Valve Clearances in spec, but can they be MORE in spec?

On the intake side I've got one valve thats way too tight (like a .06) so I definitely need to change the shim on that one. But the other 3 valves on the intake side are just barely in spec (right at .11)

.11 is on the tight side, right? So, while I'm in here can I change the shims so its closer to the .15 end of the spectrum? I know they tighten over time, so since this is my first valve job (and hopefully last for a while), I would like to set everything towards the "looser" side of the clearance.

I haven't looked too much into the shim sizes yet (I still have to get em' out and see whats in there first), but is this possible?

 

Since the shims come in .05 increments you'd have to take your .11 intakes (in spec.) to .16 (out of spec.).

 

hmm... ok. that makes a lot of sense.
Now here's another question.

Do I just fix the one valve then? wait a couple thousand miles for the other three to "tighten up" and then reshim them so they're in spec.

Or can I set it to an out of spec .16 and ride it like that for a little. What is the effect of that? I just don't want to run anything tight or burn up a valve.

 

You just do the one.

In spec is in spec. You don't adjust out of spec hoping it'll wear in.

They tighten up as the valves and seats "wear in" to each other. After thet break in period they tighten up very slowly.

This past winter I did the first valve lash on an 04 Venture with 47K miles on it. Fifteen of the sixteen valves were still in spec, one was just a hair tight. Clearly Yamaha is machining a good enough match they don't break in very much.

On the other hand, I routinely see Chinese scooters with less than 2K miles on them where the valves are so tight the engines quit running when they warm up. Clearly they aren't produced to the same tolerances Yamaha pulls off.

 

Alright. Thats what I needed to know. Thank you very much, sir.

 

i would of just put it to 16 it wont be a proublem,i did the same,you mite here the valves a little more,but i would rather here them then not here them

 

No, Carl is right. In spec is in spec; out of spec the "other direction" is still out of spec. Once they "settle down" they don't change very quickly.

Put them IN SPEC and check every 5K miles as recommended. Best practice for the long-term health of your old mill.