McCulloch Chain Saws

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Any ideas what's going on here? Is it toast?
Probably just wear, but still needs to be inspected carefully and corrected. That saw should be completely torn down and rebuilt leaving no stone unturned..., especially if any debris got into the crankcase while attempting to clean around the intake or while removing the carb. You're in good hands here to receive the most knowledgeable and experienced Mac advice and assistance available anywhere.

Go forward with confidence and don't hesitate to ask for help when you have more questions. That IPL will be your new best friend as you become more involved with disassembly and parts identification as the mission continues..., "should you choose to accept it". LOL (Old Mission Impossible line...)

Whichever way you go, good luck with it.
 
Well, got a few minutes to pull the muffler on the 7-10. Doesn't look good for the home team. How do you like your steak, well or burnt?
G5feeRn.jpg
 
Well, got a few minutes to pull the muffler on the 7-10. Doesn't look good for the home team. How do you like your steak, well or burnt?
G5feeRn.jpg

Poor old saw got choked up bad with carbon then started to chew on it :( cylinder may still be ok yet though. Are ya going to keep pulling it down? Pistons are still readily available
 
A piston will wear away getting looser in the bore it starts to hurt the bore eventually. Piston slap
I had a feeling it was something like this. Is it safe to assume that the cylinder is likely wrecked if the previous owner ran it like that for who knows how long?
Go forward with confidence and don't hesitate to ask for help when you have more questions.
Believe me, I'm sure there will be many more questions coming from me in the future. :laugh:
I really do appreciate all the helpful advice I've been receiving here. I feel like I've come a long way in a few months from never having done anything with a saw besides cutting and putting in fuel and bar oil, to now having the things split in half to do some serious work.

Anyway, I'm putting the G-70 on the backburner for now, since I still have that SP81 torn apart and I don't trust myself to tear apart a second saw at the same time and not lose a vital screw or bolt lol.
I finished the tank swap and put everything back together for now so I don't misplace anything. I think this is a really cool looking saw with that all-yellow 10 series appearance but with the gear case and those big dogs stuck on the side. Looking forward to returning to this one.
TankSwap1.jpg
TankSwap2.jpg
Speaking of the SP81, here's the last bit of progress that I did before I got the G-70. Still needs a little more but I think the piston is cleaning up really nice. They look fine to me, but should I go ahead and get new rings for this anyway?
Also, any tips on cleaning cylinders? Kind of difficult to get down in there.
CleanPiston.jpg
 
Poor old saw got choked up bad with carbon then started to chew on it :( cylinder may still be ok yet though. Are ya going to keep pulling it down? Pistons are still readily available
Yes. Funny there was still a service tag on it and the problem the customer said it had was weak spark. When I pulled the plug I thought it had great spark. I saw two pistons on Ebay for $100 bucks. Does the greek guy make a piston for these. I got one of his for a Super 1050 and it was a nice piston. Any other sources?
 
Yes. Funny there was still a service tag on it and the problem the customer said it had was weak spark. When I pulled the plug I thought it had great spark. I saw two pistons on Ebay for $100 bucks. Does the greek guy make a piston for these. I got one of his for a Super 1050 and it was a nice piston. Any other sources?

Old mate Bob or ebay. I got an LRB at home that "seems" nice. Vinny has had good luck with an LRB. Kevin machayes also has a 700 running an LRB.
 
Anyway, I'm putting the G-70 on the backburner for now, since I still have that SP81 torn apart and I don't trust myself to tear apart a second saw at the same time and not lose a vital screw or bolt lol.
When I disassemble something I get a cardboard box (pizza boxes are ideal) and punch holes in it to stick the bolts in. I keep them in groups and draw a shape around the group that roughly corresponds to the part being taken off (eg: a square with a bolt in each corner for the starter). I do this in the order of disassembly, usually working left to right along the box. This helps when you reassemble and also if you keep the box it helps for next time (provided you did everything in the right order the first time). Plus you don't lose anything.

It's just what I do. Probably some OCD tendancies there...
 
Ive had luck with 2 so far. Sp81 and a sp70 piston from lrb. Got one off ebay the other was actually from bob johnson. I did have to reuse wrist pins in both from the original piston as stated before from others. But so far the piston itself has worked just fine.
 
Tim - you'd better locate the top screw for the starter, hate to see it show up inside of the flywheel housing.

I decided to go with the JB patch for the clutch cover on the junk yard dog 125, sort of keeping with the theme on this project. I took some wire screen material and cut and formed it to the approximate correct shape, applied some JB, press the wire in, apply some additional JB, use the heat gun to get everything to flow together nicely and I think I will have a satisfactory repair.

20201214_175207.jpg

Mark
 
Tim - you'd better locate the top screw for the starter, hate to see it show up inside of the flywheel housing.



Mark

Thanks Mark. I never noticed it was missing. I suspect it's been gone for awhile. The starter needs come apart as it's squawking when the cord is released so I'll add a bolt then.

Is there any chance the 4 shoe clutch from a yellow top Super 250 will fit that 125 you're fixing up?
 
I had a feeling it was something like this. Is it safe to assume that the cylinder is likely wrecked if the previous owner ran it like that for who knows how long?

Believe me, I'm sure there will be many more questions coming from me in the future. :laugh:
I really do appreciate all the helpful advice I've been receiving here. I feel like I've come a long way in a few months from never having done anything with a saw besides cutting and putting in fuel and bar oil, to now having the things split in half to do some serious work.

Anyway, I'm putting the G-70 on the backburner for now, since I still have that SP81 torn apart and I don't trust myself to tear apart a second saw at the same time and not lose a vital screw or bolt lol.
I finished the tank swap and put everything back together for now so I don't misplace anything. I think this is a really cool looking saw with that all-yellow 10 series appearance but with the gear case and those big dogs stuck on the side. Looking forward to returning to this one.
View attachment 874041
View attachment 874042
Speaking of the SP81, here's the last bit of progress that I did before I got the G-70. Still needs a little more but I think the piston is cleaning up really nice. They look fine to me, but should I go ahead and get new rings for this anyway?
Also, any tips on cleaning cylinders? Kind of difficult to get down in there.
View attachment 874043

Check the gap of the rings n see what ya got.

The g70 bore probably ok it will be good to get her running anyway. I got a 7-10 with a few good grooves and lots of missing chrome and its still running far to well to call it parts yet. Probably pointless doing the rings/piston though it might just tear up whats left of the chrome
 

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