I'm putting together my first kit and I'm running into some trouble with the Spinner Backplate hitting the Cowl. What's the best way to bring the spinner out a 1/4 inch of so without having to move the engine. I'm hesistant to move the engine because there is already very little of the cowl left to fit around it in the front. I had to move the engine all the way back on the mounts to get it to fit already. Would a large washer of some type work??

You can use a "Hole Saw" and cut a disk of aircraft plywood to use as the spacer. You may need to glue some 120 grit sandpaper to the face of the disk which will be next to the propeller to prevent slippage.

As long as the disk is cut from aircraft ply... there should be no problems with it not having parallel faces. If the added thickness does not prevent the propeller and spinner backplate and washer and nut from gong on correctly... it will work fine. (You MUST have 2 complete threads showing outside the nut... or if using a spinner-nut by dubro, you need at least 7 turns of thread engagement.)

If you are using a plastic spinner such as a DuBro, the back plate is recessed and actually robs you of clearance. Switching to an good aluminum spinner, such as a Tru Turn, will give you the clearance you need. The aluminum back plates are usually flat.

The distance from the thrust washer to the engine bulkhead is always the the important measurement. Why can you not just slide the cowling in closer to the engine bulkhead. Are you trying not to cut the cowling for the engine? What airplane/engine are we talking about? Got any pics?

I've have cut the Cowl for the engine. I just ran out of cowl to cut out. If I slide the engine up anymore I'm going to have to cut that last 1/4 inch of the front flange out completely. The model is a Kadet MK11 and with a Thunder Tiger .48 engine. I might try the Aluminum spinner if I can find one locally.

There are several plastic spinners with flat backplates too. Great Planes is one.

YOu can put a spacer behind the engine mount to move the engine out.

Then he would have to cut the cowling and would not leave any of it left around the front of the nose