78 kz1000

my 78 kz 1000 has a ticking sound coming from left side of engine, happens only at a idle, i can put my head against the tank and it sounds brutal, any ideas, plenty of power and i have been running it this way for at least a year, i recently rpace valve cover gasket and everything in there looked good, even checked for the timing chain to be loose, but couldnt find anything, any way to test this to see where or why or should i worry?
thanks,
Ben

Might be sound of spark arc through leaking insulation on old deteriorated plug wires.

Or possibly excessive valve clearance -- checking gaps is a routine maintenance item.

Maybe a leak at the exhaust header where it attaches to the cylinder head. Any evidence of seepage around the area?

Supposing a blown or leaking head gasket might also be a possibility (evidence of leakage should be visible). Would assure cylinder head bolts are torqued to specs.

Good Luck!

If you have a vacuum petcock and the sound is really loud when you put your ear to the tank, it's probably the petcock, rebuild for $50 and hope the sound goes away or replace with a suzuki petcock or get a manual petcock. And just to be sure it's not arcing from the coils to the tank put a piece of rubber between the coils and the tank. However I highly doubt it's arcing because which ever plug wire is arcing it will also not fire that cylinder and you said the bike is running fine. I've actually had BOTH problems arcing and ticking petcock on my '78 1000.

The arcing problem is what I would suspect.

check to make sure the valves are properly adjusted.