YZF 250 F valve clearance

Anyone help me understand what could be the cause of not being able to get the right measurements of the valve adjustment? The manual states exhaust 0.17-0.22mm and I’m only getting at most a 0.008 mm feeler in there. On the intake it’s supposed to be 0.10-0.15 mm and I’ll be damned if I can’t get a .003 gauge in it. Let’s assume I’m not stupid and do know about mechanics and I do have the piston is at TDC. Thanks in advance!
 

SRAD97750

Moderator
Staff member
Howdy,
That's the valve wear you're checking for specifically. They need to be adjusted back into spec.
If they can't be adjusted into spec with available shims, the head needs a complete valve job.
-BIG DAN:thumb:
 
Howdy,
That's the valve wear you're checking for specifically. They need to be adjusted back into spec.
If they can't be adjusted into spec with available shims, the head needs a complete valve job.
-BIG DAN:thumb:
BD, so that’s the norm? I was thinking I could fit an airliner in there if they were worn out?? Not the opposite. Thanks brother!
 
What year?
Have you shimmed since you’ve owned it?
If
You have to go more than .10mm it probably could use a head job or valves at the very least.
 
What year?
Have you shimmed since you’ve owned it?
If
You have to go more than .10mm it probably could use a head job or valves at the very least.
2001 and I bought it last year for my son so I’m not sure what’s been done.
 
I’d call that zero’d out. Those heads are pretty reliable, but being so old I’ll pull it and rebuild it, or at very least inspect the valves and seats.
 
Let’s assume I’m not stupid and do know about mechanics. I’m only getting at most a 0.008 mm feeler in there
If you know about mechanics, you know details matter. I’m fairly certain You do not have a .008 mm feeler gauge. Get a manual, Tear that motor down to the crank and rebuild it. If if runs when you’re done, you will have learned more than you ever thought you knew. Not to mention, it’s FUN! Good luck!
 
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