55AX (OSMG0556)
Tech Note

Posted November 20, 2006

The 55AX does not come with a 90° adapter as originally planned due to significant power loss when using such an adapter.

If you look at the adapter that's available (OSMG2590) you'll notice that the exhaust opening in the transfer is much smaller than the exhaust port on the engine (55AX) and on the muffler. The restriction causes the power loss and if made to the size required would be too large and negate the reason for its use.

The OSMG2590 adapter can be used with the 46AX and 55AX but you will notice a significant drop in performance and the Power Box muffler in the "pitts" configuration will cause other engine mounting issues.