• The Biplane Forum is a large global active community of biplane builders, owners and pilots. From Pitts to Skybolts, to older barnstormers, all types are welcome. In addition to our active community, our content boasts exhaustive technical information which is often sought after for projects and maintenance. This information has accumulated over the 12+ years the forum has been in existence.

    The Biplane Forum is a private community. Subscriptions are only $29.95/year to gain access to this great community and unmatched source of information not found anywhere else on the web. We are also a great resource for non biplane users, since many GA aircraft are built the same way (fabric and tube construction).

WTB O-540 B4B5


Oct 13, 2017
Reaction score
On the off chance someone has an O-540 B4B5 sitting around waiting to overhaul it, (run out is fine I am looking for the crankcase and accessory plate) I would be interested in purchasing it.

If you have a working O-540, I would be interested in it as well.

You can pm me or you can email me at
Loogief16 at yahoo dot com


Latest posts