(s) with it. Not many folks out there who'd go that distance.

I must attest,
Mark lives out there in extra mile territory.


Sent from my iPhone using Tapatalk Pro

 

[Jethro 2t sniffer]

Hear, hear!

If there are porting differences, of course. About as close as I could get would be to tear down a PM700 (which would have the windowed piston) and a 10-10 which should have what I now call the "port hole" piston with the complete skirt. If there is a drastic difference in cylinder porting between the two piston designs, it may well apply to Kevin's 7-10 situation as I've been theorizing.

Well everyone says there's a difference in power but I've never seen any pictures or measurements. I wonder if the points ignition is more advanced and that could explain the difference if the porting turns out to be the same. Another thought regarding Kevin's 7-10 his is the older version and is the older type really a lefthand start 6-10 and has anyone rebuilt a 6-10 with a windowed piston? I really have no clue at all just thinking.

My two 7-10s have slightly different fins around the decomp the older 1 has a larger fin and a hole for the decompression to sit through and the later one is like the 700 with that fin cut away instead. They obviously were evolving the design as time went on but why detune the same basic saw? Fuel economy? Were the 7-10s getting burnt up? You would expect power to improve from the 7-10 to the 700 especially when no EPA or noise barriers were involved.

I also read an old post of Mark's years back where he said some pm700s came with points ignition so I duno nothing seems to be concrete with these things at all. I asked Bob Johnson about it and he reckoned no difference other than the coil mounts mind you he may well of forgotten a heap of knowledge so yeah let the pondering continue.

 

[edju1958]

I had a thought about someone contacting Bob about the difficulties with Kevin's 7-10.Maybe when Mark gets back from Seattle he could confer with Bob.I'd think that between the 2 of them they'd figure it out.
Ed

 

[edju1958]

I had a thought about someone contacting Bob about the difficulties with Kevin's 7-10.Maybe when Mark gets back from Seattle he could confer with Bob.I'd think that between the 2 of them they'd figure it out.
Ed

 

[Brian Thacker]

I think Mark will fix it. Sometimes you need some time away from a project like this to regroup and put things in focus.

Brian

 

[PogoInTheWoods]

..is the older type really a lefthand start 6-10?

Interesting observation. And I would say basically, yes. But there are a few minor differences..., at least according to the piston and cylinder assembly charts I have on hand. The numbers below are from the same 1979 publication. I think it's safe to conclude that the 69412 piston became the 85239 which came in both thin and thick ring configurations with the thick ring part number difference probably reflecting the difference between a cast iron and chrome bore as there seems to have been at least two types of thick rings. I'll assume the minor skirt dimension differences are also related to the type of bore. I'm obviously speculating on a lot of this having not corroborated the chart numbers with the various hard copy IPL's floating around out there, but at least it's a reference point using the digital documentation I have on hand. Would love to have pile of the old paper manuals.

​

...never seen any pictures or measurements.

Some additional 70cc p/c and ring 'measurements' for comparison and reference. The last two are basically redundant with the PM700 added to the final one. Now that I have these consolidated it'll be easier to cross ref to IPL numbers, though it's a toss-up as to which may be more (or less) accurate of definitive.

​

 

[Maintenance supervisor]

Saved from the scrap yard?
Bar and chain for 8$ is worth that.

 

[Jethro 2t sniffer]

Interesting observation. And I would say basically, yes. But there are a few minor differences..., at least according to the piston and cylinder assembly charts I have on hand. The numbers below are from the same 1979 publication. I think it's safe to conclude that the 69412 piston became the 85239 which came in both thin and thick ring configurations with the thick ring part number difference probably reflecting the difference between a cast iron and chrome bore as there seems to have been at least two types of thick rings. I'll assume the minor skirt dimension differences are also related to the type of bore. I'm obviously speculating on a lot of this having not corroborated the chart numbers with the various hard copy IPL's floating around out there, but at least it's a reference point using the digital documentation I have on hand. Would love to have pile of the old paper manuals.

View attachment 736143​

Some additional 70cc p/c and ring 'measurements' for comparison and reference. The last two are basically redundant with the PM700 added to the final one. Now that I have these consolidated it'll be easier to cross ref to IPL numbers, though it's a toss-up as to which may be more (or less) accurate of definitive.

View attachment 736149

View attachment 736150

View attachment 736151

​

Good info there poge. Interesting to see all the oversized pistons for the iron bores

 

[Jethro 2t sniffer]

Saved from the scrap yard?View attachment 736154
Bar and chain for 8$ is worth that.

Is the nose sprocket still ok?

 

[Maintenance supervisor]

Is the nose sprocket still ok?

Yeah it rotates, the chain is so so, I'll probably soak everything in white vinegar through.
Saw must've sat outside for awhile decomp,clutch, drum and bearing are very rusty.

 

[Jethro 2t sniffer]

Yeah it rotates, the chain is so so, I'll probably soak everything in white vinegar through.
Saw must've sat outside for awhile decomp,clutch, drum and bearing are very rusty.

Nice I really like the speed tip bar I only have 1 but it's my favorite. I wonder if the modern carlton version is still the same quality

 

[Woodslasher]

Due to lack of interest on the main page, I'll move this here. Have any of y'all heard of a Mac 10-10 Lead Charger? There's one at an estate sale near me that starts Friday that has one along with some Homelites my brother's hoping to get and I want to know, is it a good buy at $100 or less? Should I jump on it or not touch it with a 10.5 foot pole? If @heimannm has any info I would appreciate it. No pics till I've visited the sale for security reasons. Here's a poor quality ebay pic of one though.

 

[joeymt33]

Due to lack of interest on the main page, I'll move this here. Have any of y'all heard of a Mac 10-10 Lead Charger? There's one at an estate sale near me that starts Friday that has one along with some Homelites my brother's hoping to get and I want to know, is it a good buy at $100 or less? Should I jump on it or not touch it with a 10.5 foot pole? If @heimannm has any info I would appreciate it. No pics till I've visited the sale for security reasons. Here's a poor quality ebay pic of one though.
View attachment 736161

Get it! Sometimes I regret selling mine to Mark.