assuming it does turn out to be the splines... you can make a stand made of 2x4s and 4x4s. mine was two side support beams along the ground with a 4x4 crossbeam whose top was a smidge higher than the sump bottom. i plopped the bike onto it from the centerstand (sitting on the beam just behind the oil filter), then used ratchet ties to strap down the heads onto the side support parts of the stand. it ended up sitting for a few months split in half without problems
also interested in total mileage on ze bike
