Need Help with Stihl 025

[Oby1]

Hello,

Saw stopped suddenly, acted like it lost ignition. Through trial and error, realized it still had spark. I was told by a technician it most likely was a fuel problem, either cracked fuel line, plugged filter, or plugged carburetor, possibly a plugged spark arrestor in muffler.

Spark arrestor wasn't plugged. Found a new replacement carb, put that on, replaced the fuel line and tank filter with new parts. Used one full turn out on both H and L adjusting screw on carb to begin. Saw will start using raw fuel poured in carb but I can only keep it running by putting my thumb over the butterfly valve on the carb and continuously adjusting the flow. That only works for about 30 seconds before it dies. It seems to get fuel from the tank, fuel poured in carb wouldn't last that long. Saw will not start without raw fuel poured in carb. Saw runs at high speed and will quit when it slows down. I don't know about compression since I don't have a compression tester but it seems to have similar resistance as before when pulling the starter cord. New spark plug is installed.

Thanks for any advice!!

 

[Bermie]

Sounds stupid, but is your idle turned high enough?

You say you 'found a new replacment carb'...new like direct from the dealer or picked up from somewhere else? The diaphragm or impulse line might have issues.

 

[Oby1]

Thanks for the reply. I don't know anything about these small carbs. The carb I got was an online purchase (new old stock) so it could have issues. How do I adjust this carb? I presume the L is the idle, when I screw the needle out from being set tight am I increasing the idle or decreasing it? Can you give me a basic overview on how to properly set the carb? Both the H and L settings?

Regarding the impulse line, I can't find any other line going to the carb other than the fuel line from the tank. Are they one and the same? If so, I already put on a new one as well as a new filter in the fuel tank.

 

[RDT]

Did you adjust the carb at all or just put it on. The high and low needles on the carb should be one full turn out from closed.
Turn both screws clockwise gently until they stop, Then turn them both counter clockwise 1 full turn out . This will good place to start from.

 

[Oby1]

Yes, that is exactly what I did to begin with before attempting to start the saw after putting on the new carb. One full turn out from snug on both.

 

[RDT]

Does your model have the easy start ( primer Bulb ) on the handle.

 

[Oby1]

No primer bulb.

 

[RDT]

You could have a carb boot problem (cracked), a bad impulse hose(cracked), I think you have to take the handle assembly off on that model to get to the impulse line.It runs from the engine to the back of the handle . The impulse line is what runs the diaphram in the carb to pump the fuel.

 

[Lakeside53]

Check under your handle (you'll need to remove a few screws to get it to move enough) - and see if your impulse hose has come off the connector.

 

[Oby1]

Thank you RDT and Lakeside53, I will check those items and get back with a reply.

 

[SawTroll]

I'd prefere a Wild Thingy to an 025/250, at least the plastic is a bit sturdier, but that's just me......

The overall quality difference is not much to speak of, and all the people I know that has a 250 (3) are complaining - I set the saws right, and then they go bad again........

My Partner 351 aka Poulan 2150 did much better.

 

[WRW]

I'd prefere a Wild Thingy to an 025/250, at least the plastic is a bit sturdier, but that's just me......

The overall quality difference is not much to speak of, and all the people I know that has a 250 (3) are complaining - I set the saws right, and then they go bad again........

My Partner 351 aka Poulan 2150 did much better.

Did you come here to help, or just to badmouth other peoples saws? With all the satisfied users of the 025/MS 250, I wouldn't be bragging that the three that I worked on were unsatisfactory.

 

[SawTroll]

Did you come here to help, or just to badmouth other peoples saws? With all the satisfied users of the 025/MS 250, I wouldn't be bragging that the three that I worked on were unsatisfactory.

They all started out bad, from a "box-store", but they work OK when I use them, but for some reason that I don't know they go bad again when they leave my hands....

..I believe they just are a bit more finicky than some other saws - most of the trouble is about starting.

 

[Oby1]

Ok, took the saw completely apart this afternoon (it needed a good cleaning). I found the location of the impulse hose, it is behind the carb and the handle assembly, you can't see it with just the carb off. The impulse hose and the boot to the carb were both supple with no apparent cracks that I could see. Impulse hose appeared to be attached, not loose. I rolled them around and even stretched them a bit to see if there were any hidden cracks. So I cleaned everything up and put it all back together.

I double checked the carb settings, turned the needles until they were set and backed them off one full turn. Tried to start the saw. Had to pour gas into the carb, after a couple of times of doing that with the saw running for a short few seconds the carb appeared to be primed, but it still took raw fuel to get it running for any length of time. Takes a lot of pulls to get it to fire, but once it does I can regulate it somewhat with the butterfly valve and my thumb over the air intake. I turned the L needle out one quarter turn more and it seemed to do better but not much. At this point my arm and side were tired from pulling the starter so I'm done for today.

I now understand the diaphram of the carb operates from the vacuum of the crankcase. If the rings were bad on the piston, or the cylinder wall was scored (looked ok from what I could see through the intake and exhaust) could that create a lack of vacuum to operate the diaphram in the carb?

By the way, I think my 025 is a fantastic machine even with the problems! It has (had) a lot of power and it is light weight and it has served me very well for a number of years now. I can cut wood all day and not be overly weary. I've been thinking of buying an 029 wood boss, but I don't like the extra weight. I would like to get this 025 running and use it as a occasional trim saw.

Thanks for all the help so far!

 

[Lakeside53]

They all started out bad, from a "box-store", but they work OK when I use them, but for some reason that I don't know they go bad again when they leave my hands....

..I believe they just are a bit more finicky than some other saws - most of the trouble is about starting.

It's either you or your wacky gas. Millions of them is the USA start and run just fine...

 

[windthrown]

Sounds like my 210 here last week. After reading a similar thread about a similar saw, and Lake's recommendation on testing and replacing the impulse hose... I replaced the impulse hose and it is running fine now. bowdown: All Hail Lakeside!) Before, it started, but would not stay started. Wanted to be flooded or starved for air to stay alive.

I would also blow out the impulse hose connector on the engine side and through the carb. To do that, pull the carb off and put an air compressor nozzle (or Dust-off air can nozzle) onto the little impulse inlet hole to the right of the intake boot and tap the compressor lever a few times. Then blow the carb out through the hole that connects to the impulse line. It will blow back through to the gas intake. Make sire that the carb seal is not creating an air leak at the inpulse hose connection (not folded over on itslef or torn). Also tighten the carb down good to prevent air leaks.

Other than that... I also have a DOA 250 parts saw that did not wanna start either. Bad compression due to really bad scoring. Easy to tell. Even my 210 has way more pull-back on the starter rope than the DOA 250. If it has a good pull on the starter rope, it is probably OK compression wise. If it is easy... pull the plug or better yet, the muffler and look at the rings and cylinder for scoring. Also all Stihls will not stay lit long if there are cracks in the gas line. Also on a 250 you would check the gas vent, but there isn't one on the 025.

 

[Oby1]

Thanks for the tips Windthrown. I will get an impulse hose and replace it. Certainly worth a try, would be a cheap fix. I didn't see any scoring but can't really see the whole cylinder through the intake and exhaust.

 

[04ultra]

I'd prefere a Wild Thingy

Yup Wildthingy is King of the refurbished saw's!!.......





.

 

[windthrown]

Thanks for the tips Windthrown. I will get an impulse hose and replace it. Certainly worth a try, would be a cheap fix. I didn't see any scoring but can't really see the whole cylinder through the intake and exhaust.

If you go in through the exhaust port and use a mini Maglite flashlight, you can usually see enough in there. Slide the piston up and look at the sides of it and the rings. Then slide it down and look at the cylinder. If you have small fingers you can poke one in and feel the sides of the cylinder wall. Scoring is pretty obvious when it is bad. Light line scratches are common and usually not an issue. Be careful in there, the edges can be sharp!

I forget if you mentioned it or not, but if the spark screen in the exhaust is clogged up, it will cause a similar effect of running really crappy.

 

[windthrown]

Yup Wildthingy is King of the refurbished saw's!!.......

.

The SawGod has spoken!!!!

Rumble...