What in the worls

[kjmatson]

Working on a stihl 036, have done absolutely nothing to the exhaust and the top of the piston shows at bottom dead center. Anyone seen this before???

 

[OddSawz]

Have not seen that before. How does the port look at TDC? Are you using a base gasket?

 

[kjmatson]

Have not seen that before. How does the port look at TDC? Are you using a base gasket?

No base gasket, tried it with and without. Looks good at TDC

 

[OddSawz]

What’s the story? Are you using the original jug with a new piston? Original or Aftermarket parts?

 

[kjmatson]

What’s the story? Are you using the original jug with a new piston? Original or Aftermarket parts?

Original just and piston. Replaced crank bearings than popped it back on

 

[benmyers]

Are you certain the port hasn't had any grinding done on it?

 

[kjmatson]

My understanding is that it hasn't. I just asked the owner and he said nothing has been done to it. It was handed down to him from his father. Im wondering if it had been tinkered with

 

[benmyers]

I came across a 372 one time that had a similar issue. Wouldn't run right and eventually pulled it apart and found that someone had done some port work but didn't really target any numbers- just hogged out material then polished it up.

 

[kjmatson]

The difference is .060, that's crazy

 

[kjmatson]

thinking I will have to epoxy or jb weld the .060 if that will even hold

 

[benmyers]

I wouldn't count on that holding for long....

 

[RED-85-Z51]

Ive seen piston at bdc but never ring

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[kjmatson]

Ring isn't showing just .060 of the piston

 

[kjmatson]

problem is it is also cutting off .060 of the upper transfers and im not grinding them

 

[kjmatson]

Squish as is right now with no base gasket is .020. Just going to have to deal with it i suppose. Never seen it before

 

[kjmatson]

ATDC 82 - ABDC 172

 

[RED-85-Z51]

Ring isn't showing just .060 of the piston

I thought that was the ring peaking through the bottom there at the edge of the port.

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[Mad Professor]

View attachment 854354
Working on a stihl 036, have done absolutely nothing to the exhaust and the top of the piston shows at bottom dead center. Anyone seen this before???

Are you sure no Chinesium parts are involved?

What does intake/ex look like at TDC?

If you have a oem piston look at pin height vs crown/skirt vs this one

 

[Woodslasher]

Well heck, just look at the muffler gasket marks. There’s still “meat” inside the gasket outline so I doubt someone ground on it.

 

[kjmatson]

Ok numbers aren't bad. Messed up earlier. Exhaust 108 - 83. Intake 105 - 84.