Grapetree
ArboristSite Lurker
Nice Thread and read,... makes me want to break own my MS 180 C and see why it will not start ...
Stihl 039 Rebuild
- Thread starter Brewz
- Start date
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Box turned up in the mail today with all my new bits in it.
Opened it up and found that I only ordered 1 bearing
and that one bearing is a no name brand that doesn't feel very smooth
I will go to the local bearing place and get myself a couple good quality bearings.
1 bearing........ I still cant believe I only ordered 1 bearing
Opened it up and found that I only ordered 1 bearing
and that one bearing is a no name brand that doesn't feel very smoothI will go to the local bearing place and get myself a couple good quality bearings.
1 bearing........ I still cant believe I only ordered 1 bearing
Grapetree
ArboristSite Lurker
Hello Brewz, can you tell me how I can know before disassembly of the saw what wrist pin size the saw requires ? either a 8 mm or a 10mm
I want to order the correct piston and pin for a future repair.. or do I have to take it apart and measure it ?????
I want to order the correct piston and pin for a future repair.. or do I have to take it apart and measure it ?????
Mine measures 10mm
I just ordered a piston kit and it came with 49mm piston, 10mm wrist pin, 2 rings and wrist pin retaining clips
I had to buy a new earring seperately
I went and dug through all the bits I got for the saw.
I recently replaced some parts on my Stihl 066 Magnum, and I used OEM parts as when it works, it works hard and I dont want a $10 hose stopping the show.
I dont use the 039 I am rebuilding for anything major. Its mainly a liming and small timber saw, so I went cheap and bought some chinese parts.
I doubt I will again. They are mostly rubbish!
The piston looks good. I bought good Caber rings to go in it.
The hoses are a different story.
First up is the oil hose that comes out of the tank and has to bend at 90 deg around a corner to connect to the oil pump outlet.
The OEM hose bends and keeps its shape.
The Cheap Chinese one kinks before it bends as it is much thinner
The intake hose between the carb and the can is no better
The OEM is moulded to the shape of the intake
The Chinese copy is not and would restrict airflow
3rd shot shows the after market hose blocking the sides of the intake and exposing the flat edge of the top
The OEM hoses are still in good nick so I will be fitting them back onto the saw.
I ordered the cheap ones to see what they were like and I am not impressed.
I recently replaced some parts on my Stihl 066 Magnum, and I used OEM parts as when it works, it works hard and I dont want a $10 hose stopping the show.
I dont use the 039 I am rebuilding for anything major. Its mainly a liming and small timber saw, so I went cheap and bought some chinese parts.
I doubt I will again. They are mostly rubbish!
The piston looks good. I bought good Caber rings to go in it.
The hoses are a different story.
First up is the oil hose that comes out of the tank and has to bend at 90 deg around a corner to connect to the oil pump outlet.
The OEM hose bends and keeps its shape.
The Cheap Chinese one kinks before it bends as it is much thinner
The intake hose between the carb and the can is no better
The OEM is moulded to the shape of the intake
The Chinese copy is not and would restrict airflow
3rd shot shows the after market hose blocking the sides of the intake and exposing the flat edge of the top
The OEM hoses are still in good nick so I will be fitting them back onto the saw.
I ordered the cheap ones to see what they were like and I am not impressed.
Picked up my tube of Motoseal 1 today and spent this afternoon putting the 039 back together.
I made sure all the bearings had a bit of 2 stroke oil on them.
It all went back together really nice
I checked the squish and it measures 0.038" and the compression tester registered 140 psi. Not the best but not much choice with this saw. Its not intended to be any power or rev monster, just a reliable firewood saw.
I will check the compression again after a tank or 2 of fuel to see if it improves when the rings bed in.
All back together, filled with oil and fuel, new 16" 325 bar fitted, I set the H and L screws on the carb to 1 turn each and started pulling the cord.
Nothing.
Checked a few things and it all looked perfect. Tried again and nothing. Flatly refused to fire up.
I checked the spark and it was sparking fine and it was then I noticed all the fuel. The muffler and engine was full of fuel.
I drained the muffler and the motor, dried it all out and wound the H and L screws back to half a turn open each.
Tried again and got it to fire up.
Wound out the LA screw and richened it up till it idled nice.
Gave it a few mild blips of the throttle and it revs nice.
That's when I got in trouble for playing with a noisy saw in the garage just after the kids had gone to bed
Turned it off and will play with it on the weekend
I am a happy man!
I made sure all the bearings had a bit of 2 stroke oil on them.
It all went back together really nice
I checked the squish and it measures 0.038" and the compression tester registered 140 psi. Not the best but not much choice with this saw. Its not intended to be any power or rev monster, just a reliable firewood saw.
I will check the compression again after a tank or 2 of fuel to see if it improves when the rings bed in.
All back together, filled with oil and fuel, new 16" 325 bar fitted, I set the H and L screws on the carb to 1 turn each and started pulling the cord.
Nothing.
Checked a few things and it all looked perfect. Tried again and nothing. Flatly refused to fire up.
I checked the spark and it was sparking fine and it was then I noticed all the fuel. The muffler and engine was full of fuel.
I drained the muffler and the motor, dried it all out and wound the H and L screws back to half a turn open each.
Tried again and got it to fire up.
Wound out the LA screw and richened it up till it idled nice.
Gave it a few mild blips of the throttle and it revs nice.
That's when I got in trouble for playing with a noisy saw in the garage just after the kids had gone to bed
Turned it off and will play with it on the weekend
I am a happy man!
What brand were your substandard parts? It would be nice to know so I and others might stay away from them.
No idea what brand. They were "quality import" parts.
I ran the saw up again this morning. Starts much easier than it bid before the rebuild with noticeably more compression on the rope pull.
Set the idle and max revs and it runs sweet!
Previously, I could not get the idle to hold revs. No matter what I did, it would want to drop revs and die. It was worse when it was sat on the ground.
This morning it happily vibrated its way around on the garage floor at idle for 5 minutes without an issue.
The only thing I am concerned with is the way I fitted the oil seals on the crank shaft.
I put them in after I had the motor back together and they didn't want to go in. I should have sat them on the shaft and clamped them in place like the crank bearings.
Oh well...... if they give me strife I will have to strip it again and change them
Thanks for all the help folks
I ran the saw up again this morning. Starts much easier than it bid before the rebuild with noticeably more compression on the rope pull.
Set the idle and max revs and it runs sweet!
Previously, I could not get the idle to hold revs. No matter what I did, it would want to drop revs and die. It was worse when it was sat on the ground.
This morning it happily vibrated its way around on the garage floor at idle for 5 minutes without an issue.
The only thing I am concerned with is the way I fitted the oil seals on the crank shaft.
I put them in after I had the motor back together and they didn't want to go in. I should have sat them on the shaft and clamped them in place like the crank bearings.
Oh well...... if they give me strife I will have to strip it again and change them
Thanks for all the help folks
fearofpavement
Trying them all
Yeah, if you forced the seals in after the engine was assembled, you very likely have or will have an air leak there. Pressure test it and see if it's leaking. If not, you may be ok if they're in the proper position now. Not sure how you even got them in, that must've been a battle...
I usually do my 290, 390 builds a little differently. I put the engine all together and bolt the bottom end on the engine and let it sit overnight so the sealer can dry, (I use spacers and stock bolts) take the bolts back out and install it in the saw the next day. Takes a bit longer but seems to work for me.
They make two different type of crank seals for your saw. One type is for when you have the clamshell split (i.e. total rebuild) and the other is for replacing the seals while the engines is assembled and in the saw body.
The way I do it is a little more difficult to get the engine in the saw because of tight clearance but a little patience helps.now you tell me.
Stihlofadeal64
Addicted to ArboristSite
This is correct. There is a soft seal that is used for when the engine is completely disassembled and one used for when the engine is assembled like yours pictured. Honestly I never assembled one of these without a thin coat of sealer on the clam shell sides in the area where the seals mate. Extra insurance against a potential air leak that may kill the saw. Everything you pictured looked very clean. Congrats on the experience building it.
I think I had soft seals too as they were rubbery and not as solid as the ones I used to install in Electric motors and gearboxes.
I want it to be right so will order a couple more seals tonight and fit them in properly with some sealant for insurance.
I took it out to run it in some timber today. It goes like stink!
Ran a 16" Oregon bar, 325 063 semi chisel chain and an 8 pin sprocket. Tuned it to idle at 2800 RPM and spin to 12400 no load.
In 10 - 12" thick hardwood rounds, it steamed through with ease. Definitely making more power than it did before.
Very happy!
Will get the seals and fit them properly.
Cheers
I want it to be right so will order a couple more seals tonight and fit them in properly with some sealant for insurance.
I took it out to run it in some timber today. It goes like stink!
Ran a 16" Oregon bar, 325 063 semi chisel chain and an 8 pin sprocket. Tuned it to idle at 2800 RPM and spin to 12400 no load.
In 10 - 12" thick hardwood rounds, it steamed through with ease. Definitely making more power than it did before.
Very happy!
Will get the seals and fit them properly.
Cheers
Terry Syd
Addicted to ArboristSite
The worn original crank bearings were likely the cause of the idle problem, especially with the symptoms of when the saw was on the ground. With the saw in you hands, your hands work as a sort of anti-vibe, but on the ground the crank can bounce around more easily in the worn bearings and pick up a leak past the seals.
The cover on the muffler is the restriction on that series of saws. You may have made some big holes under the cover, but the exit hole is controlling the flow. You can reshape the cover to open up the exit. I used a butane torch to heat mine and then slowly reshaped it with a small ball peen hammer.
The OP posted a pic of his muffler cover in post#17. I've not seen one like that before but it looks fairly unrestricted compared to what I'm used to seeing and maybe what you're referencing, Terry. Is that style cover common in OZ?
