Dead 290?? Any help out there - please!

[aztoad]

OK, I didn't know you already had a ring expander on hand.

Ammonia can free steel parts that are corrosion welded to aluminum parts by dissolving the corroded aluminum (and then it will dissolve the aluminum if you leave it soaking too long).

OK so now for the technical questions - I also saw that someone suggested muriatic acid (pool cleaning strength ~ 10% - 15% or so) but I'm hesitant to start anything too destructive given the cost of a new piston! Although we use this constantly to clean our salt cell...

When you say ammonia - are you referring to the general household cleaning strength or something stronger?

Is the soaking time in the seconds or minutes or hours range?

Thanks

 

[Lakeside53]

you can't use acid on your piston.... it will disolve the entire piston and leave the rings...


Here's OEM for $40...

http://cgi.ebay.com/STIHL-029-MS290...VQQcmdZViewItemQQ_trksidZp1638Q2em118Q2el1247

 

[aztoad]

you can't use acid on your piston.... it will disolve the entire piston and leave the rings...


Here's OEM for $40...

http://cgi.ebay.com/STIHL-029-MS290...VQQcmdZViewItemQQ_trksidZp1638Q2em118Q2el1247

Many thanks - I now am feeling a bit better as finances right now aren't lending themselves to being able to spend over $100 to get this running again!

Must have been really tired last night because I spent at least half hour in ebay looking for "stihl 290" and saw some parts saws but didn't run into this.

Now I at least feel confident taking the hot/cold approach and later today I'll try to chisel it out!

 

[aztoad]

WOW!! But now why??

The latest...

Just got one of the rings out - looks like much carbon hold the rings in.

Heating - allowing to cool - penetrating liquid - heating - allowing to cool ..

And a bit of ultrasonic cleaning allowed the lower to move enough to get it out. The lower looks great! I can't see a reason not to reuse it given how great it looks.

Which now raises the question - yes the saw was loaned out but my wife gave him the gas can too - so if not the gas - what would cause something like this to happen and how to avoid in the future?

Outside of not ever letting it out of my sight!

BTW - Thanks to everyone here - you guys are great and I wouldn't have gotten this far with this without all the help!

 

[Taxmantoo]

When you say ammonia - are you referring to the general household cleaning strength or something stronger?

Household strength will eventually remove an aluminum seatpost or handlebar stem from a steel bicycle frame, if the problem is white corroded aluminum expanding and tightening the joint.

Looks like you need some carburetor cleaner or carbon solvent if the rings are stuck in by burnt oil. Do keep track of which ring is which and which side is up.

 

[aztoad]

Household strength will eventually remove an aluminum seatpost or handlebar stem from a steel bicycle frame, if the problem is white corroded aluminum expanding and tightening the joint.

Looks like you need some carburetor cleaner or carbon solvent if the rings are stuck in by burnt oil. Do keep track of which ring is which and which side is up.

For now, I'm alternating the B-12 chemtool carb cleaner for an hour then liquid wrench penetrating lubricant after I saw what was holding the lower ring in!

The top ring is sloooooowly prensenting an edge so I'm hoping that by later this afternoon I might have it removed.

Already ordered new rings but this way I'll have a back up too.

Still wish I knew why this happened....

 

[Lakeside53]

Still wish I knew why this happened....

crappy mix...

 

[aztoad]

crappy mix...

I'd believe that in general but since I use the same gas mix for the FS 85 and SH 85 that we use almost every other day, I use up about 2.5 gallons every month or 2 - and always have used stihl oil.

The others all work perfectly without a hitch which is why I wonder if that is really the cause. Don't get me wrong - I have no clue and the gas could be as good a reason as the next but is the 290 more susceptible than the other units?

I had been using the 89 octane but recently started using the 91 when I heard that it was better.

If it was the mix - that is good news in one respect as that is something I can control!

 

[Darkness77]

Did the loanee use the supplied mix? Maybe he felt lowly enough borowing the saw and used his own. You never know.

 

[aztoad]

...and the plot thickens....

While I can't say for sure, I've known him for about 13 years and can't imagine him using anything but the can provided.

However, I asked him last night at the tournament if he had any problems with the saw or had he run out of gas and his comment was - heck no - we only cut up that one mesquite tree (at most 1/10 cord) but he did say that it bogged down a bunch and asked me when the chain was sharpened last.

I put a new chain on at Christmas of last year and only took down one tree in between but not being there - I just don't know.

Starting to wonder if these saws are having problems with the plastic containers I store the gas in (don't think they are Nalgene!) or if there was some additive placed in the local supply.

Just wish I could get to the bottom of it so it doesn't happen again.

Now for the sick part, it sure has been fun tearing it apart though...can't wait 'til the rings get here to get it buzzing again...

 

[kevin j]

Now for the sick part, it sure has been fun tearing it apart though...can't wait 'til the rings get here to get it buzzing again




same old song, tis only the beginning of the down hill slide.....craigs list, garage sales, then spending all the grocery money on saws 'because i didn't have one like that...'

sigh. so sad to watch another one afflicted.

 

[aztoad]

The saga continues...ideas? Suggestions? Meds?

...well since tournaments were over last night and I am finally back at home for a bit, I decided that rather than just half take this apart - I might as well go all the way and make it look real perty before I go and filth it up a bit.

Only problem is that I found another problem!! Hmmm this is kind of fun but I'm hoping that at some point I'll be able to put it back together and hear it make some noise!

It appears that now with everything nice and clean, I noticed a bit of extra movement in the oil seals on the oil pump side. When the blue oil seal was removed, the brown plastic cover to the bearings was observed to be wobbling and when I turned the crankshaft - it fell out!

Of course with my luck, I'm certain this is not just a plastic pop in - inexpensive part and am going to assume that the bearings need to be replaced and as long as I'm replacing one - that both should be replaced.

Am I thinking correctly and where can I find these bearings online? Dealership's parts / service person has been out due to medical problems and doesn't return calls yet so I'm in need of an online source. Tried Baileys - no luck for this.

Forgot to also ask about soft versus hard seals??

Any ideas or suggestions?

 

[West Texas]

Don't let it get you down; the first 029 ate my lunch for sure. But just consider that you are now enrolled in the 029 Graduate School and will be an expert on that hummer by the time you get it all back together and running again. The name of the Graduate School, is the 'school of hard knocks' -- a lot of us have been there and survived; I believe you will too.

 

[aztoad]

Don't let it get you down; the first 029 ate my lunch for sure. But just consider that you are now enrolled in the 029 Graduate School and will be an expert on that hummer by the time you get it all back together and running again. The name of the Graduate School, is the 'school of hard knocks' -- a lot of us have been there and survived; I believe you will too.

Appreciate the vote of confidence! I'm enjoying all but the delay in parts! Been taking motorcycles and cars and motors apart for about 40 years so while this is the first chain saw - motors in general don't worry me too much - but researching what actually happened so I can avoid it in the future is a lot of fun!

 

[Bowtie]

Appreciate the vote of confidence! I'm enjoying all but the delay in parts! Been taking motorcycles and cars and motors apart for about 40 years so while this is the first chain saw - motors in general don't worry me too much - but researching what actually happened so I can avoid it in the future is a lot of fun!

I will catch hell for this but I took my 029 super bearings to a bearing supply house and they got me new bearings of the same size and quality for 12$ apiece. They also supplied seals to fit the crankcase. That saw has been running ever since with zero problems.

EDIT Make sure if you do this they code the bearing and supply a bearing rated for the speed and load that the factory bearing is coded at. I would think any reputable supplier would do this, but ya never know.

 

[aztoad]

I will catch hell for this but I took my 029 super bearings to a bearing supply house and they got me new bearings of the same size and quality for 12$ apiece. They also supplied seals to fit the crankcase. That saw has been running ever since with zero problems.

EDIT Make sure if you do this they code the bearing and supply a bearing rated for the speed and load that the factory bearing is coded at. I would think any reputable supplier would do this, but ya never know.

Thanks - I seem to recall a bearing shop over in Mesa!! Much appreciated!

...and thanks for the heads up - that too would be my luck!

 

[Taxmantoo]

crappy mix...

...or maybe the user didn't shake the can before pouring?

 

[Lakeside53]

...or maybe the user didn't shake the can before pouring?

That would have to be really crappy mix.. decent mix requries no shaking..