Hello Glyn,
my ST4 used a Litre of oil between services. I didn't think this was a problem.The one ting I did notice was that the harder I used it the more it used.When I was chasing keefyB it used more oil then normal.So have you been using the bike harder than normal.At about 14000 miles it stopped using oil at all, so it just goes to show Bikes are like Women unprodictable.
