can anyone help please? i am working on my first renovation product a 1965 c15 and am nearly ready to give up. i have fitted new valve guides and have good compression ,i have changed the dizzy & coil and have a good spark at the plug . i believe the timing is correct as i have done it that many times but it still won.t start. all it does is backfire into the air filter. any ideas would help my other problem is actually kicking it over. with the plug out it is easy but with the plug in the kickstart seems to just slip without the engine turning. any help will be really appreciated,i thought this was going to be a nice retirement project but it has become a real windup.