deja vu... help with a Stihl 029/039

[IowaDiver]

I am by no means a small engine expert... which is why I lean on you guys. A year or so ago I stumbled upon a great looking 029 that wouldn't run, and long story short, you guys walked me through diagnosis and a full rebuild including upgrade to a 039 piston and cylinder and to top it off, a muffler mod. So the saw was running great, love it!

then Hurrican Matthew blows through, a large oak blows over out front of my house and lies accross the road, blocking access to the 20 or so homes at the dead end portion of the road, so the family and I run out (in the hurricane!) and I start cutting up the tree and we clear the road. Not 40 minutes later an even larger tree gets blown over right where we were working! We head out in the storm to clear the road once again... Ok, the "save the day" story is over.

The next day, storm has blown through, we go out to start clean up... 7 downed trees and plenty of debris to get rid of. Saw won't start. Here is what I come up with...

-saw seems flooded.... so I pull the plug and air filter and blow compressed air into the carb and cylinder to dry it out. reassemble, one pull on the full choke setting and the start starts up and dies within/3-5 seconds... basically chugs10-15 times and quits.
-Keep pulling on lower choke setting and continue pulling on zero choke setting... nothing, won't start.
-I repeat this process a few times with the same result.
-last attempt I try pulling the saw on zero choke and it starts after 2 pulls, runs a second or two longer, but dies... same result.

compressions is 100-120. did I scorch this piston/rings? I havn't messed with tearing into a saw since last winter so I need a little help with trouble shooting steps.

Side note... I was cutting in heavy down pour rain... not to mention the road was flooded and was consistently running water through my chain as the bar touched into the standing flood water. Would all of this water exposure have caused an issue?

help...

 

[Stihlsmoking]

I'd say if your at 120-130 that's low pull muffler and look at piston for scoring ? But does sound like might need rings ? Or do vac/pressure test ? Also I've read on here not to use compressed air on carbs ?

 

[heyduke]

I'd say if your at 120-130 that's low pull muffler and look at piston for scoring ? But does sound like might need rings ? Or do vac/pressure test ? Also I've read on here not to use compressed air on carbs ?

check your fuel line. if there is an impulse hose (i can't remember) check it. check the fuel filter. check the carb mounting screws and/or clamps (again i can't remember) for tightness. that is look for air leaks between the carb and cylinder. did you store the saw with fuel in it? if so, buy a new carb.

100-120 is very low for a saw with almost no hours on the top end. as suggested above, inspect the pisto/cylinder thru the exhaust port and perhaps the spark plug hole.

 

[IowaDiver]

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[IowaDiver]

upon inspection of the cylinder via the exhaust port it looked pretty clean... espeically compared to what I remember finding when I first got the saw and the piston was toast. I inspected the fuel filter, lines and carb and all looked good. I reassembled and gave a pull or two with zero choke and it sputtered to life... pretty weak, then died about 10 seconds later. tried again... same thing... Is this odd for it to start since I didn't choke at all? of course it died, so I check compression again... 110 was the consistent reading I got. What should it be?

My untrained gut is telling me to put some rings in the saw.... would this be your first choice or swapping for a new carb? I'm mostly leaning towards this due to the compression test.

 

[ZeroJunk]

Looking at the photo it is more likely you have a problem with your tester.

You can buy a new carb for that saw on eBay for $15 that will work fine.

And, as has been mentioned check you fuel line and impulse line for leaks.

 

[heyduke]

upon inspection of the cylinder via the exhaust port it looked pretty clean... espeically compared to what I remember finding when I first got the saw and the piston was toast. I inspected the fuel filter, lines and carb and all looked good. I reassembled and gave a pull or two with zero choke and it sputtered to life... pretty weak, then died about 10 seconds later. tried again... same thing... Is this odd for it to start since I didn't choke at all? of course it died, so I check compression again... 110 was the consistent reading I got. What should it be?

My untrained gut is telling me to put some rings in the saw.... would this be your first choice or swapping for a new carb? I'm mostly leaning towards this due to the compression test.

i don't trust compression testers unless they have been proven to be accurate. lift the saw by the starter rope. if it doesn't cause the saw to turn over, you probably have enough compression to run. also, if your compression is bad, you should feel significantly less resistance when you try to start the saw. the symptoms you describe sound like a fuel delivery problem and/or an air leak at the carb. as stated above carbs are cheap. you might be surprised by the low cost at your local stihl dealer. i wouldn't recommend rebuilding the carb since many modern carbs have plastic check valves that can't handle ethanol. you didn't mention if the saw had been stored with fuel. don't worry everyone does it at some time. a lot of guys do it more than once. new rings on that saw are a pain in the ass. you have an hour's work before you can even pull the cylinder. check the obvious stuff first. good luck with storm clean up.

 

[IowaDiver]

Sorry I didn't answer the fuel question... Yes it was stored with fuel in it. So I'm going to go ahead and swap for a new carb and fuel lines to see what impact it has. Thanks all for your support!

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[heyduke]

Sorry I didn't answer the fuel question... Yes it was stored with fuel in it. So I'm going to go ahead and swap for a new carb and fuel lines to see what impact it has. Thanks all for your support!

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good luck, let us know how it goes.

 

[HarleyT]

First thing to do is dump out all of that old fuel and rinse out the tank. Go through the carb, clean it. While apart,
remove the needle/lever/spring, and clean out the passage underneath it. Hold the saw body up to a light and make sure it is clear.
Then reassemble, and start out with fresh fuel mix.

 

[IowaDiver]

just to clarify... the saw was stored with fuel in it but I ran through 2 tanks of gas cleaning up the downed tree the day before the saw stopped running. I've ordered a new carb, fuel lines, filter and spark plug for $20... figured that is much easier than rebuilding a carb. I should have them friday and I'll give it a run this weekend.

 

[a. palmer jr.]

You can check your fuel line for kinking, right where it goes into the carb. It's also possible for rings to look good but be weak, thus low compression. I would check it with another gauge before tearing it all down though. When you rebuild one of these engines you should break it in before subjecting it to hard work. With all the tree cutting you did it would have been nice if you had two or three saws and alternated between them with the cutting especially if it's not broken in. Also possible the ignition module is acting up.

 

[heyduke]

just to clarify... the saw was stored with fuel in it but I ran through 2 tanks of gas cleaning up the downed tree the day before the saw stopped running. I've ordered a new carb, fuel lines, filter and spark plug for $20... figured that is much easier than rebuilding a carb. I should have them friday and I'll give it a run this weekend.

the problem may or may not be related to ethanol contaminated fuel but that's a good place to start in my experience. also a new carb is a good idea.especially with newer walbro and zama carbs. last time i had a similar problem with two ms250's, i found that my stihl dealer didn't even stock rebuild kits but had new oem carbs for $30 each, the reason being he had experienced problems with carbs rebuilt in his shop. i don't know if you can get ethanol free gas at any nearby stations but it would be worth the trouble if you can. just google "ethanol free gas" and you'll get a data base of all stations in the u.s. otherwise, for the hombres that bring in their usntartable saws, i recommend the cans of ethanol free fuel that are available of $6 per quart. it's a lot cheaper than having me get their saw s running agin, just like last year... good luck

 

[IowaDiver]

I'm anxious to get the new parts and see what the impact is. I use ethanol free fuel for all my small engines (lawn tools, motor boat, etc) which is why I felt safe leaving fuel in the tank between uses. I typically use the saw about every other month since we have a heavily wooded lot and during hurricane season we often get limbs or trees that need cutting up. I've run about 6 or 7 tanks of fuel through this saw since the rebuild and then another 2 tanks of fuel this during the storm, so I felt that it was pretty well broken in prior to that use. I have a Husky 445 that I use for smaller diameter cutting which fortunatly was on standby for the storm clean up.

I'll let you know how it turns out... since the carb and fuel lines are ordered I'm just going to swap them out and go from there with the trouble shooting. If I can drum up a buddy with a compression guage I'll double check the accuracy of my guage to see if it has any false reading.

 

[HarleyT]

just to clarify... the saw was stored with fuel in it but I ran through 2 tanks of gas cleaning up the downed tree the day before the saw stopped running. I've ordered a new carb, fuel lines, filter and spark plug for $20... figured that is much easier than rebuilding a carb. I should have them friday and I'll give it a run this weekend.

Not too excited about that purchase, I don't like the china crap.....

 

[ANewSawyer]

I bought a $15 one for my EB802. I have been meaning to post a review just haven't got to it. The chicom carb looked good inside, except that it the internal screen wasn't seated right. It was cockeyed. Some metal flash in the internal caveties but no voids. I plan to rebuild the oem carb but just haven't got to it.

 

[a. palmer jr.]

I've used a few of the China carbs and haven't had any trouble with any of them yet.

 

[HarleyT]

carb, fuel lines, filter, and spark plug for $20? All great quality eh? all of the china carbs are great?
Fuel lines????? Plugs?????
Would you use those parts if you fixed saws for a living?

 

[a. palmer jr.]

It would depend on what the customer wanted. Sometimes they want to go cheap.

 

[ZeroJunk]

carb, fuel lines, filter, and spark plug for $20? All great quality eh? all of the china carbs are great?
Fuel lines????? Plugs?????
Would you use those parts if you fixed saws for a living?

Aren't the Stihl OEM carbs made in China now ?