Stihl 029 piston pictures. Opinions?

[sika]

Feel like I am spamming the board a bit.

I have seen and read many post's on partial rebuilds. I am pretty confident I can manage it.

The saw is a 15yr old + Sthil 029 Farmboss. My dads. You can see form my other posts I have been sorting this out lately after very little maintenance while he had it.

I am going to do a compression test on this, I wish I had those figures before I posted this but I don't yet.

Today I took some pictures of the piston from the exhaust side of the bore.

Just after some thoughts on how it look in there. I realize it is pretty dirty on the outside.

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[atlarge54]

????? Maybe time to switch to synthetic oil?????

 

[workshop]

I've seen worse that still ran good.:msp_wink:

 

[ROWDY]

????? Maybe time to switch to synthetic oil?????

That's prime reason I buy the pricey oils. For the reason in those pictures. The best burn up, and burn out!

 

[sika]

????? Maybe time to switch to synthetic oil?????

Okay. Will try that.

Thanks.

 

[SkippyKtm]

Feel like I am spamming the board a bit.

I have seen and read many post's on partial rebuilds. I am pretty confident I can manage it.

The saw is a 15yr old + Sthil 029 Farmboss. My dads. You can see form my other posts I have been sorting this out lately after very little maintenance while he had it.

I am going to do a compression test on this, I wish I had those figures before I posted this but I don't yet.

Today I took some pictures of the piston from the exhaust side of the bore.

Just after some thoughts on how it look in there. I realize it is pretty dirty on the outside.

View attachment 290931

View attachment 290932

Yes, I agree with the other posters in that a good synthetic oil would have prevented the carbon buildup.
Looks like some carbon scoring occured in there, but if you decarbonize the cylinder it'll probably be OK. What's the compression reading? If the reading is good, there's a good chance you won't need to rebuild it.

 

[brokenbudget]

looks like the guy likes to run it on old gas. let alone crappy oil.

 

[ROWDY]

Sea Foam could be a thought.

 

[jughead500]

I've burned Dinosaurs for years and never have had build up.:confused2:

 

[sika]

What's the compression reading? If the reading is good, there's a good chance you won't need to rebuild it.

Tested compression using a push in Workmate tester with schrader valve and which has a rubber end not a 14mm threaded end. Maybe not the best, mate pushed it hard in while I turned it over.

100PSI.

So its getting a little tired yeah? Normal would be 110-150 I am thinking.

Might try it again when my thread in tester arrives.

 

[Fish]

Yeah, slap it back together, put some Amsoil in it....

Within a week it will be a new MS290 with a brand new air filter...... Nuff said!!!!!!!!!!!!!!!!!!!!!!!!

 

[Fish]

Put Klotz in it, it will turn into an MS310!!!!!

 

[atlarge54]

Slap in a quadruple electrode iridium plug and he'll be needin' a 36" bar.

 

[sika]

Yeah, slap it back together, put some Amsoil in it....

We get Amsoil in NZ.

It is about $27US for a quart bottle of Amsoil Sabre Pro.(950mls).

Just picked up some Castrol Power RS TTS 2T fully syn. for the same price. It is JASO FD rated. Will try the Amsoil next time around.

 

[ROWDY]

We get Amsoil in NZ.

It is about $27US for a quart bottle of Amsoil Sabre Pro.(950mls).

Just picked up some Castrol Power RS TTS 2T fully syn. for the same price. It is JASO FD rated. Will try the Amsoil next time around.

I would really like to see what an additive product does to clean that up. Before and after pictures would be cool. I chose to suggest "Sea Foam" because, its mostly sought for, to clean up engines like that. I never knew if it really works as good and as advertised. Please keep up posted on your progress with any product you use.

I also believe that your saw would be in good shape for compression with a simple change of piston rings. Blocking your exhaust that bad, trapped more heat in the engine for more excessive ware.

 

[sika]

I would really like to see what an additive product does to clean that up. Before and after pictures would be cool. I chose to suggest "Sea Foam" because, its mostly sought for, to clean up engines like that. I never knew if it really works as good and as advertised. Please keep up posted on your progress with any product you use.

I also believe that your saw would be in good shape for compression with a simple change of piston rings. Blocking your exhaust that bad, trapped more heat in the engine for more excessive ware.

Hey thanks.

I was thinking piston rings too. I think this may be a 45mm model not a 46mm bore. Will have to check all that before ordering rings.

Will have to google Seafoam to read about that.

 

[Stihlofadeal64]

If you're going to the trouble to re-ring the saw, then you need to know that you will of necessity need two new oil seals (the ones made for when the clam shell engine is broken completely down). In the process of clean up and decarbon you might as well plan to replace the fuel line, fuel filter, and impulse line. It makes no sense to tear it completely down without doing these items if it has significant age and has had little service. A good set of Caber rings may provide you with a revival of compression. As has been suggested the synthetic oil is a very good recommendation as well.
There are quite a few threads here on the site that have pictorial/instructions of the tear down process. (might as well get a kit for the carb if you're at it -- that way the fuel system will be in upstanding condition when you're done). Check your air filter as well, if it has seen its better days go ahead and replace it as well. Just my 2 pennies. Happy Sawing.

 

[CTYank]

Part of the problem with the engine is the operator. It's been babied far too much; 2-strokes don't like that.

Get the main mixture where it should be, and RUN it. WOT for a series of max diam bucking cuts, with less than 20 seconds between. You'll clear the deposits right quickly. :cool2:

Oh, make sure the spark-arrestor screen is in place first, or keep a garden hose handy.

Don't cheap-out with the oil.

 

[Fish]

I would really like to see what an additive product does to clean that up. Before and after pictures would be cool. I chose to suggest "Sea Foam" because, its mostly sought for, to clean up engines like that. I never knew if it really works as good and as advertised. Please keep up posted on your progress with any product you use.

I also believe that your saw would be in good shape for compression with a simple change of piston rings. Blocking your exhaust that bad, trapped more heat in the engine for more excessive ware.

I was kidding...............

 

[sika]

What size piston? 45mm or 46mm

Having trouble figuring out what size rings to order.

I don't want to take it apart right now and measure cause I am still using it. Would rather order then get the job done in a day.

All info I can find is "older models" use 45mm rings/piston.

Mine is 15years old.