I have a Saito 100 on my 90 size edge and if I am not mistaking it gets much hotter then the OS so I don't think we will have to worry to much about heat. At least I hope not.

Heres an example. One of the instructors has a custom built cap which is running the OS 1.20 FS I am running the Saito 100 as I mentioned above. His engine has no problem with the typical rubber extension you find in your LH attached to the end of his muffler. However that same type of rubber extension mounted to the end of my Saito 100 would not last 20 min in the air before it melted off. I have tried everything to keep it on even drilling a screw with RTV gold, no luck. The Saito is exiting inside the cawl which leaves a mess but nothing I can do. Weight is an issue so I can place anymore weight up front.

Although his engine is mounted sideways, his cawl was a scratch built wooden cawl that allows air to flow over the head.

I guess the only way to really find out is to give it a try.

Randy