Stihl 038AV - rebuild

[Friggs]

Hello all,

First time here...

I own a Stihl 038 which I bought new sometime in the early 1980's. It has loads of miles on her and still runs good but a little hard to start due to the lack of compression. Once she runs she will go for hours.

I would like to rebuild her and I'm wondering should I buy a cylinder and piston kit or should I just buy rings and gaskets. I know I should check the cylinder for wear and see if the cylinder has gone over.

I think my saw has a 48mm bore and all I see is cylinder kits for super and mag 038 and nothing for 48mm.
If I go with 50mm or 52mm cylinder kit will I need to upgrade my carb ?

Thanks...Friggs

 

[Mad Professor]

Hello all,

First time here...

I own a Stihl 038 which I bought new sometime in the early 1980's. It has loads of miles on her and still runs good but a little hard to start due to the lack of compression. Once she runs she will go for hours.

I would like to rebuild her and I'm wondering should I buy a cylinder and piston kit or should I just buy rings and gaskets. I know I should check the cylinder for wear and see if the cylinder has gone over.

I think my saw has a 48mm bore and all I see is cylinder kits for super and mag 038 and nothing for 48mm.
If I go with 50mm or 52mm cylinder kit will I need to upgrade my carb ?

Thanks...Friggs

A 50mm super P/C is closer to a bolt on as the crankcase holes will line up. You may have to end mill the case to allow the base of the cyl to mount flush on the case, this is described in the 038 stihl service manual. This can be done with a end mill bit in a hand drill. Keep the fillings out of the case!

The next step up is the 52mm 038M P/C. I've put one on a super but never on an 48mm 038. It also should be doable and will give you the most power. Do a search on the chainsaw forum, I described the conversion. It involves slotting the mag cyl bolt holes to match the super case.

The carb may be smaller on the 48mm 038, I'm not sure. The super (50mm) I converted had a Tillston which was the same size as the latter Bings that came on the magnums. The conversion (super to mag) ran fine with either. I'm running a Bing.

You'll either want to mod the 038 muffler or get a OEM dual or triple port from a super/magnum. Lots on muffler mods in the chainsaw forum.

Whatever you do use quality parts. OEM is best but I can also recommend Tecomec.

P.S. replace the impluse line while you have the cyl off, check the intake boot for cracks, and maybe replace the crank seals.

P.P.S. WELCOME TO THE FORUM!

 

[Friggs]

Thanks M.P.,

I'm keeping my eye out for a 50mm jug & piston and will have to do a pressure test to see if I need other parts such as seals and stuff. I'll have to read up on the muffler mod for the 038.

Thanks again for the info.

Friggs