Stihl 038 identify question

[Jacob martell]

Hi, I bought a saw with no covers, I called stihl to see what kind of saw it was and with the part numbers off of the unit we determined that it was a 038

Now my question is how do i tell my bore size to see which model of a 038 it is. Is there a stamp on the cylinder? I have never taken one apart before but for $20 I paid for the saw it would be a good learning experience.

any help is appreciated

 

[scottr]

You can remove the muffler and measure the cylinder .

 

[Sam R]

The serial number should be etched on the front probably under or near the muffler. The dealer ought to be able to ID it with that.

 

[Chainsaw Jim]

It'll have a number cast into the cylinder telling you the bore size. On one side or the other you should see numbers like these...

48mm bore 036...

50mm bore 372xp...

56mm bore 056 mag II...

The angle of the exhaust can make an accurate measurement challenging.

 

[Jacob martell]

You can remove the muffler and measure the cylinder .

how do I measure it with just the muffler off?

 

[Chainsaw Jim]

If the angle of the exhaust isn't too steep you can use the depth probe on a set of calipers. Use the front of the piston to hold the calipers up against.

 

[scottr]

You can use a precision 6" scale . You can use a popsicle stick . A green twig .

 

[Jacob martell]

If the angle of the exhaust isn't too steep you can use the depth probe on a set of calipers. Use the front of the piston to hold the calipers up against.

I'm going to give this a try, the 2 screws holding the back part of muffler are pretty tight not sure how to get them off without breaking. Also the front oil tank has a crack in it and is leaking, do you guys think this is worth the repair? no covers on it also and no brake handle.

 

[Sam R]

Your oil tank is crack is bad news. If you can source a new side for it you'll have to split the CC to replace it.
A lot of the time those muffler bolts are tight, you should be able to get it off with a 1/4" drive ratchet and some PB blaster. If it's too tight for that, well, I'll let someone else chime in.
It sounds like you have a lot of parts you'll need to source. I guess it just depends on how bad you want to get it running. Is the piston seized inside the cylinder? Once you can get a good look at things through the exhaust you might have a better idea how much effort it'll take.

 

[Jacob martell]

Your oil tank is crack is bad news. If you can source a new side for it you'll have to split the CC to replace it.
A lot of the time those muffler bolts are tight, you should be able to get it off with a 1/4" drive ratchet and some PB blaster. If it's too tight for that, well, I'll let someone else chime in.
It sounds like you have a lot of parts you'll need to source. I guess it just depends on how bad you want to get it running. Is the piston seized inside the cylinder? Once you can get a good look at things through the exhaust you might have a better idea how much effort it'll take.

The saw actually runs good, 140psi compression and starts on first pull. So its a toss up but I only paid $20 for it so not into it too deep right now

 

[Sam R]

Interesting, and that is good news. I bet you can find yourself the bar cover, top cover and any other missing pieces if you look hard enough. I'd really scope out the piston/cylinder via the exhaust port. Runs doesn't mean not scored up. Also the oil tank crack will require remediation sooner than later if you actually intend to cut wood with it. Because I'm guessing right now your chain oiler probably doesn't work too well.

 

[Jacob martell]

Interesting, and that is good news. I bet you can find yourself the bar cover, top cover and any other missing pieces if you look hard enough. I'd really scope out the piston/cylinder via the exhaust port. Runs doesn't mean not scored up. Also the oil tank crack will require remediation sooner than later if you actually intend to cut wood with it. Because I'm guessing right now your chain oiler probably doesn't work too well.

Today I cleaned up the coil line and put it back together, the saw will start and run if the throttle is pulled, if i let the throttle go it will die right away, could this be an issue with the coil? when I reinstalled I gapped it with a business card

 

[Sam R]

Is it an electronic ignition? If so I'd feel safe saying almost definitely that's not the issue. If it's points, you'll have to ask someone with experience on those. The business card air gap method is tried and true.
No, chances are you have an air leak somewhere. Do you have the ability to pressure/vacuum test the crankcase, hoses, fuel tank, etc? Specifically the little rubber elbow that connects the carb to the cylinder, the oil seals or the crankcase itself may have a crack are places I suspect of having an issue.
Other basics, what condition are the air & fuel filter in? How does the spark plug look? If you get the muffler off, a look at the piston & cylinder could aid in your diagnosis.
Finally, your carburetor may have issues. If it's just dying at idle it could mean that the inlet need or inlet control valve are sticking or worn. One way to test this is to pressure test the inlet fitting of the carb to about .8 bar or roughly 10 psi. If it holds steady then at least you'll know it's sealing.