Have a stuck piston via rusted rings, anyone know of a updated way to go about it without doing damage to the rod its alloy and the motor is a Sachs 80gs 1967 . thanks LG
The smoothest way to release it,(if you are not in a hurry), propably is to drain the whole engine into a barrel with diesel fuel. This cöuld take weeks but it should do the job :)
Mats from Sweden
I had the same problem with my 1968 Six Day; the piston rings were seized up in the cylinder. I tried knocking it loose with a wooden block and a mallet. I tried soaking it in kerosene. I tried heating the cylinder and coolong the piston. I was about to just take it to a machine shop to have it pressed or melted out. However, a friend told me to try muriatic acid to eat the piston out. It worked pretty good; just took awhile to get it done. And you have to be super careful not to let the acid get into the engine casing. It would eat a hole clean through it. Of course, this is only advisable if you're going to have to replace the piston and have the cylinder bored anyway. The acid will eat the aluminum, but will not harm the cylinder wall in the amount of time that it will be there. Make sure that you keep some baking soda close by to deactivate the acid. Make sure that you work in a well ventilated area.
Kimbal Lane Cox
CBET
LG,
You can use Evaporust. It will not harm the bore ( except for any rust it encounters). I have used it on cranks and the journals suffered no damage. Removed a ton or rust off a Wombat Iron barrel ( outside was a mess) and we went back with a Std piston just broke the glaze to seat the rings. Just need a plastic bucket big enough for the part and a lid. washes off with water then hit with CRC to displace moisture. I would buy it from the manufacture not off ebay or some place like that. It comes in gallon jugs
http://www.evaporust.com/
John D.
Thanks for the info, will go the organic way first via Evaporust then bring out the heavies if it does not work.