An airplane collector/builder/flyer who has been out of flying more than 15 years brought me several planes and a box of engines asking for help to get back flying. ( SIG Kadet Seniors and a Telemaster 8ft wing) I read somewhere in the past about needing a shim if you are running higher nitro fuel. Is this correct? What fuel are you running in your Webra 61?
Two of these are the blackheads and one is a silver head. None have mufflers. These motors are in great shape! The only muffler I'm able to fing is the HB 300901.
I am just starting back into r/c myself...any help/suggestions will be greatly appreciated.

Thanks,

Sleepin