McCulloch Chain Saws

[vinnywv]

So the 7-10 big open transfers vs 7-10 bridged transfers and the 700 cylinders with bridges we are still assuming the porting difference is that transfer shape. It really would be good get them timed by someone. I'd like to know if the points 7-10 bridged transfer is the same as the electronic bridged 700. They look the same but perhaps the big "difference" between 7-10 and 700 is more down to timing as apposed to the transfer.

If it turns out no and they are infact same same then grab a dremel and remove that bridge. Was also thinking could hog out the 3 finger cast transfer into a big open also.

Perhaps mac put the bridge in for engine life.

The interesting thing is the more desirable bridged 82cc cylinder vs the open older type is the opposite of what we see in the 70s. Was chatting with Vinny (after the dishes) and he mentioned how the later feels like it has more compression. Perhaps the 70s power differences is really from something else and the transfers are not it

Cmon guys!!
Bwahahahahahahaha

 

[vinnywv]

True to jethros post, i have a sp81 with an open transfer that i recently put together. And a sp81 thats bridged. They have very different compression when pulled slowly. The open transfer has noticeably less than the bridged. They both run like mad and cut great but they are different.

 

[edju1958]

Hi guys,just wondering if anyone here can identify this older Mac.I can get more pics if needed.
Ed

 

[ML12]

Hi guys,just wondering if anyone here can identify this older Mac.I can get more pics if needed.
EdView attachment 806214

Looks like a 250 or other front tank variant, given the full wrap i'd say one of the larger or better ported ones. If you can get a photo of the underside of the block, there will be model #s stamped in.

 

[Walter Glover]

Vinny, in theory there should be no compression difference made by transfer port design. Compression only occurs when the rings seal above the ports and the volume is reduced as the piston moves up. The 80s have serious compression for sure. I have an SP80 with oem cylinder that cleaned up ok running a chainswr piston and rings. If it fires enough to pop the decomp the next pull rips the handle out of the hand with very sore fingers as a result!
Runs like a boss for sure lol

 

[heimannm]

Ed - If that is the original wrap bar and long black AF cover then the saw is most likely a 1-51, 1-52, or 1-53. There will be a model number stamped on the bottom of the crankcase.



The 1-52 and 1-53 models are 87 cc and pretty strong when they are in good shape. They have basically no anti-vibe provision.

Mark

 

[edju1958]

The saw I had a pic of is for sale on Feebay & is the same seller that 2broke got his 5-10 from.Some people think sdhe's a good seller,I don't think so because if I ask any details about a saw I never get a reply.I'm not the only person this happens to either.I wouldn't buy that saw at that price of $149 + $48 shipping + taxes.Too much IMHO.
Ed

 

[edju1958]

I'm just waiting on parts from Bob Johnson to get the DE80 going & the 6-10 too.As soon as the saws start to come together I'll post some pics.
Ed

 

[2broke2ride]

The saw I had a pic of is for sale on Feebay & is the same seller that 2broke got his 5-10 from.Some people think sdhe's a good seller,I don't think so because if I ask any details about a saw I never get a reply.I'm not the only person this happens to either.I wouldn't buy that saw at that price of $149 + $48 shipping + taxes.Too much IMHO.
Ed

Most of her sales are buy now or best offer. I beat her down almost half on the 5-10. She says right in her adds, she doesnt know anything about the saws.
Shipping was slow and packing was poor.

Sent from my SM-G950U using Tapatalk

 

[vinnywv]

Vinny, in theory there should be no compression difference made by transfer port design. Compression only occurs when the rings seal above the ports and the volume is reduced as the piston moves up. The 80s have serious compression for sure. I have an SP80 with oem cylinder that cleaned up ok running a chainswr piston and rings. If it fires enough to pop the decomp the next pull rips the handle out of the hand with very sore fingers as a result!
Runs like a boss for sure lol

I agree and do understand your reply. Its seems an oddity on them for sure. I was just curious, not a concern by no means at all. With decomp out it hurts. I dont know. Thanks though....maybe im just over thinking it.

 

[Jethro 2t sniffer]

I agree and do understand your reply. Its seems an oddity on them for sure. I was just curious, not a concern by no means at all. With decomp out it hurts. I dont know. Thanks though....maybe im just over thinking it.

It could be something else like squish or combustion chamber shape or exhaust port height or a combination. Will never know until someone measures it all up and that's well above my hourly rate lol and I only have two 82cc saws

 

[PogoInTheWoods]

Or could just be the difference in rings.

 

[Jethro 2t sniffer]

Or could just be the difference in rings.

Well yeah true. Do the Mac rings have the end gaps set? I have bought 1 set for a 10-10 and they are way too long so assumed they were in the wrong box.

The two 82cc saws feel like no end gap at all or a very small 1. I've got a 4000 I set to factory end gaps and it's like a gaping hole in comparison

 

[vinnywv]

Yea jethro, i dont care that much to map out a chainsaw or to go into the depths as the 7-10....lol.
I was just curious. Many factors involved.....anyone got toilet paper??? Lets talk about this insanity awhile. Apparently now we are not prepared for the zombie apocolypse like we thought with all our saws. Instead the poopocalypse has hit first and our saws are useless for that issue...hahahahahahahaha

 

[Jethro 2t sniffer]

It is quite a laugh really the whole dunny roll thing. Just madness absolute madness all drivin by the mighty Facebook and others.

I would like to port a mac and be interesting to see what bell hopper does to Aaron's 81. 1day I'll get a degree wheel or make 1

 

[Walter Glover]

Rings must be gapped for the cylinder they will run in. Use the piston to push them into bore truly square then measure. Grind off ever so little at a go until the correct gap is measured. You will need the spec for your saw

 

[heimannm]

Jethro - just copy the file, scale it to fit a CD and attach it with some spray adhesive.



Mark

 

[PogoInTheWoods]

The larger you can scale it, the easier (and more accurate) it will be to read.

 

[Jethro 2t sniffer]

Jethro - just copy the file, scale it to fit a CD and attach it with some spray adhesive.

View attachment 806289

Mark

Man that's awesome cheers Mark

Rings must be gapped for the cylinder they will run in. Use the piston to push them into bore truly square then measure. Grind off ever so little at a go until the correct gap is measured. You will need the spec for your saw

Thanks Walter. What ever happened with that pro mac 60?

 

[Walter Glover]

Jethro I am waiting on time, inspiration, intrepidation and motivation!
Have the materials and tools but scared spotless to cut metal haha. Might be doing it aprilish when the weather breaks but too wet to work outside