I have an old but lively RF 900 which I garage in the winter.whilst running the engine which I do every month I noticed the oil in the engine was contaminated with coolant and the coolant was contaminated with oil.Having drained both systems down and leaving the sump plug out I connected a hose pipe to refill the radiator in the normal way and water gushed out the sump plug at roughly the same rate at which I was putting it in,so something seriously amiss somewhere! any ideas?