damaged piston/cylinder? husqvarna 254xp

[MartDalb]

Hi folks


New to the forums! but glad to be here!


Can someone, with more knowledge on chainsaws than me, have a look at this picture and tell me if the piston/cylinder is so damaged that it will cause the saw to stall/stop after only a few seconds after ignition?


Thanks for all help!

regards
Mj

 

[hotshot]

Yep, the piston is scored up, however I don't have a clue if your cylinder is OK from the one photo.

I'm suprised it starts right up, but don't run it anymore as further damage will likely occur.

Pull the top end and post a picture of the bore surrounding the exhaust port.

 

[s sidewall]

Straight gassed?, looks to be shot.

Steve, Samsung On5 using Tapatalk

 

[s sidewall]

Or mighty lean, air leak.

Steve, Samsung On5 using Tapatalk

 

[MartDalb]

Thanks!

I will try to take it apart tommorow, and post more images.
Don't wan't to put in alot of money on it before having You wise folks saying that it will, most likely, fix my issues!


Will post images asap

regards
Mj

 

[MartDalb]

update with more pictures (better)

Now, the question is the same, will this damage/wear be enough to make the chainsaw stall/die just after starting.
And, perhaps, is this worth repairing, If buying a piston/cylinder kit cheap of Ebay or the likes?

All help is greatly appriciated!

best regards
Mj

 

[Sepia]

The stalling is likely because of an air leak causing a lean condition as soon as the saw stars. And that lean condition is scoring your piston/cylinder. There is oil mixed in the gas correct? lol

Cylinder looks saveable, but looks like a new piston and ring are in order. Is the saw freshly rebuilt? It looks clean and dry inside.

 

[MartDalb]

Yes there is oil mixed in the gas.

The saw is not freshly rebuilt no.
I dried the cylinder/piston off before taking pictures.

The airleak, where should I start searching for such?

Is it even worth testing gas filter, ignition coil, carburator?

 

[Sepia]

Tons of info in this forum on testing for air leaks. I don't have any links off hand but you can do a search or someone will chime in. You will need a mityvac type tool that both pulls vacuum and applies pressure. Here is a vid by @Mattyo (Mathew Olsen) that explains the process.

 

[Sepia]

Never hurts to replace an old fuel line and filter. Coil shouldn't cause scoring, but may cause intermittent running. Could be carb related, but pressure/vac test is still required to eliminate the possibility of an air leak. If it has an impulse line be sure to check it for cracks/leaks.

 

[MartDalb]

ah special tools, damn aight.

By salvagable cylinder, does that mean I could reuse it as is, and "only" replace the piston+ring?

 

[MartDalb]

I searched for an impulse line, but not seeing any on this Husqvarna 254xp

 

[cus_deluxe]

I think that saw has an intake block with pulse passage molded in it, if its like all the other 2-series huskys. That cylinder will require sanding/acid to remove the transfered aluminum. It could get pricey to repair if youre unable to do it yourself. Looks like a fun project!

 

[MartDalb]

Now..please laugh and point fingers at me...I am new at taking apart chainsaws etc.

Since you said, air leak I just checked the gas line, and blew air into the fuel line, air came out of the little filter on the side, as I take it it should, so I popped my finger on it and checked if there were other ways the air got out. And I could hear air leaking from the gas cover. So i screwed it off and refitted it, that stopped the air leaking from there. Could that be "airleak"?

 

[MartDalb]

ok, so new cylinder check.
The airleak has to be found first though, without the tools for it, I guess it's a dead end for me, unless my little gas cover refit was causing the airleak.....?

 

[Sepia]

You are checking for an air leak into the crankcase of the engine. The fuel tank needs to leak air slightly.

 

[Sepia]

Read this thread to learn how to clean your cylinder:
http://www.arboristsite.com/community/threads/how-to-remove-aluminum-transfer-without-acid.248325/

 

[Sepia]

And read this to learn how to test for leaks:
http://www.arboristsite.com/communi...st-pressure-test-and-seal-replacement.291999/

 

[MartDalb]

okay, so it's gaskets, between piston and cylinder and the likes I need to check?

 

[Sepia]

Yes gaskets at base of cylinder and between carb and block, and between block and cylinder. Plus leaks at the crank seals.