Well, I took it to Mallory on Friday having spent most of Thursday fettling. I made up a booster battery pack and fitted a new spark plug . I discovered that the ferrule on top of the spark plug was missing so it wasn't making good contact with the cap. that explained a few issues with starting and running. It now starts much easier. At Mallory all was good. It started well and ran well. Got through noise test at 92db with a baffle. Did the first session and it went really well, it stopped well handled ok and pulled well. However when I pulled in, a puddle of oil formed underneath which was from the rear shock. I pumped the rest out and tied some cloth round it to soak any up. I then decided to to add some fuel to the tank. I think the inside of the upper portion of the tank was coated in Dust/mould / crap I don't know what, but adding fuel loosened it all up and turned it into pond water. Since then it wouldn't run for more than half a lap before stopping. 30 seconds late