2/ Addiction
New Member
Hi Guys,
Great site you have going here, lots of good advice and help for the newbies like myself.
I just recently discovered chainsaws and love it, small 2/ engines screaming away, takes me back to my youth running 2/ motorcycles, RD250/350LC etc. US designation was RZ250/350LC I think? Anyway satisfies my ears and the big piles of firewood come in handy as well.
About 15 years ago I bought a MacCat 839 at auction very cheaply; absolutely mint no signs of wear whatsoever. I used it the once to “burn” my way through a 5” stick and when it ran out of fuel I was glad and put it away into the attic for the next 15 years. My thinking at the time was I didn’t know how to sharpen the chain, had no PPE and no idea at all what I was doing with it, in short I figured I was an accident waiting to happen and it was probably best that the thing was put out of immediate reach.
Fast forward 15 years and circumstances changed, with the high winds last year and trees down all over the place, my work had a number of issues with access roads to sites being blocked, we had only the one guy with a chainsaw ticket and he was working non-stop for three days clearing fallen timber. My boss decided that he wanted another four people qualified on chainsaws for the next time and I was asked if I wanted to do the course, my initial reaction was No (never volunteer!) and about fifteen to thirty seconds later I changed my mind to Yes! Well that course grew arms and legs due to insurances and liability, so to get approved for clearing windfall and taking off root-balls we have to do, chainsaw maintenance, small tree felling, crosscutting and clearing, medium tree felling, root-balls on single windfall and it looks like we have another course to do for multiple windfall. It’s been great fun, but I can only say that the guys working in the felling industry really earn their money, it’s hard work to be doing day in, day out.
Anyways as it’s my first post I thought a little intro was in order, so hope I didn’t bore you all. My problem is that the MacCat 839 snapped a bar stud when being tightened! Honestly I wasn’t going mad with the wrench and figure that the metal used is substandard or at least of a lesser quality than I thought. I contacted the UK dealer who advised that the part (stud) is obsolete and he couldn’t help, now that maybe the case but I am sure that MacCulloch didn’t change the part that much when revamping their product line and am hoping that someone can advise what modern part number can be tied back to the old 839 stud part number so I can get the little bugger back in action again. It’s not a great saw but I like it (a lot) and have dropped a lot of trees on the mark with it, so some help would be appreciated, I could also do with a work shop manual for it.
My second problem is somewhat different but the same, another obsolete part if I understand correctly. Figuring that more is better, especially when crosscutting 3’ beech for fire wood I bought a Husqvarna 266XP off of Ebay, sold as in good working order. To be fair the saw start easily, runs well, ticks over nicely and restarts with no issues. Compression felt a bit low though and on testing was found to be 70psi, with a little oil in the chamber compression tested at 100psi, still not brilliant even should my tester be reading a little low. Got out the borescope and checked the cylinder and could see some evidence of scorching and what looked like alloy on the cylinder walls, so pulled off the exhaust and carb, scoring could be seen on the intake and exhaust side of the piston. Not really a problem I figured on rebuilding the saw over the next twelve months anyway, maybe porting it a little and doing some other mods to improve performance. I hadn’t figured on the fact that replacement cylinders for the 266 saw are expensive and hard to come by, I had figured with a production run of over twenty years a number of suppliers would be producing components for it.
Anyway I have removed the stuck alloy from the cylinder with sulphuric acid and there are only two small scores of note on the cylinder walls, these appear to be both below the bottom of the exhaust port, so hopefully will not have to much effect on the rebuild. My ball hone and full gasket set have arrived and am presently waiting on the replacement piston coming, so thanks to those guys who have posted on how to remove alloy smearing etc. With the clean up and a new ring only, compression has now come up to 100psi so am hopeful that the hone and new piston will give another increase.
The real problem for me is that the saw is actually marked on chassis plate as a 266SE, the covers have the XP stickers and the present cylinder is of the closed port variety, so would appear that it may have been converted at some point in it life, I am still unsure on the crank type at this point but will investigate closer when I get around to changing the crank seals. The saw has the old metal brake handle and on inspecting the brake band it can clearly be seen to be knife edged (thin) on the bottom and does not have much life left in it so needs replaced, the sooner the better.
Does anyone know what part number the band is for the older style brake band?
Do they know where I can source one? I really want to keep the existing configuration but if pushed I may have to replace the side casing and brake, if I understand correctly this means also changing or modifying the exhaust outlet, all stuff I do not really want to do at this point at least. But if necessary what side casing would be best to replace the existing one with?
I’m also looking for a workshop manual for the 266SE/266XP if anyone can help?
Any help would be appreciated, chainsaws are great fun and dropping trees is fun as well, especially when getting up into the 30” now.
Great site you have going here, lots of good advice and help for the newbies like myself.
I just recently discovered chainsaws and love it, small 2/ engines screaming away, takes me back to my youth running 2/ motorcycles, RD250/350LC etc. US designation was RZ250/350LC I think? Anyway satisfies my ears and the big piles of firewood come in handy as well.
About 15 years ago I bought a MacCat 839 at auction very cheaply; absolutely mint no signs of wear whatsoever. I used it the once to “burn” my way through a 5” stick and when it ran out of fuel I was glad and put it away into the attic for the next 15 years. My thinking at the time was I didn’t know how to sharpen the chain, had no PPE and no idea at all what I was doing with it, in short I figured I was an accident waiting to happen and it was probably best that the thing was put out of immediate reach.
Fast forward 15 years and circumstances changed, with the high winds last year and trees down all over the place, my work had a number of issues with access roads to sites being blocked, we had only the one guy with a chainsaw ticket and he was working non-stop for three days clearing fallen timber. My boss decided that he wanted another four people qualified on chainsaws for the next time and I was asked if I wanted to do the course, my initial reaction was No (never volunteer!) and about fifteen to thirty seconds later I changed my mind to Yes! Well that course grew arms and legs due to insurances and liability, so to get approved for clearing windfall and taking off root-balls we have to do, chainsaw maintenance, small tree felling, crosscutting and clearing, medium tree felling, root-balls on single windfall and it looks like we have another course to do for multiple windfall. It’s been great fun, but I can only say that the guys working in the felling industry really earn their money, it’s hard work to be doing day in, day out.
Anyways as it’s my first post I thought a little intro was in order, so hope I didn’t bore you all. My problem is that the MacCat 839 snapped a bar stud when being tightened! Honestly I wasn’t going mad with the wrench and figure that the metal used is substandard or at least of a lesser quality than I thought. I contacted the UK dealer who advised that the part (stud) is obsolete and he couldn’t help, now that maybe the case but I am sure that MacCulloch didn’t change the part that much when revamping their product line and am hoping that someone can advise what modern part number can be tied back to the old 839 stud part number so I can get the little bugger back in action again. It’s not a great saw but I like it (a lot) and have dropped a lot of trees on the mark with it, so some help would be appreciated, I could also do with a work shop manual for it.
My second problem is somewhat different but the same, another obsolete part if I understand correctly. Figuring that more is better, especially when crosscutting 3’ beech for fire wood I bought a Husqvarna 266XP off of Ebay, sold as in good working order. To be fair the saw start easily, runs well, ticks over nicely and restarts with no issues. Compression felt a bit low though and on testing was found to be 70psi, with a little oil in the chamber compression tested at 100psi, still not brilliant even should my tester be reading a little low. Got out the borescope and checked the cylinder and could see some evidence of scorching and what looked like alloy on the cylinder walls, so pulled off the exhaust and carb, scoring could be seen on the intake and exhaust side of the piston. Not really a problem I figured on rebuilding the saw over the next twelve months anyway, maybe porting it a little and doing some other mods to improve performance. I hadn’t figured on the fact that replacement cylinders for the 266 saw are expensive and hard to come by, I had figured with a production run of over twenty years a number of suppliers would be producing components for it.
Anyway I have removed the stuck alloy from the cylinder with sulphuric acid and there are only two small scores of note on the cylinder walls, these appear to be both below the bottom of the exhaust port, so hopefully will not have to much effect on the rebuild. My ball hone and full gasket set have arrived and am presently waiting on the replacement piston coming, so thanks to those guys who have posted on how to remove alloy smearing etc. With the clean up and a new ring only, compression has now come up to 100psi so am hopeful that the hone and new piston will give another increase.
The real problem for me is that the saw is actually marked on chassis plate as a 266SE, the covers have the XP stickers and the present cylinder is of the closed port variety, so would appear that it may have been converted at some point in it life, I am still unsure on the crank type at this point but will investigate closer when I get around to changing the crank seals. The saw has the old metal brake handle and on inspecting the brake band it can clearly be seen to be knife edged (thin) on the bottom and does not have much life left in it so needs replaced, the sooner the better.
Does anyone know what part number the band is for the older style brake band?
Do they know where I can source one? I really want to keep the existing configuration but if pushed I may have to replace the side casing and brake, if I understand correctly this means also changing or modifying the exhaust outlet, all stuff I do not really want to do at this point at least. But if necessary what side casing would be best to replace the existing one with?
I’m also looking for a workshop manual for the 266SE/266XP if anyone can help?
Any help would be appreciated, chainsaws are great fun and dropping trees is fun as well, especially when getting up into the 30” now.