So many 038’s

[Permit Number 038AVSP]

Hello out there, this is my first post, here goes!
I have an older Stihl 038 AV Super Pro which I am looking at refreshing a little. It’s a great saw that for a bigger guy is great for felling and bucking almost anything. Problem is the serial number doesn’t register with Stihl so I guess it’s older than the database. I’ve seen posts with info and specs on the 038, 038AV, 038 AV Super and the 038 Magnum, but never an 038AV Super Pro. It’s one which was built in West Germany if that helps at all. If any of you Stihl wizards out there have any info that can help me with the specs it would be much appreciated as I would like to order a top end kit and there are different bores. If possible to increase the jug size I would at the same time.
Thanks

 

[Mad Professor]

As far as I know same as 038 super, 50mm bore.

You can put a 52mm 038 magnum cylinder on it but it is not a bolt on, but not too much work. Threads here on how to do it, do a search. Parts are available if you want to use the 038S cylinder (piston/rings)

Since Tecomec went Chi-Com the only 038M cylinder I'd use is OEM, good used or new (new OEM P/C is kit is ~$300). Meteor lists 038M pistons but not cylinders?

If you find a good used OEM 038M cylinder, OEM piston is ~$90, meteor ~$40.

Others have luck, or frustration, with Chi-Com cylinders/pistons.

It's worth opening up the dual port muffler. If you go to 038M cylinder, widen the muffler entrance to match the ex port too.

Set the "squish", clearance of piston top at TDC to cylinder combustion chamber, ~0.020".

Worth looking over clutch, which is way overbuilt, and the oil pump/pump drive gears (leaks). Unless wore out you can get gaskets/seals for oil pump.

All rubber parts/seals/filters/carb kit. Gasket set comes with crank seals.

True up bar rails, new drive sprocket/chain.

Check AV mounts, replace if needed.

 

[Permit Number 038AVSP]

Thanks for your help, still not 100% sure of the bore and stroke, I guess I’ll have to tear it down and measure everything. Still runs and cuts fine, but 30 years and a couple hundred cords old. Cylinder is fine, so I think I’ll just break the glaze and replace the piston and rings. I’ve looked after the saw so the rest of the things you have mentioned have either been done or don’t need to be done. Kinda wish Stihl would have one model for each number instead of two or three.

 

[stilh036prohog]

I miss mine. Just run it rich.

 

[Mad Professor]

Thanks for your help, still not 100% sure of the bore and stroke, I guess I’ll have to tear it down and measure everything. Still runs and cuts fine, but 30 years and a couple hundred cords old. Cylinder is fine, so I think I’ll just break the glaze and replace the piston and rings. I’ve looked after the saw so the rest of the things you have mentioned have either been done or don’t need to be done. Kinda wish Stihl would have one model for each number instead of two or three.

All the 038 versions used the same crank/stroke. The 038 48mm bore (62cc), super 50mm bore (67cc), and magnum 52mm bore (72cc).

Meteor has 50mm pistons that come with Caber rings. I'd get a gasket set and do crank seals unless those have been replaced. Gasket set is ~$10 cheaper than buying the seals separate.

You can check piston/cyl clearance if you consider just doing rings, new is ~0.002"