Stihl 025

[mdavisfps]

Hi,
I'm a homeowner, not a professional, and cut down & cut up approx. 4-5 trees per year (14"-28" mixed oaks).
Some years I don't cut any.

Anyhow, I have a Stihl 025 which starts easy, runs well, and is no problem starting back up when hot -- UNLESS I let it sit for about 10-15 minutes after having run it for awhile. Then it won't start or even fire no matter what setting I try (hot/cold switch) or how many times I crank it.
However, if I remove the spark plug and crank it a few times and then replace the spark plug, it will start with the first pull (on the hot setting) and then run well after that. I thought maybe I had flooded it while trying earlier to get it to restart, but the spark plug is dry.

The saw is 25 years old. The Stihl dealer says that at that age it could be any number of things, e.g., a fuel diaphragm, or other parts of the carburetor, or the fuel line, etc.. Cranking it without the spark plug causes it to crank a lot faster, which probably corrects the problem, which then allows it to restart. He says that I could spend $50-$100 dollars to repair it, but if it was him, he would replace it with a comparable saw, like the MS 250. He says that if I've gotten 25 years out of it, then I've gotten my money's worth, and I see his point.

I'm was just wondering, however, if someone on this site might know something more specific in regards to the symptoms of this problem.

P.S. Love this site and those of a number of its members. I visit this site and the others often to learn how to cut safely and efficiently.
Thanks,
Mark

 

[Z'sTrees]

Your dealer is right that you've gotten your money out of the saw, but he probably would rather sell you a new one for $300 than have to fix yours for $100...
I would wonder if it's some sort of vapor lock issue or possibly the coil. Sometimes a failing coil can be exacerbated by heat.
There are a few guys on here that really know there stuff but you may want to check out another site that is much more chainsaw focused. Starts with an A and rhymes with arboristsite.

 

[Merle Nelson]

You've gotten your moneys worth when you decide to retire the saw in my opinion.

Don't think it will be the coil this time or it would stay non starting when hot and having sat.

One more check I can think of would be to dribble a few or five drops of fuel into carb opening when it is doing this. If it popped and wanted to run it would be a starving for fuel issue - which dry plug points towards.

I'm not sure where it will go from there as I only know very basic saw diagnosis. Someone will be along shortly who can help you, or that other site will have people who readily can.

One thing I do know is that saws are not done JUST because of age. I run a particular model of climbing saw that is at a minimum 27 years old and some of my older ones are 37 years old or so. They are different than new but not done.

 

[mdavisfps]

Your dealer is right that you've gotten your money out of the saw, but he probably would rather sell you a new one for $300 than have to fix yours for $100...
I would wonder if it's some sort of vapor lock issue or possibly the coil. Sometimes a failing coil can be exacerbated by heat.
There are a few guys on here that really know there stuff but you may want to check out another site that is much more chainsaw focused. Starts with an A and rhymes with arboristsite.

Thank you, Z'sTrees.
There was something in the back of my mind about vapor lock, but the dealer said "no, that doesn't happen". Guess I could just crack the filler cap next time to see if that had any effect.
I tried "arboristmight" and "arboristright", but couldn't find that other site.
Mark

 

[mdavisfps]

You've gotten your moneys worth when you decide to retire the saw in my opinion.

Don't think it will be the coil this time or it would stay non starting when hot and having sat.

One more check I can think of would be to dribble a few or five drops of fuel into carb opening when it is doing this. If it popped and wanted to run it would be a starving for fuel issue - which dry plug points towards.

I'm not sure where it will go from there as I only know very basic saw diagnosis. Someone will be along shortly who can help you, or that other site will have people who readily can.

One thing I do know is that saws are not done JUST because of age. I run a particular model of climbing saw that is at a minimum 27 years old and some of my older ones are 37 years old or so. They are different than new but not done.

Thank you, Merle, for your suggestion. Especially "thanks" for the comments about age itself.
Mark

 

[colb]

Your dealer is right that you've gotten your money out of the saw, but he probably would rather sell you a new one for $300 than have to fix yours for $100...
I would wonder if it's some sort of vapor lock issue or possibly the coil. Sometimes a failing coil can be exacerbated by heat.
There are a few guys on here that really know there stuff but you may want to check out another site that is much more chainsaw focused. Starts with an A and rhymes with arboristsite.

My dealer says they don't make much on the sales of smaller saws. The repairs keep them going just as much. I think he's on the level. But, I'd suspect that that saw has more life in the hands of someone willing to repair it themselves. I had to retire an 025 last year because the housing melted into an amorphous glob. It was my go-to ground and negative blocking saw for the two years I had it. Btw, don't get the 250c homeowner model. I got two for free and the bar length adjuster is a pain in the arse. Bueno suerte!

 

[mdavisfps]

My dealer says they don't make much on the sales of smaller saws. The repairs keep them going just as much. I think he's on the level. But, I'd suspect that that saw has more life in the hands of someone willing to repair it themselves. I had to retire an 025 last year because the housing melted into an amorphous glob. It was my go-to ground and negative blocking saw for the two years I had it. Btw, don't get the 250c homeowner model. I got two for free and the bar length adjuster is a pain in the arse. Bueno suerte!

Thanks, colb, for the response. The Stihl dealer I go to was the one that sold me the saw back in '91. I trust him and don't believe he would try to sell me something just for the sake of selling it. Regarding the 250cc, I know there's a lot of conflicting opinions out there about it (just like every saw). No need to start another thread about it, I guess. Thanks for the input about the bar length adjuster, though.
Mark

 

[Jackjcc]

It sound like it is flooding. Heat will cause expansion and pressure to build in the tank. The tank vent may not be functioning correctly so pressure builds which forces fuel into the carb. This could cause fuel to seep through carb through old gaskets and poor seals. The fuel that seeps through would end up pooling in the engine.

Based on what you said with taking the plug out and pulling it over, you are clearing a flooded condition.


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[mdavisfps]

It sound like it is flooding. Heat will cause expansion and pressure to build in the tank. The tank vent may not be functioning correctly so pressure builds which forces fuel into the carb. This could cause fuel to seep through carb through old gaskets and poor seals. The fuel that seeps through would end up pooling in the engine.

Based on what you said with taking the plug out and pulling it over, you are clearing a flooded condition.


Sent from my iPhone using Tapatalk

Thanks, Jackjcc.
Questions:
1. This happened twice the other day. The first time the plug was black, but not wet. The second time, the plug was dry (gray). Could this still be a flooded condition?
2. Does the pressure build up to excessive levels only after the engine is shut down ... not when it's running?
3. Would cracking the fuel cap to relieve pressure when the condition occurs work, do you think?
4. Are we talking about the tube with the spring-like thing in the end of it?

Mark