H9 330L firewall
 

should there be a hole in the firewall for the spring start on the GT80
does it just bolt up with room

firewall hole
 

Yes the firewall needs a hole for the spring starter. Be sure to make a box to seal the back side of the hole to keep the fuselage clean.

I converted my GT-80 to C&H syncrospark electronic ignition and eliminated the spring starter and saved 1/2 pound. The spring starter is heavy and needs some maintenance from time to time.

Bruce