joeymt33
I bleed YELLOW!
Hey Brian, did you receive the part I sent?
McCulloch Chain Saws
- Thread starter Bruce Hopf
- Start date
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Hey Brian, did you receive the part I sent?
BigBlue
ArboristSite Operative
OK, so I took a little time this evening to finish pulling the saw apart. It is official APART now! Took off the clutch, flywheel, oil tank cover, bolts in oil tank and outside of case. Though the flywheel did not separate very easily, I did have a 3 arm puller that was big enough and that worked.
What I found inside was encouraging. Yes, the piston looks like hell, but the cylinder is in really good shape. There is just one section of 'spots' or roughness in the area above the Q-port that is rough. Everything else looks very good. The spots I did find are not giant gouges either. I can feel them with my fingernail but I think they may be repairable.
I also did find that the rings are in place. On the bad side of the piston they are just 'welded' into the groove and that's why it didn't seem like there were any in there. Whatever found its way into the engine took a gouge out of them just as it did the piston. I assume that is what happened? An engine that overheats or runs lean would melt the aluminum but wouldn't eat into the rings, would it??
The pictures aren't great. It is hard to get a good shot into the cylinder. I may try tomorrow with my SLR (these are just with my phone).
Anyone have thoughts as to whether I'm right that this cylinder can be fixed? If it can, and I get a new piston/rings, should that get me a running saw? What other things so I have to replace with a new piston and rings? Seals, bearings, gaskets, ???
Looking into cylinder. It is deceiving because the shiny, smooth cylinder walls are reflecting all the gunk from the combustion chamber and makes it look awful. In reality the walls are smooth.
Additional pics of the piston:
Thanks!
Rob
What I found inside was encouraging. Yes, the piston looks like hell, but the cylinder is in really good shape. There is just one section of 'spots' or roughness in the area above the Q-port that is rough. Everything else looks very good. The spots I did find are not giant gouges either. I can feel them with my fingernail but I think they may be repairable.
I also did find that the rings are in place. On the bad side of the piston they are just 'welded' into the groove and that's why it didn't seem like there were any in there. Whatever found its way into the engine took a gouge out of them just as it did the piston. I assume that is what happened? An engine that overheats or runs lean would melt the aluminum but wouldn't eat into the rings, would it??
The pictures aren't great. It is hard to get a good shot into the cylinder. I may try tomorrow with my SLR (these are just with my phone).
Anyone have thoughts as to whether I'm right that this cylinder can be fixed? If it can, and I get a new piston/rings, should that get me a running saw? What other things so I have to replace with a new piston and rings? Seals, bearings, gaskets, ???
Looking into cylinder. It is deceiving because the shiny, smooth cylinder walls are reflecting all the gunk from the combustion chamber and makes it look awful. In reality the walls are smooth.
Additional pics of the piston:
Thanks!
Rob
BigBlue
ArboristSite Operative
Here are some better pics. I guess there are a few other pits and a scrape. None are deep though.
Rob
Rob
Brian, I don't have a clue. MAC are tough.
Rob, I'm still thinking a needle bearing- possibly from the wrist pin. Looks like it was run with Dino oil instead of a synthetic or it has burned a lot of bar oil.
Ron
Piston is shot but I cannot tell about the cylinder. If this is pitting then the cylinder will need to be replated. If this is aluminum transfer from the piston it can be removed in various ways. I use very fine crocious cloth to remove. Some use muriatic acid. I have never used this but many have had good success. Either method you use, you just need to take your time and be careful. That cylinder is chrome plating over aluminium and if their is any opening in the chrome plating it will burn threw the cylinder wall.
Brian
Brian
Your pic came threw as I was typing. My eyesight is failing now days but it looks like I see gouges that are threw the chrome plating. If so it will need replated.
Brian
Brian
BigBlue
ArboristSite Operative
I think I'll try to find someone that does cylinder repair and see what they say about it. I don't think I want to try much on my own.
Rob
Rob
McCulloch offered a Service Bulletin recommending running 32:1 in the 82 cc saws since they were such high performance models.
Aluminum transfer can be removed with scotch brite pads on an arbor operated by a drill or a Foredom if you have one.
Mark
Aluminum transfer can be removed with scotch brite pads on an arbor operated by a drill or a Foredom if you have one.
Mark
Rob I use US Chrome to replate my cylinders. If you want you can send it to me and I can look at it and see if it can be salvaged. If not I can have it replated for you. I have an A cylinder right now on the shelve that I just got back from them and they done a wonderful job. Just not had the time to swap the cylinder out with the B cylinder I have on it now that is not bad but a little loose. I am going to send the old one to be replated after I find the time to swap the cylinders.
Brian
Brian
BigBlue
ArboristSite Operative
So what would something like that cost, potentially, to have it replated?
Thanks,
Rob
Around 190.00 to around 210.00
Brian
Brian
BigBlue
ArboristSite Operative
Yes I did thank you! Haven't had time to mess with yet. I will this weekend. Part time saw repair, part janitor, and full time farm hand. Lol
That cylinder really has me stumped. It is not a PM8200, the PM8200 has a six bolt crankcase where the other 82 cc models are all eight bolts.
I can't figure out what the clean out port would be used for since it does not have a pop up style compression release; see out the attached .PDF file. The port appears to go through the cylinder wall if you look at his photo inside the cylinder.
Looks like maybe it was for a Double Eagle 80 but there is no compression release above the muffler. It does appear in one of the photos that is has the "Q" port in the exhaust.
Mark
I can't figure out what the clean out port would be used for since it does not have a pop up style compression release; see out the attached .PDF file. The port appears to go through the cylinder wall if you look at his photo inside the cylinder.
Looks like maybe it was for a Double Eagle 80 but there is no compression release above the muffler. It does appear in one of the photos that is has the "Q" port in the exhaust.
Mark
I have thought about buying the one on ebay and putting it on the shelve myself. It being new would be the direction I would go if you cylinder is bad.
Brian
Brian
BigBlue
ArboristSite Operative
Early next week I'm going to take the jug to a local cylinder head repair place around here to be looked at. If he can get by with just honing it or some minor refurbishing, will I still be able to use a stock piston or will I have to seek out a custom sized piston? How hard would that be?
Thanks,
Rob
Thanks,
Rob
I would not hone that chrome. Fine sandpaper is the most I would use on it. That chrome is very thin and if you remove much of it at all you will be into the aluminium. It is hard to tell by the pictures but what is on there could me just aluminium from the piston and it can be sanded off. I would try that but like I said it is hard to tell by the pictures but I thought I saw a place that looked to me like the chrome was penetrated threw. It was not a very big spot but enough to burn threw the cylinder wall.
Brian
Brian
I've never heard of a cylinder (on a saw not used for racing) burning through in area lacking plating..., especially below the ports. Additional flaking occurring, possibly (but not necessarily imminent, either). Bare aluminum cylinders with plated pistons were common not that many years ago. I may be all wet, but have never worried about small areas of missing plating.
I would not use acid to clean up any cylinder with questionable plating or aluminum exposure. It will eat any exposed aluminum and destroy an otherwise perfectly salvageable cylinder that may only have some incidental streaking or gouges along with the typical aluminum x-fer that can be easily removed by any number of simple methods. Traditional honing should be avoided as it is too aggressive. 220 grit paper would be a good start to see what you can remove easily just using a drill with a split mandrel for the paper. You may be surprised at how well it cleans up while also putting a much more positive (and economical!) spin on the matter.
I would not use acid to clean up any cylinder with questionable plating or aluminum exposure. It will eat any exposed aluminum and destroy an otherwise perfectly salvageable cylinder that may only have some incidental streaking or gouges along with the typical aluminum x-fer that can be easily removed by any number of simple methods. Traditional honing should be avoided as it is too aggressive. 220 grit paper would be a good start to see what you can remove easily just using a drill with a split mandrel for the paper. You may be surprised at how well it cleans up while also putting a much more positive (and economical!) spin on the matter.
BigBlue
ArboristSite Operative
Thanks for the tips. So, just a small mandrel like this with a flap of sandpaper inserted into it and then work in/out of the cylinder a bit? Or something else?
Rob
