025 repair suggestions?

[Mitt]

Hi all,
I'm having a bit of a problem with my saw. It has spark and compression. When I add gas directly to the cylinder it fires right away. I looked to see if the rubber manifold between the carb and cylinder is cracked and that looks ok too. I looked at the impulse hose that goes from the carb to the cylinder. I took apart the carb (very clean and a little wet) So I dunno what to do next? Any suggestions?
Thanks for your time.
Mitt

 

[AdamL]

I've seen alot of clutch side crank seals fail on 021,023, and 025 series saws, what happens is over time the two front bolts holdiing the cyl down loosen and the seal begins to leak around the outside edge, a pressure test would tell you right away if the seal is bad. They do make a seal that can be pressed in from the outside but i've never had any luck with these seals lasting long, if thats the problem your better off getting the oem style seals that require a teardown of the engine to install.

 

[Mitt]

Hi Adam,
Thanks for replying!
I checked the cylinder pressure and it was at 125 after 5 pulls- but I must admit that I did not wait to see if it would hold.
I'll take a look.
Thanks again.
Mitt

 

[HimWill]

Try a new fuel filter,make sure the fuel line isn't kinked going to the carb and check that the tank vent is clear.

 

[Mitt]

tank vent has a screw in it. Maybe I'll just remove it.....?

 

[Rookie1]

Thats a compression test you did. Hes talking about pressurizing the crankcase to see if there are any seals or gaskets leaking. Welcome to AS too.

 

[Mitt]

So, for a pressure test what do I do? Hook it up to the compressor?
Thanks for the welcome.

 

[Rookie1]

Check this out. http://www.arboristsite.com/showthread.php?t=42768&highlight=poor Your welcome on the welcome

 

[Fish]

Hi all,
I'm having a bit of a problem with my saw. It has spark and compression. When I add gas directly to the cylinder it fires right away. I looked to see if the rubber manifold between the carb and cylinder is cracked and that looks ok too. I looked at the impulse hose that goes from the carb to the cylinder. I took apart the carb (very clean and a little wet) So I dunno what to do next? Any suggestions?
Thanks for your time.
Mitt

WOW.
Sounds like you need a new fuel line and a "proper" carb rebuild/cleaning.

 

[AdamL]

a fuel line could be another possiblity. I guess I jumped at crank seals since if the saw was apart enough to check the impulse and intake elbow I figured a bad fuel line would be quite obvious....good thing to mention, thanks FISH.

 

[HimWill]

tank vent has a screw in it. Maybe I'll just remove it.....?

No need to remove the screw from the vent.Remove the rear cover and check the vent by shaking the saw (like shaking a piggy bank) and watch for fuel coming out the vent.A good shake will put some pressure in the tank and some air and fuel should come bubbling out.Any cracks in the fuel line will usually show up too.
This series of saws,in my experience,has issues with the clutch-side crank bearing failing.The tell-tale signs of this failure is scoring on the intakeside of the piston.Look through the carb(or remove it) to get a look at the piston.The top of the piston will be pitted too,as the bearing spacer breaks up and the pieces are pulled through the engine and spit out the exhaust.Pull the muffler to get a good look at the piston top by shining a light through the spark-plug hole.

 

[Mitt]

HI Guys,
just thought I would bring this to a close. Pulled the cylinder apart and the clutch side seal was totally gone. (Bit of a gooey mess under the cylinder base. Maybe this could be used as a diagnostic clue in the future?) There are 2 types of seals for this style of saw. Smaller diameter and larger. Mine was the larger diameter. Unfortunately the local shop only had one seal. I would have preferred to replace both sides. Am re-assembling today. I feel confident that it shall work just fine.
Thanks again for all your help!
Mitt

 

[sefh3]

While your at put a set of rings in it while the cylinder is off of it. 120 is low but the saw will run. Make sure you didn't lean sieze the saw. I would replace both seals.

 

[Mitt]

Saw runs! What is "lean seize"? Not enough oil in the gas? I would have loved to replace both seals but there were none in town. The saw belongs to a buddy and I was getting tired of looking at the pile of pieces and worried that I would loose a screw or other important item. We'll see how she goes. In any case it was a new problem on a saw for me. Thanks for the help solving what was wrong.
M

 

[jamie101]

While she has been a pile of bits and only replacing one seal is not the way to go, saws require love and dedication, wait till the dealer could get the other seal and replace both. Cos i bet in a short time the other one will go and then its another strip down and rebuild for the sake of waiting a week or two. It could be even worse, cos we all know what bad seals can cause.

 

[YZEATER]

Saw runs! What is "lean seize"? Not enough oil in the gas? I would have loved to replace both seals but there were none in town. The saw belongs to a buddy and I was getting tired of looking at the pile of pieces and worried that I would loose a screw or other important item. We'll see how she goes. In any case it was a new problem on a saw for me. Thanks for the help solving what was wrong.
M

lean seize is too much air compared to gas mix. you mix your gas and oil per what's on the bottle, and then tune your saw to that.