Stihl 038 AV to Magnum

[a. palmer jr.]

I have a Stihl 038 that a customer wants rebuilt, at least a new top end. I looked over the offerings and for the money I can built a 52mm engine cheaper than the original 50mm one. I know this has been discussed before but I'm having trouble finding the thread. I know the holes on the 52mm cylinder will have to be elongated to fit the narrower 50mm engine but is there anything else I need to do? Thanks

 

[Wood Doctor]

I have a Stihl 038 that a customer wants rebuilt, at least a new top end. I looked over the offerings and for the money I can built a 52mm engine cheaper than the original 50mm one. I know this has been discussed before but I'm having trouble finding the thread. I know the holes on the 52mm cylinder will have to be elongated to fit the narrower 50mm engine but is there anything else I need to do? Thanks

Seems odd that you have to rebuild that much. Did you check the 52mm kits on E-bay out that run about $30? Usually you do.

 

[Mad Professor]

Seems odd that you have to rebuild that much. Did you check the 52mm kits on E-bay out that run about $30? Usually you do.

52mm cylinders have a different bolt pattern, the 50mm and 48mm cylinders are a bolt on switch. And besides, a $30 kit is going to be made of high grade Chinesium.

I used a NOS OEM Stihl 52mm Mahle P/C kit on the conversion I did in 2008. That saw still runs great. Some links below.

038S to 038M

038S to 038M (another thread)

Others here have done the conversion too. One variation is you can turn down the cyl bolt heads a bit so you don't have to grind the cylinder near where the bolts seat.

Mastermind did the conversion and hot rodded the saw a bit.

 

[a. palmer jr.]

Seems odd that you have to rebuild that much. Did you check the 52mm kits on E-bay out that run about $30? Usually you do.

Yes, I checked them out and all I found were the 52mm kits other than those 50mm ones that were over $100 and they were Chinese too. Most of the guys around here don't want to pay what OE stuff costs. I assumed the 52mm kits were not bolt on unless your saw was already a Magnum. I measured the piston on the one I'm working on...50mm.