TinTop,
I am contemplating further modifications to the frame on my 550 - a bad habit I have when it snows too much, leaving me with far too much spare time - and I'd like to ask you for a measurement off your bike. Specifically, in this picture:
Looking that the forward vertical frame tube, the one that accepts the rear motor mount bolts, can you tell me the distance from some fixed point, say the top of the upper motor mount bolt, to where it would intersect with the bottom and top of your air filter mount? In other words, I'm thinking about welding another tube onto that tube somewhere in that area, and I don't want it right in front of the filter system, once it finds it way to the bike. Actually I'd like to locate my tube to intersect that down-tube somewhere very close to, possibly just above, your airfilter system.