Scored Piston - Jonsered 2258

[CristiRo]

Than you guys for helping me out!
I had, a couple of times WOT the saw for 2 sec. no .more. I heard how it hit the limiter. So, it could be a lean condition!
The air filter is nylon, the yellow one!
I'm gonna go to the dealer and hook up to the diagnostics and see the fuel settings! Maybe they are off...bad.

 

[CristiRo]

Here are some photos:

 

[blsnelling]

I can't tell for sure, but is there any aluminum transferred to the cylinder?

 

[blsnelling]

Did you remove the muffler before modding it? Did you make sure all debris was cleaned out?

 

[CristiRo]

I can't tell for sure, but is there any aluminum transferred to the cylinder?

I can't really tell...don't know how it shoul look like. Just put my finger into the cylinder and where is that scoring from the piston I felt it with my nail, but not sa rough...

Did you remove the muffler before modding it? Did you make sure all debris was cleaned out?

Sure, I took off the muffler, made the modification and than cleaned with compressed air very very well.
I than shake the muffler to make sure no debries remained in the muffler.
Should I buy a new ring? It has some minor marks in that exhaust side...

 

[blsnelling]

I would sand the piston just enough to smooth the high spots and install a new ring. Make triple sure that there is no transfer in the cylinder.

 

[blsnelling]

I also recommend that you remove the transfer covers and make sure you don't have a defective seal. I would then pressure test after assembly.

 

[CristiRo]

Will this gasket silicone be good to seal the transfer covers?

http://www.reinz-industrial.com/EN/PRODUCTS/Sealing-Compounds/REINZOSIL.aspx

From the data sheet: "This highly elastic universal sealing compound is resistant to mineral oils and numerous synthetic oils, lubricants, petrol, diesel oil, greases, hot and cold water, detergents, sunlight, ozone, and sea water.
REINZOSIL is suitable for continuous operation in the temperature range between -50 °C and +250 °C (briefly up to 300 °C)"

 

[blsnelling]

Silicone is not the proper sealant for gasoline. If they're intact you won't need sealant. They're essential a rubber o-ring.

 

[CristiRo]

@blsnelling , what fuel/oil ratio are you using in your chainsaws?

 

[blsnelling]

I run 32:1 synthetic in everything I own. That includes brand new stock saws, ported saws, and even 70 year old 2-man saws.

 

[CristiRo]

@blsnelling You were correct, there were some aluminium transfers. With a scotch-brite i removed them as much as i could, not an expert...



Now I've got one problem. Don't know how to reamove the piston. The safety clips ar completely round...

 

[user 149785]

The clips will have a void between the ends.use a pick tool slide the clips around till about a 1/16" is exposed in the piston cut out on the lower left side of the wrist pin and use the pick tool to pry out the circlip.cylinder looks good.should run just fine.

 

[Little Al]

It's the first run after more muffler mod, probably I should have put more oil into the mix.
I'll try to see how it runs with more oil into the mix, not pushing the saw too much, and then buy a new piston and ring.
I don't have pics with the cylinder but, can be used?

Agree with Brad looks to be lean tuned.More oil is not required a mix of 32/40to 1 is fine its the carb adjustment ( possibly running lean or an air leak If the saw belonged to me I would strip & check & rectify the faults found It will not get better & running in that condition could cause further damage & require you to dig deeper in your pocket for more cash.

 

[Little Al]

All i can find is: LS+ Husqvarna, Sthil HP, Sthil HP ULTRA, and i found an online shop that has MOTUL 800T 2 stroke.

Do you have dirt bike shops locally? any Jaso FC or FD rated oil or ISo eqiv will be fine Motul 800is a bit over kill as it has an additive to keep power valve free operating not needed on a saw Motul 710 is the same less the additive

 

[CristiRo]

@Little Al HP Ultra is no good?
Before the scoring has appeared i used 40:1 and the i wanted to try it at 47:1...
I'll go deep to find the problem! :d

 

[Little Al]

@Little Al HP Ultra is no good?
Before the scoring has appeared i used 40:1 and the i wanted to try it at 47:1...
I'll go deep to find the problem! :d

Stihl oil is OK ( I can't get on with the smell) But in Europe I believe it is blended by Castrol There are a number of oils blended by the oil company's & labeled under theIr brand that is equal if not better in quality & lower in price than the chainsaw brand named product I always use 32/1 ratio in all my saws & the saws I service for a commercial logging company. A lot of Folk Tales are spread re oil most of it false have been brought about by the so called emissions limiting & the saw manufactures are on to a winner if your saw utters the dreaded "Death Rattle" possibly due to minute oil amounts in the mix in the shortest possible time after warranty has expired. It's an emotive subject.

 

[pgdalton]

Is that a gouge I see near the bottom of the cylinder in the seventh pic?

 

[CristiRo]

Is that a gouge I see near the bottom of the cylinder in the seventh pic?

Please quote the picture to understand wich is it

 

[mountainlake]

@Little Al HP Ultra is no good?
Before the scoring has appeared i used 40:1 and the i wanted to try it at 47:1...
I'll go deep to find the problem! :d

The oil isn't the problem, lean tuning is or maybe lugging it too much if its a auto tune. Steve