STIHL Stihl 090 decompression release problem

[Gord]

Picked up a Stihl 090 recently and physically in beautiful shape but had no compression, turned out to be the compression release will not seal - had the jug off and she is in great shape inside, tried cleaning up the valve and seat but still leaks, was thinking about removing the whole assembly and replacing it or re-lapping it but can't even budge it, any ideas?

 

[Lightning Performance]

Picked up a Stihl 090 recently and physically in beautiful shape but had no compression, turned out to be the compression release will not seal - had the jug off and she is in great shape inside, tried cleaning up the valve and seat but still leaks, was thinking about removing the whole assembly and replacing it or re-lapping it but can't even budge it, any ideas?

Send that junk here for disposal

 

[Gord]

Rightttt - one of the nicest ones that has come though here so I BOUGHT IT- ALSO HAVE THAT SAME ADDICTION

 

[Deets066]

Had to replace the decomp on my 090 as well.

 

[Gord]

Had to replace the decomp on my 090 as well.

How did you get the old one out.... this is really in there- don't want too wreak anything

 

[Deets066]

Mine came right apart.

 

[Gord]

Mine came right apart.

The whole unit with the screwdriver slot in it?, mine is really in there, if I could just lap the little valve back in I would but think it's beyond that.

 

[Deets066]

The whole unit with the screwdriver slot in it?, mine is really in there, if I could just lap the little valve back in I would but think it's beyond that.

I’ll take another look at mine tomorrow and refresh my memory. I believe it’s a 3 piece

 

[Gord]

This is what the unit looks like to fit mine but will try to lap it back in first but is a real sloppy fit between the inner valve and the shaft

 

[Gord]

Finally got the whole unit out and the copper washer at the bottom was not doing it's thing- had to come out anyway so think I will order a new unit and put it in for what it's worth- fixed the old one and it works but feel better about replacing it.

 

[Lightning Performance]

Finally got the whole unit out and the copper washer at the bottom was not doing it's thing- had to come out anyway so think I will order a new unit and put it in for what it's worth- fixed the old one and it works but feel better about replacing it.

090 top end is worth a decomp. Good call.