A and A25 cylinders are not interchangeable.A25,A35 and A45 are same but,A model is very different.I have fixed cracks exactly like those using automotive “stop leak”.First I put some carb cleaner/degreaser in the cylinder water jacket then used low air pressure to force cleaner through crack to clean it.Then I used water and finally stop leak using same process.Took two applications of stop leak allowing it to set up each time.Worked great both times I’ve done it.
