Where does this crud come from?

[mheim1]

Pulled the cylinder of this 034 due to low compression (cylinder not bad, will clean up, piston will be replaced).
What I discovered underneath is pretty much a greasy mess:

Is that what you get from running to rich of a mixture (note: it's all the way down in the case as well)?
Just wondering.
Thanks.

 

[madhatte]

Looks like sawdust snuck in with the mixture. Poor/absent air filter is my guess.

 

[stihlman32]

What the piston look like? Got any pics? Could confirm madhatte's diagnosis...

 

[thomas72]

Also looks like blow by from a worn top end like you said. 034 is a good saw.

 

[mheim1]

piston

The piston (exhaust side) looks like this:

 

[stihlman32]

The piston (exhaust side) looks like this:

What about the intake side? I would think if it's sucking crap through the filter or the filter is removed you would find significantly more scarring on that side.

 

[mheim1]

What about the intake side? I would think if it's sucking crap through the filter or the filter is removed you would find significantly more scarring on that side.

Intake side looks fine.
I am starting to think it came through the base, as the gasket was almost entirely disintegrated (was tough to tell by what's left of it).

 

[Fish]

Definitely from not using Amsoil or Klotz.......

 

[Fish]

Definitely dirt ingestion, seal or gasket, impulse line maybe, but that would put crud in the carb too.

 

[stihlman32]

Intake side looks fine.
I am starting to think it came through the base, as the gasket was almost entirely disintegrated (was tough to tell by what's left of it).

I think you're on the right track and Fish seems to confirm it.

 

[mheim1]

Thanks guys.
I'll make sure to check all the connections and rubber before putting it back together. The bearings seam fine and the inside case might just need a good wash.

 

[porsche965]

Shows just how tough these 2 cycle engines really are.

Reminds me of women and automobiles....just run them until something goes wrong. Then its "I didn't have any idea...."

 

[blsnelling]

Definately dirt ingestion from somewhere, probably the air filter, or lack there of.

 

[whitedogone]

Thanks guys.
I'll make sure to check all the connections and rubber before putting it back together. The bearings seam fine and the inside case might just need a good wash.

Be careful with that.

 

[mheim1]

Be careful with that.

I'm thinking (and please correct me if I'm wrong) wiping of what I can get, air pressure, mix, air pressure, mix,...; it'll be messy but at least I don't have to split the case and put new seals on.
:censored: Now I'm thinking about new seals anyways.

 

[whitedogone]

I'm just not sure it's a good idea to "rinse" out the lower. IMO, you're just asking for trouble unless you go all out and split the case and flush out the races and install new seals. Short of that, I might just wipe out what I could get to and call it good.

 

[rmh3481]

We fill the case with mixed gas and let them soak. Then pull the seals and spray out the bearings.

 

[whitedogone]

Sounds like a decent plan. Bottom line is not to get all that crud in the bearings and behind the seals

 

[Cantdog]

Sounds like a decent plan. Bottom line is not to get all that crud in the bearings and behind the seals

It's already there. I'll bet when you pull the seals you'll find the outside of the race, between it and the inside of the seal packed with the same crud.
I'd pull the seals and flush, flush, flush with mix. I use a small acid brush to clean everywhere I can reach. No sense doing the rest of the topend work without building on a good clean bottom. This is the worst I've seen. Looks like it was run on 10-30 Quakerstate!!! I would probably fill the entire case with mix and let it sit overnight at least, before I pulled the seals. Might soften it up a bit and quicken the whole process. Good luck.

 

[olyman]

Looks like sawdust snuck in with the mixture. Poor/absent air filter is my guess.

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