KX450 valves

[Troy Weeks]

So it's getting time to again check and probably adjust the valve clearance on my 2014 KX450. After approx. 5 or 6 races last season I checked them and they were in SPEC.
I understand the process
1. Measure clearance at TDC and determine if it is out of spec
2. Remove cam and valve shim buckets to get to shims
3. Measure shims and calculate shim needed to bring out of spec clearances to where it needs to be
So the question is this.
Should you set the clearance up to somewhere in the middle of the spec range or in either direction close to upper or lower measurement?

I guess this is based on whether the clearances tighten up or loosen up as all the parts wear!!

Looking at the service manual the intake clearance is suppose to be .10 to .15 mm.
They defined the "Mean Value" as .125 so it looks like they are using halfway between the range?
Ohh and I'm not sure I should take advise from members of my class. I'd hate to be SABOTAGED rof1

 

[Dan Aitken]

Troy, the valve clearance tightens as the seats and valves wear. If you want to service them more, set them to the middle of the spec. If you want to service them less, set them to the higher side on the spec.

 

[Greg Melka]

checking clearance is easy... adjusting is where it gets more involved, but certainly not a huge deal if you take your time. Most shim kits only com in .05mm intervals anyway, so you won't be able to get super picky about getting a clearance right in the middle. Ya might get lucky, or it may be just one side or the other of the middle range.

 

[ROBERT D'ANGELO]

I don't know why you can only buy shims in .05mm increments,but they come from the .factory in .01 increments.If you check them often you should adjust them on the tight side it will run stronger.You can ask the mechanic at the dealer if you can buy .01 increment shims that were taken out of stock engines so you can adjust them exactly where you want.If the valves tightened up by more than 1 size you should replace them, before it sinks in and starts chipping.My CRF 250 has gone 3 seasons without needing a valve adjustmentgoracing

 

[Troy Weeks]

I just looked at the parts diagram on the Kawasaki website and they only have the shims in .05 increments. I figured you wouldn't be able to get them right in the middle so I am trying to decide which side to set them to tight or loose.
I guess I will have to decide once it is determined which side puts me closer to the middle with the .05 intervals.

 

[Troy Weeks]

So I checked the valves yesterday and they are still in SPEC so I'm going to leave them alone.goracing