tick over and back firing problem

Hi Guys
After rebuilding our ST70 engine it was burning a slight bit of oil so I dicided to give the bore a light hone to remove any glaze when I started it back up it was not burning oil but I have a small problem , When I am kicking it over it back fires through the carb but does start but will not tick over it also runs on when you shut the throttle off , I rechecked the cam timing and with the `T` lined up the `O` mark on the cam shaft will not not line up with the `0` mark on the cam cover (left side of the cover hole) it looks like its 1/2 or 1 tooth out .I dont remember this being like this before ??

Half a tooth above or below the mark is normal on most engines.
Did you fit all new gaskets?
Sounds like an issue with the head gasket. Make sure you carefully clean all surfaces before reassambling the top end.

Also, check valves for play, leakage and disribution and ignition:
Worn chain, sprockets, correct tension,...

All info on what you exactly did on the engine whould be helpful.
For example: after honing the cylinder you should fit new piston rings.

Waynus wrote:Half a tooth above or below the mark is normal on most engines.
Did you fit all new gaskets?
Sounds like an issue with the head gasket. Make sure you carefully clean all surfaces before reassambling the top end.

Also, check valves for play, leakage and disribution and ignition:
Worn chain, sprockets, correct tension,...

All info on what you exactly did on the engine whould be helpful.
For example: after honing the cylinder you should fit new piston rings.

Wayus
I fitted a new piston and rings and cleaned all the surfaces and fitted all new gaskets and seals , It was only burning a slight bit of oil before and would start seconed kick with no back kick it would also tick over really nice .The cam chain is very tight and I have said this in a older thread . Its not burning oil now

Is it a manual or auto cam chain spanner?
Are you sure the cam chain runs correctly over the rubber sprocket? (Left side of cylinder)

I'd check the carb / manifold for air leaks (spray some deodorant over the manifold / gaskets while running. If you notice a change in revs, there is an air leak)
Also, check if the fuel is running smooth, renew spark plug, check valve play and leakage, reset ignition timing.