I have a Thunder Tiger GP-61 and was looking for a pitts style muffler for it. My question is, will the pitts puffler for the OS61FX fit it? Has anyone ever tried a different brand of pitts muffler on this motor?

The os61fx pitts muffler fits the tt61pro - does the tt61gp use the same tt muffler as the pro?

Good question, anyone got an answer?

It'll fit. I have a TT .61GP and an OS .61. The mufflers interchange.

Thanks Ed. That's the ticket!