McCulloch Chain Saws

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Mark, thanks for the info, seems like Mcculloch made a lot of variations lol. I think that mine has the thick rings on it, and I was going to pull it apart to check all the bearings and replace crank seals and piston rings. I will make note of the porting and compare it to the D45 I also have that has the same (I think) cylinder casting that I will also be ripping in to sooner than later I hope.
 
Well,today I go in for another knuckle replacement,this time on my left hand & it can't be any too soon.This is the 3rd replacement,soon I'll run out of knuckles,Lol.Just when I was getting back to wrenching on saws again from the last surgery back in Aug.Oh well,time for more educational reading & another mini vacation.Although the last time I had a knuckle replacement the end of April,I continued to work on saws.The occupational therapist wanted to know if I was using my right hand to start the saws.I replied "no",then she wanted to know how I was starting them.I said it all depended on if they were RH start or LH start.She looked at me with a puzzled look.I had to have my son video me starting a saw with my left hand & when I showed it to her she then believed me.A man has to be innovative at times.
 
I recently loaned a 610 & a 650 to a good friend of mine & he was really impressed with the 650.The 610 ran for a bit & then died & he couldn't get it restarted.The 650 is hard starting & he said he did some reading up on the 600 series saws & told me that it was a common problem for the saws to have a vapor lock problem because the fuel tank is so close to the engine.I've never heard of this or experienced it.He said the saw will start cold without a problem,but when it's hot/warm is when it's difficult to start.I've never had either this particular 610 or 650 out cutting.
 
Ok so I had some time to work on my 1-75 project saw. The fuel line was roughted over the top(like a 10-10). It has a built in line in the bottom the IPC shows this one. A bolt has been run in inside the tank. This may have been modeled for vapor lock?
 

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The 1-75/85 would have used the lower fuel fitting with a tight, 90 degree fuel line to the carburetor. The fuel filter/wick was a large felt pad in the bottom of the tank channeled to that oval bowl in the bottom of the tank.

The 1-76/86 models used the style of tank top on your saw currently, with a fitting though the tank and a flexible fuel line on either side, with a weighted fuel filter on the line in the tank.

I would say someone has replaced the tank top on your 1-75 with the tank top off a 1-76/86. While they were doing that they chose the alternate fuel line option. The large wick/filter in the tank has a tremendous amount of filter area, and the felt will absorb any water in the fuel, but servicing that filter means disassembling the fuel tank. I'll guess it was done as a matter of convenience for future service.

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Mark
 
Last Saturday we had a good Mac day with my SP125 taking down and bucking a large oak stem, and the 7-10 noodling the rounds into more manageable size pieces.

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We did not get it all split and hauled out on Saturday, so I had to finish on Monday. It took some effort to get those blocks maneuvered into the spllitter.

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Mark
 
Last Saturday we had a good Mac day with my SP125 taking down and bucking a large oak stem, and the 7-10 noodling the rounds into more manageable size pieces.

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We did not get it all split and hauled out on Saturday, so I had to finish on Monday. It took some effort to get those blocks maneuvered into the spllitter.

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Mark
Nice work Mark, that tree had some nice firewood in it! What size bar did you use on the 7-10? I picked one up a few months ago that has a 16" bar on it, was thinking about picking up a 24" for helping my dad cut some of his oak in northern Michigan.
 
The bar on the SP125 is 42", just enough for the bigger rounds. The bar on the 7-10 is 20", I have run a 24" on other 70cc McCulloch models and they work well. I like the 20" on this one since I use it mostly for working up the larger limbs.

I will end up with a couple of running PM700's from these boxes that were dropped off the day we were working on the big pin oak.

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I was able to salvage two short blocks that have around 130 PSI compression. I don't expect them to be able to compete with the 7-10 but I will outfit them with 20" bars and I'm sure they will be fine.

Mark
 
Looks like Christmas came early for you (in a dirty, yellow sort of way). I haven't checked the compression of my 7-10 yet, but it is really good, can't pull it without decomp - the saw wasn't used very much, that's for sure. Thanks for the info on bar size, I was thinking about running a longer bar to save my back.
 

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Looks like Christmas came early for you (in a dirty, yellow sort of way). I haven't checked the compression of my 7-10 yet, but it is really good, can't pull it without decomp - the saw wasn't used very much, that's for sure. Thanks for the info on bar size, I was thinking about running a longer bar to save my back.
See 700s in that kinda condition but 7-10s not so much. Dang nice saw 😍
 
I like 20" bars on these light weight Macs. They can handle a 24" bar, but then they aren't as nice to handle themselves (unless you are always cutting small wood at ground level). I run 18-20" on all of my 54cc-70cc McCullochs. 22-24" on the SP81 is good (CP70 is similar because it is a big lump compared to a 7-10). I like 24"+ on my large frame front tank McCullochs. Balances them better and they look funny with 18" bars.
 
I put together this PM700 mostly from the boxes dropped off above . New rings, seals, PTO side bearing, muffler from NOS parts, fuel tank gasket (Viton), brake parts, gaskets, carburetor kit, some used parts, and the modified PM style clutch cover. The cover was pretty well busted up so I cut the back end off and smoothed it out a bit. Runs and cuts pretty nicely. I'm not sure if it would hang with my 7-10 but it's not bad with the 20" bar buried in my oak test log.

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One of my earlier 3D printed sawdust screens.

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Mark
 
That's a pretty mean looking saw Mark! I have a 10-10A that I picked up for a few bucks that has no compression, was planning on pulling it apart as a winter project, hopefully just needs rings. Saw is in pretty good shape otherwise. Any advice on things to look out for?
 
The rings may just be stuck in the grooves. Ive been lucky like that before. If its shot nearly any 54cc engine will fit.in there. Points vs elec coil mount is about all the difference. There are always exceptions but 1-10, 2-10, 3-10 l, 10-10 will all work. Sneak a 57cc in it or better yet a 70cc engine. Now youll have a runner. Lol
 
When I take one down, I normally put in new crankshaft seals and the PTO side bearing while I'm in there. I have found in many cases the piston is worn to the point that rings alone don't always bring the compression back up. I'm not a fan of LRB pistons but you may not have another choice if you need to replace the piston, just don't use their wrist pin as they fall out. NOS pistons are becoming more precious these days...

Mark
 

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