Hey guys i would like to know if looser valves cause a leaner mixture. Does anyone know how it changes the air fuel mixture?

 

I could see looser (valve lash) intake valves causing a little less air to come into the CC, but how much less air to be considered lean or rich is questionable...
Im thinking looser valve lash is going to decrease valve lift AND duration, thus causing LESS air to come in, resulting in a rich condition...
This is all just a guess though...

 

Valve lash does not have any effect on fuel mixture. The mixture ratio has already been determined before it passes through the valves.

 

Don't loosen your valve lash! Buy a fuel pressure regulator. B&M makes one for like $75 shipped new. Or you can probably find one in the "for sale" thread.

 

noo im not loosening my valves for fun. i just blew my motor twice within a week same pistons 3 and 4. my cause was tight valves. now i have the car running again and i see that my mixture went a little leaner on idle. i have to redo the valves but i was just asking if it changes the mixture.