valve lash

[pampadori]

i have a 72 cb750 with a yoshimura cam.  the climer book says adjust lash to .002\" on the intake and .003\" on the exhaust.  the yoshimura tag recommended .006\" for all valves.  motor is ticky as hell.  so i set them to .002 and .003.  what do you guys run on clearances?

[SteveD CB500K0]

I have never run any of my SOHC Hondas on anything but the factory settings of 2 thou intake and 3 thou exhaust.

But then I've never had a hot cam either.  There must be a reason that Yoshi recommend wider gaps?

[pampadori]

well i rode the bike again yesterday.  its still awfully loud.  are these motors naturally noisey? i adjust the timing chain while i was doing the valves.  maybe i didn't get that part right, i'll try doing it again and see if it gets a little quieter.  or maybe its the forged pistons i'm hearing.  runs good, but the noise is geting old.

[JonnyB]

As Steve says, as per the manual, but if you have a yoshie, with different lift, you would be bet to do as they advise.

My F1 is very noisy, and I suspect camchain it's that sort a rattle, check your tension, it seems I have to do mine every week.

[lordmoonpie]

Yup you better use the Yoshi lash values for settnig as the longer lift and duration will mean lots of valve train stress on standard settings which could lead to failure somewhere in the system eventually. My megacycle race cam is set at 5 thou inlet and exhaust - it's fairly standard to increase the clearances for hairy cam lobes!

[Asimohonda]

I run a Yoshimura Camshaft in my CB750 F1 along with RC Engineering valves & springs.The settings I run at are 006 thou on all valves as per Yoshimura,s advice Don,t run the bike on standard Honda cam settings Always use the Yoshi cam settings,the noise you discribe & complain of sounds like cam chain rattle not valve noise check that first!regards Asimo