Husky 346xp piston cylinder issues

[Frazer Burley]

Hey folks

 

Got a 346 that has had an aftermarket cylinder/piston in after a dry fuel mix incident a few years ago. Has run for a couple years ok, never really as powerful but i did get the cheapo ebay one so to be expected. Recently stopped running needing throttle on to start then dying. Very low compression. Ripped it down and found this...

 

First picture shows intake side. Little scoring. Would that cause issues?

 

Second picture exhaust side. One strong line of scoring where piston ring was fused to cylinder... Tan discolouration around top area

 

Third picture is wrist pin showing indentation from needle bearing on one side only. Whats that about?! assume it's not good...

 

Fourth picture is showing scoring at top of cylinder on exhaust side.

 

Maybe slightest up and down play in con rod. maybe not, hard to tell...

 

Any help be good cheers

IMG_1736.DNG IMG_1737.DNG IMG_1738.DNG IMG_1741.DNG

Edited March 20, 2022 by Frazer Burley

[Frazer Burley]

[adw]

Picture one, has the ring peg come out? I have also seen wrist pins come very loose in the piston causing all sorts of issues, the joys of after market cylinders.

[Frazer Burley]

Thanks for reply Adw, yep look like the locator pin has disappeared... So you think it's all down to shit aftermarket kit? Whats a good one that's not as pricey as OEM? or is it really OEM or go home?

 

[Khriss]

Not cleaning filters could also do that, looks pretty rough after a couple years running  🙁 k

[spudulike]

Looks like the gudgeon pin has worn on one side....measure both ends and compare to the middle. One end will probably be smaller than the others.......strangely, the pin often wears and the piston doesn't.

 Seen this on old OEM pistons...one a 064 Stihl and also on  Nepias 262XP .

The actual piston doesn't look too bad.

The marking around the exhaust port looks pretty iffy and shows signs of seize.

If that ring location pin has fallen out, it won't be holding the ring in place - if the ring is pushed in to the grove, does the pin hold it? if not, it has gone.

You usually take out the piston in a big way when they fall out....or they end up embedded in the combustion chamber squish band!

[Stubby]

54 minutes ago, Frazer Burley said:

Hey folks

 

Got a 346 that has had an aftermarket cylinder/piston in after a dry fuel mix incident a few years ago. Has run for a couple years ok, never really as powerful but i did get the cheapo ebay one so to be expected. Recently stopped running needing throttle on to start then dying. Very low compression. Ripped it down and found this...

 

First picture shows intake side. Little scoring. Would that cause issues?

 

Second picture exhaust side. One strong line of scoring where piston ring was fused to cylinder... Tan discolouration around top area

 

Third picture is wrist pin showing indentation from needle bearing on one side only. Whats that about?! assume it's not good...

 

Fourth picture is showing scoring at top of cylinder on exhaust side.

 

Maybe slightest up and down play in con rod. maybe not, hard to tell...

 

Any help be good cheers

IMG_1736.DNG 23.82 MB · 5 downloads IMG_1737.DNG 26.87 MB · 6 downloads IMG_1738.DNG 23.38 MB · 3 downloads IMG_1741.DNG 20.09 MB · 4 downloads

Are you sure it was neat petrol and not an air leak . I ask coz putting on another pot and piston if it is an air leak will just let it nip up again .

[spudulike]

They often get air leak issues on the inlet manifold through splitting or badly re-fitting and also on the clutch side crank seal!

[adw]

Not that bloody crank seal again!

[Frazer Burley]

34 minutes ago, Khriss said:

Not cleaning filters could also do that, looks pretty rough after a couple years running  🙁 k

Could be guilty 🙄