I've owned two ZDZ engines, a 60cc and now a Super 80, and I have always set the timing to the manufactures recomendation. The settings have always worked just fine, but I have always used a Pitts muffler and a two blade propeller. The thought of changing the timing was not even considered then, but I recently changed to a canister muffler and a 3 blade propeller, and I'm experiencing some mid-range issues. ie the reason for considering the timing change a an experiement prior to making any changes to the header.. ie my posted question to mike.

I got a reply from Mike at RCS

Patrick,

With the TR-80, you MUST use the wraparound header at its full length. DO NOT SHORTEN IT.

We use this setup with the 26x12 2 blade and get 6400rpm.

The 24x12 should be close.

The silencer must be getting cooled sufficiently to work properly as well.

Please look at tell me what carb is installed on the engine.

I hope it is a Walbro WJ71.

Let me know.

Thanks,



Mike Dooley