Husqvarna 390xp backwards piston

[ELECT6845]

2015 model saw that appears to be very low hour. Not much dust or debris on this saw at all. Covers are mainly dirty from sitting at the repair shop. Think someone at the factory was having a bad day?

 

[Fruecrue]

There’s more debris and carbon than I would have guessed. Must be some good bevels on the exhaust port.
Any cylinder pics?

 

[ELECT6845]

Cylinder has some bad scratches above the ex. port and a few big gouges on the port itself

 

[XP_Slinger]

Wow, that’s a shame. Any other damage?

 

[ELECT6845]

Wow, that’s a shame. Any other damage?

No everything else looks good. Working on porting the new cylinder today.

 

[RIDE-RED 350r]

That piston looks like it fell victim to a lean condition burn down. Did it have an air leak? Amazingly enough it doesn't look like either of the rings are broken...

 

[RIDE-RED 350r]

Wait a sec, looked again...bottom ring broken??

Piston still looks melted though

 

[AVB]

Looks more like straight gassing. Where's the original plug as the plug in the picture looks brand new? It is highly likely that it was greyed from aluminum transfer.

 

[Cut4fun]

Have had 2 54cc come in back to back almost with pistons backwards. Were still running. I always wondered if factory screw ups or not.

 

[ELECT6845]

Once I get the new cylinder done I will vac/pressure test it. The plug in it was brand new so I'm not sure if it was straight gassed or not. Regardless it wasn't going to run forever with the ring end gaps passing the exhaust port.

 

[angelo c]

Once I get the new cylinder done I will vac/pressure test it. The plug in it was brand new so I'm not sure if it was straight gassed or not. Regardless it wasn't going to run forever with the ring end gaps passing the exhaust port.

Joe, any ideas on how long it ran like that ?

 

[RIDE-RED 350r]

Once I get the new cylinder done I will vac/pressure test it. The plug in it was brand new so I'm not sure if it was straight gassed or not. Regardless it wasn't going to run forever with the ring end gaps passing the exhaust port.

You betcha! Pretty amazing that it ran more than a few minutes before hanging a ring the in the exhaust. I'd be willing to bet in this case that the bottom ring snagged due to the meltdown. Crazy that it came from the factory with the piston in backwards.

 

[ELECT6845]

All better now.

 

[RIDE-RED 350r]

Woa woa woa!! What is this "Magnum" monkey business???!! Lol!!


Looks great man! 190psi, BG deleted?

 

[ELECT6845]

Woa woa woa!! What is this "Magnum" monkey business???!! Lol!!


Looks great man! 190psi, BG deleted?

Base and chamber have been cut. Cylinder ported.
Magnum sticker is to piss off the Stihl guys.

 

[RIDE-RED 350r]

Base and chamber have been cut. Cylinder ported.
Magnum sticker is to piss off the Stihl guys.

EXCELLENT! dot dot dot on all points

 

[earlthegoat2]

Base and chamber have been cut. Cylinder ported.
Magnum sticker is to piss off the Stihl guys.

Should have got rid of that Xtra Plastic decal while you were at it.