Stihl 038: replace 50mm cylinder with 48mm cylinder-consequences?

student1 · Nov 22, 2005

Hi all,
my Stihl 038AV Super saw has a scored piston and cylinder. It was running well until it overheated--short story involving a dull chain and as strong operator. Now I have an offer for a used cylinder and piston from a 038AV. I understand that this is a bolt-on replacement with the only difference being that the old cylinder is 50mm and the new being 48mm. What will happen if I replace the old 50mm cylinder and piston with one that is 48mm. Will I need to replace the carb also or can I adjust it to work well with the "new" cylinder?

Cheers and thanks for your help.

Lawn Masters · Nov 22, 2005

Why go with the 48mm cyl when you could get the 52mm one that was on the 038MAG models? bring it up to the 72cc displacment.

student1 · Nov 22, 2005

Hi Lawn Master,
thanks for suggesting the 52mm instead. It is probably more power than I need but I am a strong believer in "bigger is better" so.....

Do I have to get a new carburator if I replace the 50mm cylinder with a 52mm cylinder?

Cheers and thanks again.

thompson1600 · Nov 22, 2005

You cannot change an 038 (48mm) or an 038 Super (50mm) top end with an 038 mag (52mm) top end. The cases are different. The 038 Mag takes a different crankcase than the other two.

Changing from 48mm to 50mm or vice versa is a bolt on change. You shouldn't need much carb work, just a normal adjustment. Set both the H and the L screws on the carb so they are one turn out from a lightly seated position. Refine from there.

Tom

stihltech · Nov 22, 2005

swap

Go with the last post. The Mag cylinder will require a machinest.

student1 · Nov 22, 2005

Hi Tom and Stihltech,
I appreciate your help very much. I'll try to get the saw running again based on your guidance. I'll post here again to let you know how I make out.

Cheers
Mike