Ok so i have tried 180 degrees the other way on the timing and still compression appears to be venting from the exhaust.
I stripped her back to the piston which seemed good and have checked the valve adjustments. The amount of times ive reattached the cam followers beggars belief.
I'm still stumped. I still have a spark (so I'm assuming - I know mother of all mistakes -but still spark should mean CDI and stator are ok).
Could a valve have bent from such a short run?
I have a compression tester, but really helpfully it doesnt work (I know this because it wasnt working just before I started her up).
The other mysterious thing is when testing fueling, I covered the back of the carb air intake, and ended up with fuel on my fingers?!
It feels like there is suction but also air blowing back on itself.
If anyone could suggest anything else to consider I would greatly appreciate it
(Piston, piston rings and cylinder seemed ok. Sprayed oil inside the cylinder to check it couldnt pass the piston which it couldnt. Are the valves the only thing remaining that are a possibility or have I missed something really obvious?
Thanks for any help
JB