To / 1200rallycar,
By all means. If you happen to come across a decent one drop us an email and i could organise something with you. I should be able to organise the necessary adapter plate down here somewhere or even through mail order.
To/ ddgonzal,
Actually you raise a good point there that I may have over looked "the mechanical advance".
I take it what you are saying is that evrything runs fines maybe a couple of times or so under heavy acceleration but sometimes is not releasing from the advance position after I back off the throttle?
In theory this would make sense as to what happened the other day. As after a minute or so and a some light throttle applications it probably free'ed up and returned to its position thus the pinging stopped.
I did check this with the dizzy cap off in the usual manner turning rotor and ensuring it springs back ok but maybe it is sticking out on the road if driven hard.
The more i think about this i reckon i'm chasing two different problems
1) Vaccuum leak at manifold & throttle shafts causing the weird idle.
2) Possible the advance mechanism or something causing this pinging problem.
If 1200rallycar could source a good carb then i would go that way to start with as i dont really fancy spending any money doing the Hitachi.
Anyway I can prove this is the mech advance other than a dizzy rebuild?
Thanks.