Stihl 025

[doc874]

Rec'd an 025 i bought from BB the one with the oil pump burnt right out of the case and the case melted. Well i tore it down tonight and found someone had tried to replace the piston/rings with a new one which would have been fine if they had not used so much gasket maker. They had put the gasket maker along the pan edges and also on the oil seals and track and on the bearings and their track as well. I guess someone tried to save money but in the end lost the use of their saw ( some people never learn :bang: :bang: ). Would have been cheaper in the long run to take it in for repair. The cylinder and piston are in excellent shape, the oil seals and bearings look ok as well. The other problem i found was the timimg key had gotten sheared off and now a piece is stuck to the flywheel ( or is this a part of the flywheel?? ). I have a used case so i believe the saw is salvageable. It took me about an hour to pick the gasket making stuff off the oil seals and bearings ( what a mess. ) Here are some pics after i cleaned the piston etc...

P.s. Forgot to mention, i'm working on the wifes oak dining room table. Lol. Pls don't tell!


Doc

 

[chuckiehow]

Hey Doc.....enjoyed reading about your 025 and seeing your work. We've got four of them (had five but one disappeared....stolen?) and I bought a used complete jug and piston w/seals and crank from E-bay for one of them. Hope it's not a ripoff as I sure need it. Will receive it in about a week. A friend replaced the crank seals in his 025 and they cost $44 (both) plus tax just for parts so I felt secure giving just a little more for the complete setup.

Still pulling my hair over another 025 that has bad carburation. I put a good carb on from our newest saw and it works 90% better but still acting like too lean of a mixture....and that's without adjusting between saws. I'll try a new fuel line and if that doesn't do it, the only other avenue is the crank seals.
I'm wondering if they go bad in stages. I'm getting an air leak somewhere and I've checked the carb/engine gasket (even gave it a little gasket sealer).

Keep sharing with us.
Thanks,
Howard

 

[Lakeside53]

Don't sweat the flywheel key. Degrease both the flywheel and the crank end, mark the CORRECT POSItION ON BOTH and just give the flywhele a nice tap to seat it. Then touque to the correct valve, making sure it doesn't move. The key is only for initial postioning - it has nothing to do with holding power.

 

[Justsaws]

I am always amazed at the effort people make in trying to use the entire tube of sealant on their saw. One saw =one tube, seems to be the thought behind so many "I will do it myself repairs". I took one Poulan apart because it locked up when the repairer tried to start it, he had used enough goo to do 10 saws. It was everywhere, even in the throat of the carb. and in the muffler. What a mess.

Your did a good job with the cleaning hopefully you will have a good 025 when you are done. Good luck.

 

[SmokinDodge]

Don't sweat the flywheel key. Degrease both the flywheel and the crank end, mark the CORRECT POSItION ON BOTH and just give the flywhele a nice tap to seat it. Then touque to the correct valve, making sure it doesn't move. The key is only for initial postioning - it has nothing to do with holding power.

Lake I was speaking with the local Stihl dealer about that very thing. He said he has tried it on a couple 056's and one 045 and it worked until he let off the throttle and the mass of the flywheel caused it to spin out of time. What have your results been on these saws with this method?

 

[Lakeside53]

It's been good. I did at least one 056, and many other saws. If a flywheel spins on a tapered shaft, the connection is bad and/or the torque value is incorrect (you'd be amazed how many don't use a torque wrench..) If all that's holding it is the key, there will be trouble... That's why the newer flywheels just have a weak "key" cast into them - no separate woodruff key. The cast numb has absolutely no shar strength... The connection must be very good - no rust, oil or crud.

 

[SmokinDodge]

Not doubting you a bit Lake, just wanted more info. I wouldn't hesitate a bit to do it. The "local" shop is good, the fella running it now bought the business from his father that had it 20+ years so they have plenty of experience. Just hard headed some times, which isn't always bad.

 

[doc874]

025

Don't sweat the flywheel key. Degrease both the flywheel and the crank end, mark the CORRECT POSItION ON BOTH and just give the flywhele a nice tap to seat it. Then touque to the correct valve, making sure it doesn't move. The key is only for initial postioning - it has nothing to do with holding power.

Thanks Lake. I will do that very thing. I believe i got a good saw now that its cleaned up abit.I still have some assembly to do like the oiler gear/clutch etc... I'll let you all know how it goes. Thank you for the info.

Doc

 

[doc874]

Hey Doc.....enjoyed reading about your 025 and seeing your work. We've got four of them (had five but one disappeared....stolen?) and I bought a used complete jug and piston w/seals and crank from E-bay for one of them. Hope it's not a ripoff as I sure need it. Will receive it in about a week. A friend replaced the crank seals in his 025 and they cost $44 (both) plus tax just for parts so I felt secure giving just a little more for the complete setup.

Still pulling my hair over another 025 that has bad carburation. I put a good carb on from our newest saw and it works 90% better but still acting like too lean of a mixture....and that's without adjusting between saws. I'll try a new fuel line and if that doesn't do it, the only other avenue is the crank seals.
I'm wondering if they go bad in stages. I'm getting an air leak somewhere and I've checked the carb/engine gasket (even gave it a little gasket sealer).

Keep sharing with us.
Thanks,
Howard

Hi Chuckiehow. Replace the fuel line. Check your carb bolts, impulse line and intake boot as well for small cracks etc... Also check torque on your cylinder bolts under the case its unlikely they loosened but one never knows. It may very well be the seals but adding gasket maker or goop won't fix it. Once all else has been ruled out ( cheaper way to go. ) It maybe neccessary to replace the seals. Good luck.

Doc

 

[doc874]

It's been good. I did at least one 056, and many other saws. If a flywheel spins on a tapered shaft, the connection is bad and/or the torque value is incorrect (you'd be amazed how many don't use a torque wrench..) If all that's holding it is the key, there will be trouble... That's why the newer flywheels just have a weak "key" cast into them - no separate woodruff key. The cast numb has absolutely no shar strength... The connection must be very good - no rust, oil or crud.

Hey Lake i don't have a shop manual for this 025 so, what is the correct torque on the flywheel bolt. Promise to use a torque wrench, as i'd hate to wreck my new addition, or any other saw. Thanks.

Doc

 

[Fish]

torque 021,023,025 flywheel nut
28 Nm
21 lbf.ft

 

[doc874]

025

torque 021,023,025 flywheel nut
28 Nm
21 lbf.ft

Thanks Fish.

Doc

 

[chuckiehow]

Hi Chuckiehow. Replace the fuel line. Check your carb bolts, impulse line and intake boot as well for small cracks etc... Also check torque on your cylinder bolts under the case its unlikely they loosened but one never knows. It may very well be the seals but adding gasket maker or goop won't fix it. Once all else has been ruled out ( cheaper way to go. ) It maybe neccessary to replace the seals. Good luck.

Doc

Haven't scheduled that long trip to get a fuel line yet but what I DID find was one of the bottom cylinder bolts that was loose about 3/4 turn. Will remove the handle tomorrow and check the fourth one. I'd have never thought of that possibility..! Haven't run it yet but that sure could have been the problem. It would suck air and cause it to run lean (fast) which it has been doing (plus it would die on idle). Just talking to myself here but thanks for mentioning that Doc.

 

[Lakeside53]

Haven't scheduled that long trip to get a fuel line yet but what I DID find was one of the bottom cylinder bolts that was loose about 3/4 turn. Will remove the handle tomorrow and check the fourth one. I'd have never thought of that possibility..! Haven't run it yet but that sure could have been the problem. It would suck air and cause it to run lean (fast) which it has been doing (plus it would die on idle). Just talking to myself here but thanks for mentioning that Doc.

Yes! and if they get loose enough, the seals spin... Use a torque wrench... break one off and you be in a pile of hurt!

 

[chuckiehow]

Yes! and if they get loose enough, the seals spin... Use a torque wrench... break one off and you be in a pile of hurt!

Thanks for that bit of wisdom Lake.

Looks like I'll have to get me one of 'them thar thingys' if I'm gonna be a Meck-A-Nik in my old age.

 

[mattinky]

Hey Joe, What did you ever find out about the "hole" in the oiler ? What did it look like on the burned up saw ? Still curious! Matt

 

[doc874]

025

No problem. I have learnt alot myself, from the gang here. You never stop learning, its what makes life great. Let us know how it goes.

Doc

 

[doc874]

Hey Joe, What did you ever find out about the "hole" in the oiler ? What did it look like on the burned up saw ? Still curious! Matt

Hey Mattinky. There is a plug for it, a small orange one. Looks like the top of a bic pen and for a Stihl product, not very well thought out. It has the potential to come out which i heard happens alot, not sure why Stihl did it this way other than to get access to the oiler tube should a blockage happen. I can get pics if you want.

Doc

 

[Lakeside53]

If you are talking about the plug to the left of the muffer (looking at the front), then it's so they can bore the oil passage. It comes loose rarely, but if it does I just use a soldering iron to melt it into place.

 

[doc874]

Hey Lake you have enlightened me again i guess during manufacturing the tube is solid and they drill it out during final processing stage?