090 cylinder plating.

[Sawrain]

Hi all,

So I picked up a well priced, but low on compression Stihl 090, checked the piston through the exhaust port, looked ok.

However there where a few issues when I pulled the jug off.

I’m probably going to get a hyway piston and see how the cylinder performs, but I thought I would get a second opinion, maybe from people who have seen more cylinders in this condition than myself.

Squish was .048 with gasket, 0.031 without.



Something happened at some point, few marks on the skirt as well, I won’t re-use the piston.


The worst transfer.


Other transfer, almost like someone ground it.


Below intake, feels ok.


Rest of plating, isn’t too bad.

 

[Deets066]

I Probly wouldn’t run it like that. If you really want to run it, send it to US Chrome to get plated.
If it’s just gunna sit on the shelf, then slap it back together.

 

[lehman live edge slab]

As you say looks like someone tried to feather in that bad spot, hopefully the price was right because that may have been a known issues with the saw.

 

[smokey7]

It looks like that saw ate something. I would look to see if any of the damaged spots could be ground out with a bit of raising and widening of ports to get rid of as much of the damage you can. Those little vertical scores won't mean too much in terms of compression

 

[Lightning Performance]

I see sanding marks everywhere. Betting the plating marks are from the that piston losing metal or you have plating issues like peeling at the port area. Show us the whole squish band.

 

[Hinerman]

I Probly wouldn’t run it like that. If you really want to run it, send it to US Chrome to get plated.
If it’s just gunna sit on the shelf, then slap it back together.

Can a new OEM P/C kit still be bought? If so, at what cost? Any idea?

EDIT: Piltz is selling them on E-bay for $450ish...

 

[lehman live edge slab]

I’ve seen them as low as 325$ not long ago, why would he have a cylinder for sale for a big saw that’s all you need is a ms362 with a new sprocket and 36” bar.

 

[BlackCoffin]

I’ve seen them as low as 325$ not long ago, why would he have a cylinder for sale for a big saw that’s all you need is a ms362 with a new sprocket and 36” bar.

it’s for the new piltz 090 hot saw. 13 pin rim, 160” bar and pico chain. Get sum!

 

[Lightning Performance]

it’s for the new piltz 090 hot saw. 13 pin rim, 160” bar and pico chain. Get sum!

I raffed

 

[Sawrain]

Thanks for the input .

I do think something more than wood chips might have been ingested.

Complete squish.



Piston intake side, exhaust was fine.

 

[drf256]

I think you can use both piston and cylinder personally.

You need to carefully blend the edges of the plating down to the aluminum so they don’t rub or chip (where there is damage). You’ll need to make sure that groove and any damage you blend isn’t proud to the bore.

The intake side of the piston can be smoothed with some sanding.

I’d be pulling that bottom end apart and looking at the crank large end, the pin bearing and the mains to see if the ingested debris was from them.

 

[Al Smith]

As is my mode of operation I've saved them worse than that .On that piston skirt business remember normally unless it's huge a low spot it will not hurt you but a high spot will .
That's a big old heavy Clydesdale of a saw .Speed plays very little into it plus you won't normally use it that much .I think you could smooth things out ,tune rich and use a rather heavy oil mix and be okay. It might smoke a tad bit,big deal .
As far as US Chrome I'm not even certain if they will do a blind end cylinder from what they say .

 

[Definitive Dave]

Us chrome will plate blind cylinders but millenium will not
Of the two millenium has nicer plating according to others in the indusrry

 

[Al Smith]

I suppose as large of a bore an 090 has it could be sleeved like I did the Mac 125 with a cast iron sleeve .It would be a black hearted beech to cut the ports in .You'd have to port map it and transfer the port shapes inside the liner and cut them that way .About 50 hours later you might have them or you might not . Your fingers would be so sore you couldn't hold onto a coffee cup for a week or two . I don't recommend it .

 

[Sawrain]

I think you can use both piston and cylinder personally.

You need to carefully blend the edges of the plating down to the aluminum so they don’t rub or chip (where there is damage). You’ll need to make sure that groove and any damage you blend isn’t proud to the bore.

The intake side of the piston can be smoothed with some sanding.

I’d be pulling that bottom end apart and looking at the crank large end, the pin bearing and the mains to see if the ingested debris was from them.

I think I will go with this, easy saw to split with the main bearings being needle rollers.

Hopefully I can get the lining to chamfer the way I want.

As is my mode of operation I've saved them worse than that .On that piston skirt business remember normally unless it's huge a low spot it will not hurt you but a high spot will .
That's a big old heavy Clydesdale of a saw .Speed plays very little into it plus you won't normally use it that much .I think you could smooth things out ,tune rich and use a rather heavy oil mix and be okay. It might smoke a tad bit,big deal .
As far as US Chrome I'm not even certain if they will do a blind end cylinder from what they say .

For sure, reality is it won't get run much, running good oil and safe tuning should help it live.

I suppose as large of a bore an 090 has it could be sleeved like I did the Mac 125 with a cast iron sleeve .It would be a black hearted beech to cut the ports in .You'd have to port map it and transfer the port shapes inside the liner and cut them that way .About 50 hours later you might have them or you might not . Your fingers would be so sore you couldn't hold onto a coffee cup for a week or two . I don't recommend it .

Good backup plan, maybe if it lets go completely.

 

[Deets066]

I suppose as large of a bore an 090 has it could be sleeved like I did the Mac 125 with a cast iron sleeve .It would be a black hearted beech to cut the ports in .You'd have to port map it and transfer the port shapes inside the liner and cut them that way .About 50 hours later you might have them or you might not . Your fingers would be so sore you couldn't hold onto a coffee cup for a week or two . I don't recommend it .

That is not somthing I’d be doing with company’s like US Chrome out there

 

[Al Smith]

It would only be done on a real ragged out cylinder IMO .Then again if you had enough money perhaps Wiseco could make an over bore .A lot of options but they all require mucho dinero .

 

[jacob j.]

That is not somthing I’d be doing with company’s like US Chrome out there

I was wanting to take an 090 jug out to 68mm but never found a suitable piston for it.

 

[Deets066]

I was wanting to take an 090 jug out to 68mm but never found a suitable piston for it.

I’m goin 70mm