Some grotty photos for you to look at (scored piston content)

[Darkslider]

Bought this 200t listed as cutting out at idle occasionally hoping it'd be a carb issue, started and ran but thought I'd check the piston anyway. Wish I hadn't now. 😂

 

I'm unable to get a compression reading as the angle the plug enters the cylinder means my adaptor contacts the piston on the corner at tdc. 

 

With no plug in it pulls over but there's a bit of a snag a few degrees either side of TDC. It feels like it wants to 'spring' into tdc then spring out again if that makes sense. This is with recoil starter and chain brake both removed. When trying to pull it over it feels like trying to start a diesel so I'm guessing it's got good compression on top of this tight spot.

 

 

Would you put a pot and piston in this? Try a different comp tester and go from there? Or send it back? (Possibly an option)

 

4th photo is of the cylinder which doesn't look too bad to my eye but prepared to be corrected on this. 

 

I don't remember it being so hard to pull over when I first took it out the box a few days ago so I've left it soaking overnight in case I've disturbed some carbon but would appreciate any thoughts in the meantime!

 

Cheers all!

 

Edited February 21, 2021 by Darkslider

[Darkslider]

[Wolfie]

Looks toast to me, but soon there’ll be some better saw mechanics than me that will comment.

[ChrisNewport]

Yup, thats no good. piston is scrap and cylinder will be worse on exhaust side than it is on inlet side, it may clean up with a bit of work but it may not.

 

I assume you bought it off ebay. If you send it back they may be a honest seller with no knowledge of the lean seizure and refund you. If they advertised it as spares or repairs hoping this was their get out of jail card because they knew of the lean seizure and you tell them that the piston is scored they will know youve had it apart and will inform ebay of this and then they dont have to give you your money back if it goes to ebay to settle the dispute.

[Stubby]

9 hours ago, Darkslider said:

If you go down the new pot and piston rout be sure to find out why it nipped up in the first place . Could be an air leak from somewhere . Don't want it to happen again strait away .

Edited February 21, 2021 by Stubby

[Paddy1000111]

It's dead Jim! If you replace it I highly recommend going OEM, especially if you want it for future use! 

[spudulike]

As others have said, it is toast....burnt toast!

The availability of quality AM pistons is very difficult at the moment and am personally just using OEM top ends on all seized MS200s that's come in now.

If the owner has sold it as used and working, you have a comeback, if he has described it as bogging, he may argue that he didn't know it had seized. Most don't if the rings are still free as the saw still works! 

You have to look at the rest of the saw to take a view on spending on it. Looks well used and dirty but most are now!

[Khriss]

10 hours ago, Darkslider said:

Thats fvvkeed  oh dear . Hmmm   ( send the bugger back       )

[Paddy1000111]

On the front of sending it back, how much did you pay? I paid £113 for a non runner pos that was destroyed 😂. The pulling into place at tdc, you sure that's not the magnet on the flywheel pulling on the coil? 

[bmp01]

10 hours ago, Darkslider said:

With no plug in it pulls over freely but there's a bit of a snag a few degrees either side of TDC. It feels like it wants to 'spring' into tdc then spring out again if that makes sense. This is with recoil starter and chain brake both removed.

Proper knackered.

That springing into position around tdc is likely to be the flywheel magnetism and the coil interaction - more noticable when piston and ring friction is low.