[amritc]

Hello, I just replaced the head on my CI Bullet 500 incl valves and guides. Also replaced the oil pumps  , oil pump shaft and the whole timing assembly which include the timing plate, CB point and auto advance assembly.
Upon start up the engine ticks over but I also hear a metallic clang that sounds like a spring compressing and opening on every single stroke... any ideas what this might be or should I tear down the head and timing chest again to investigate? Thank you all.

[ace.cafe]

First thing to check is the decompressor. If it is not assembled correctly,  it will do exactly as you described. If that isn't it,  then look under the valve covers.

[RE350]

Another possibility is valve spring coil bind. Had a Harley K model in the 1960s with same noise. Turned out someone put too many shims under the valve springs and the coils were collapsing into each other. Wrong springs or high lift cam a possibility.

[amritc]

Thank you. Will look into both and report back

[cyrusb]

My "clang" is made at idle by loose lifters in their bores, particularly the front (exhaust) one. Of course the frequency is not every stroke but every other stroke. Remove the lifter cover and wiggle the lifters, you may hear your clang.