ORIGINAL: hogflyer
What is the need for a .91 in a Kadet? What structural reinforcements have you made to take this much power – to the firewall, fuselage, wings, empennage???
You should have at least 1” of brass tubing sticking out of the fuel tank for the fuel lines to slide on. You need to extent the tubing and bend it (use a tubing bender so it doesn’t kink) so it runs up behind the engine, and inside the firewall. If there is not enough tubing to do this, then get some more brass tubing and make new lines.
Guys who fly Kadet Sr.’s on floats or glider tow use .61's, and that is all the power it should need. If you want to do 3D, then get a Twist 60, Showtime or Funtana to put your .91 on. Kadet's fly well on a .46 AX, and will even fly with an OS .40 FP or LA.
If this was my plane, I’d pull the .91 and install a .61 with new motor mounts. This way the engine should fit the cowl. If you are intent on using a .91, then you may want to consider building up a wood cowl like the Kadet Sr. kit utilizes.
Hogflyer
come on........you guys dont know how to use your left hands????... throttle management...just so you guys know a 91 size engine is the same size case as a 61 basically the same weight as well just that extra power. Last time i checked he is not a complete newB so stop bashing him on his engine choice and help him out with his problem. Back on topic. IMO that brass tube length is OK. i have had a few planes at that length and never had a problem with them. What i did do though was put mini tie wraps on them and seemed to work great.