[b]DSK:

See I missed part of your question. Radial mounting, directly to the firewall, would eliminate the weight of a separate mount. If you don't have to run your fuel lines through the center of the firewall, this mounting is practical.

A plastic composite mount does give some vibration isolation, but these little engines are smooth enough I don't think there would be any problem with the radial mount other than hose routing.

Just be sure to balance your props, and spinner if used.

Bill.

PS: Use a fuel with a castor/synthetic blend lube. They do not like all synthetic. wr.