Center drive Sprocket replacement

[361filer]

I have a PN5200 which I mistakenly believed to be a stihl ms361 when the swine handed it over. He had the markings of the 361 covering this chinese/others markings.
Anyway, I need to change the sprocket, and its a center drive instead of the easy circlip type, and I haven't a clue how to get it off. Any chance someone could help me out? Is it possible to change it myself, maybe I need to get an extra tool, or use a hammer ..? Yes I'd like to break it but presently that is not economically feasible.

Thank you ever so much in advance for any and all help/comments.

[beenthere]

Welcome to the forum.

Hard to figure out just what your situation is. Signed in for help on MS361. Then announce that it was something else, and not an MS361.

Can you explain that, so we understand what is going on?  Without the "swine" flavor please. 

Maybe someone can then help figure out what is happening.

[windthrown]

Lemme get this straight... you bought a chinese knock-off saw gussied up and badged as a 361? And you say that this "saw" has an outboard clutch on it? All I can say is good luck with that. Lipstick on a pig. A real 361 has an inboard clutch, as do most Stihl saws. Short of going after the guy with a AR-15 or your knock-off saw revving at max RPM throwing the chain at him, I do not have any advice. I have lots of experience with real 361s should you get your hands on one though.

Looking online, these "greenstar" PN5200 POS Chinese chainsaws seem to have several flavors, and made to look like the more popular Husky, Shindaiwa, Redmax and Stihs saws. Max RPM is 7500... 51cc.  Ooops, make that 49cc. No... wait a minute, 5200cc??? There seems to be a whole series of these saws, knock-offs of the knock offs? BS chainsaws, INC.

My advice, toss that saw. No point in fixing it. The tolerances on these saws is a joke, and they rev so low that they do not make enough power to do any real work. They are also dangerous, and apt to fly apart or break when being used. Hard to say which one you have, and where to get parts for them.

Tsing Tao Chainsaw!
Saw last long time!
No drippy bar!
Saw cheap cheap!
Saw run good!
You like saw!
Saw last long time!

[Al_Smith]

Well Chinese or not the clutch itself will be left hand threads .Block the piston using a piece of starter rope through the spark plug .Then use a drift of some kind,like a brass rod and drive it loose .Righty loosey,lefty tighty .

After you get it repaired spend some time researching chainsaws on the net so don't get a royal screwin the next time you buy one .

[sablatnic]

I would use the starter cord too, but take care not to get the cord out in the ports, or you could ruin the piston. Look down the plug hole, turn the clutch until the piston just close the exhaust port, and then stuff as much cord down the hole as possible. Then use the hammer and the drift, unless the clutch can be turned with a wrench. Good luck. The 5200 does look quite a lot like a Stihl. Good trick with the stickers. Will remember it.

[361filer]

Sorry about that. The guy is a swine, but he's a local character/friend of ours. I just have to take this with a pinch of salt. It is my fault for accepting his offer. It is mine now, and I cannot give it back without making my life a misery and all those around me, realistically. So all the flavour is rationalised out hopefully.

I'm used to the clutch being a pedal or grip that is pushed or pulled, and don't understand about stuffing stuff in the piston, or using a drift, sorry.

With this saw I have downed a trunk of diameter 50cm, and had started slicing it up for shelves, when the chain came off a couple of times. Now I have a new chain, and I want to put on a new sprocket, which is held on by a mushroom shaped 'thing' which must have a way of coming off. Do you know what I mean? The mushroom head is flat and has a star shaped thing holding in a spring .. maybe you need a picture.

Ideally I will get a stihl 361 or husky 367, or similar, but till then I'm stuck with this.

[Cut4fun]

How about a pic of this 361 or whatever it is 

[windthrown]

The mushroom thing is an outboard clutch and brake drum in one. Chainsaw cluthes are centrifugal spring activated. Meaning that at low speeds, the springs pull the clutches toward the center of the crankshaft spindle, and hence they disengage from the drum and drive sprocket which is typically part of the drum. At higher speeds the clutches fly outward and engage the drum, and that drives the sprocket and chain. The outer part of the mushroom is typically surrounded by the brake band, which when activated stops the drum and sprocket from spinning.

Outboard clutches are common on Husky saws, and probably what the Chinese used to copy their saw design from. To remove the outboard clutch, or mushroom as you describe it, you have to freeze the crankshaft spindle in order to use a ratchet to remove the clutch mechanism. To freeze the crank, you typically remove the spark plug and put in an engine piston stop (a threaded stud, or a small lever with a bulb of metal on the end that you stick inside the spark plug hole) or you use some starter rope or oil cloth that you shove into the spark plug hole to stop the piston form moving. The clutch is attached to the crankshaft like a nut is on a bolt; with threads. The bolt is the crank spindle, and the clutch is the nut. They are typically reverse threaded though, so that they stay tight when the saw is run, rather than loose. Many outboard clutches require a special hex head with extended segmented slots that reach into the clutch so that you can remove it. I had to grind down a spark plug wrench to design one that would remove the outboard clutches on my Echo saws. Then its just a matter of removing the threaded clutch, and pulling off the drum/sprocket.

Now, all this can be averted if you buy a saw with an inboard clutch. Most Stihl saws have inboard clutches. All you have to do to swap out a sprocket on a Stihl saw is remove the bar, remove a c-clip and washer, and sawp out the spur sprocket or rim. Takes about 2 minutes, tops. Outboard clutches take a lot longer to swap sprockets out on. Yes, outboard clutch saws are a PITA to deal with. You have to freeze the engine, and you typically need special tools to pull the clutches off with. You also have to remember that they are reverse threaded. This is true for inboard clutches as well. One beer too many and you can bend a piston rod thinking that you are loosening a clutch, when in fact you are tightening it (now, how could I possibly know that )

[stonebroke]

Where do you plan to get parts for this saw?

Stonebroke

[windthrown]

Now, there is a thought. All these cheap-o junker chainsaws are going to break down, and people are going to need parts for them. 

[stonebroke]

Maybe  they are the ultimate throwaway saw, First time you need anything other than bar and chain you just throw it away and buy a new one.

Stonebroke

[John Mc]

Or maybe if he's really lucky, they copied a Husky saw close enough that some of those parts will fit.

[Cut4fun]

How could you not know that this is not a MS361. Has to be more to the story. Wow. 

http://www.thegreenreaper.co.uk/showdetails.asp?id=2006

[361filer]

Here are the pics of my "Stihl" PN5200. Sorry if it offends anyone

Here is the gallery of the files.

I'm trying to get used to this system, and I have used the coppermine system only once before.

[Cut4fun]

Like I said, how could you not know that wasnt a REAL 361 when dude was handing it to you. 

That saw is listed as 49cc, 10cc less then a real 361 and Our Price: £149.99 new.

[joe_indi]

(Image hidden from quote, click to view.)

(Image hidden from quote, click to view.)

Here are the pics of my "Stihl" PN5200. Sorry if it offends anyone

Here is the gallery of the files.

I'm trying to get used to this system, and I have used the coppermine system only once before.

Oh Gosh!

This looks like the same Chinese saw that is flooding the market here.  It sells for INR 6000, which is roughly $US. 133.00.

361filer, this is one big ride that you've been taken on.
Beats the ones in Disneyland I think.

Order a minimum hundred pieces and they will even design a sticker with your Mother-in-law's name for you.

They are knockoffs of either the midrange Makitas or Tanakas.
The original parts from Makita or Tanaka should fit and out last the whole machine!
We see them here  as Bullet, Precision, Ideal .
Log on to alibaba.com and you will see some saws would really surprise you.

[JohnG28]

Im not sure that this will be too helpful, but you could tie a shot of rope to the rear handle, remove bar and chain, drain fluids, and have an ms361 look-a-like anchor for a boat

[JohnG28]

361filer, hope that I didnt offend you, I didnt mean to make light of your situation, I know that I dont appreciate being taken to the cleaners, was just trying to lighten up a crappy deal, and I know that if I was in your situation Id probably not be as calm as you seem to be, anyways, good luck to you, hope that you can get some use from this machine and its not a complete loss, and at the very least Im sure that you will not make such a misteak again