upon cold startup, my nc30 is on the button and the engine purrs. when ive had it out for a good rake and it gets well warmed up and the oil thinned a bit, it develops a light ticking noise at idle. almost like valve clearance are too big. I set them bang on spec when i rebuilt the heads so am 100% sure thats not the issue. The bike is running like a champ and this 'noise' im hearing is not affecting anything other than my head . It sounds like its coming from the carb area, not the heads themselves. Any ideas?

Mine have always been tappety when they're nice and warmed after a run.

If the sound isn't an exhaust leak of some sort I wouldn't be too concerned, this noise is normal on a hot nc30.

You'll soon see that it's directly related to engine temperature (not necessarily water temp!), and just part of the bikes character.

what he said, these bikes are getting on now and if you are happy with the valve clearances, then there is nout to worry about. just one of those things about the V4

thanks lads thats what i was thinking. Jus a characteristic of the engine. TBH ive never heard another vfr400 running before to make comparison. Like i said its running great so il not be delving any deeper to try and find a problem that doesnt exist.

as said its' probably just wear in the valve gear / characteristic engine noises.

Have you checked the valve clearances / know when they were last done?

Once there set up fine any other ticking noise shouldn't be anything major :)

ive only done 100 odd miles since i rebuilt the heads. And i set the clearances were almost perfect.

I had exactly the same noise on mine till i rebuilt the engine. With the valve gear train re-installed with a slightly different fit, the noise disappeared. Its almost certainly in the gears driven off the crank, or the cam gear.. Its generally regarded as not a serious a problem, but the ticking got louder on mine over time.. If this happens on yours taking the head where the noise seems to eminate from and re-seating all gearing might solve the problem, tho the hassle of doing this would only warrant a serious noise i suspect!

Mine does the same thing, as said I just put it down to age and how these bikes are invariably thrashed about!