Question: How do valves tighten over time?

[dazzler24]

17 hours ago, knyte said:

So it seems like 32k km / 20k mile intervals would be roughly the sweet spot, maybe a bit more.  35k kms / 22k miles or so.

That's what I've gleaned from all this knyte.  I checked mine early for peace of mind at only 20K kms/12K miles and all were in spec.

I've made a note in my service records to check again at 33K kms so that puts it roughly in the middle of your estimations too.

I do prefer to err on the side of caution and the peace of mind factor for me is important so, happy to check early.  Looks like these checks can be safely stretched a bit further apart beyond the first two or three after everything  has bedded and settled it would seem - based on the experts opinions here.

[knyte]

15 hours ago, dazzler24 said:

Looks like these checks can be safely stretched a bit further apart beyond the first two or three after everything  has bedded and settled

Yeah, great point.  I wonder if it has something to do with varying metallurgy between factory shims & different production runs vs aftermarket shims or something.
 

[RaYzerman]

It won't be the shims, they wear extremely little.  Same with cam lobes and buckets.  It will be the heads of the valves cupping mostly and they may be titanium (as opposed to titanium coated).  In any case, sounds like best check that first time early, and then a regular interval to see how it's going.

If you've done a lot of valve checks, seems at least Yammy and Kawi shoot for nominal at best at the factory, and never really go over that.

[piotrek]

On 12/4/2022 at 1:24 AM, knyte said:

So it seems like 32k km / 20k mile intervals would be roughly the sweet spot, maybe a bit more.  35k kms / 22k miles or so.

I did mine at 37K km and two valves with tightest lash (.114 and .165) already rode the heel, enough to show marks. I'd say that was a bit late. Checked twice since, and all remains good at 82K. YMMV of course.

Edited December 6, 2022 by piotrek

[piotrek]

21 hours ago, jay547 said:

I had my first at 45k miles. Exhaust valves were tight. The tech said that I nearly waited too long. He said to bring it back at 70k.

Did the tech give you the before and after measurements?

[Brentinpdx]

Seriously though.. The best advise is to check your valves before or at the specific interval. Not after. Just because many replies on this thread have gone longer and still in spec. Doesn't  mean yours will. Intakes wear less as they are cooled by incoming fuel and air. Exhausts get hot and wear due to seat recession. Once they are tight, they will begin to stretch. Because of the lack of lash between the valve stem and the shim/ bucket and cam lobe. They stretch because they are slamming shut. This accelerates the seat wear and they will eventually  burn. The other side is that they can stretch and break. At that point your day is done. Your valves should make some noise. If it is quiet , they are probably getting tight.

[helene]

Dear all,
I get some very concerning readings of the exhaust side valve lash at 24k. Just to confirm, the exhaust valves on a cylinder, check at the same crank position as the intake? By inference, this should be correct because there is no overlap between opening in this triple... is it?

If I read my exhaust lash correctly, and I have not yet experienced a chordal failure (because the reading I get would indicate massive beat-in), I can only infer that the specifications are incorrect in the manual?
Kind of like their crackpot specified drive chain slack?
Did the factory set the valve lashes to the same spec all around initially, and the lash is in fact rather stable?

All my stator-side exhaust valve lashes are at .003". The clutch-sides are .006". Specified minimum is .010"!! In all likelihood it is me not measuring correctly... I'll go back and triple-check... Any input welcome.

[skipperT]

-Check it with the exhaust cam lobes  “in-line” with the valve. (Or facing away from). Follow the book to set cyl #1 at TDC. Remember there are 2 marks on the rotor!!! One for measurement, the other is for cam R&R (the K mark).

-AFAIK no one has EVER pulled a valve cover on a new bike on this website to confirm that Yamaha sets the valve clearances one way or the other. I personally call BS on anyone who says they were “set wrong from the factory”.  Really? Prove it to me then… AFAIC that theory has no basis in reality. Valve clearances change, on some motors more than others. The CP3 seems to fall in the more-camp. 

-specs in the manual are correct. Don’t F with them. That said I’ve gotten away with setting the Ex to a tight 0.33mm but YMMV. Shoot for 0.27-.30mm Ex. 

-and no, don’t worry. Your clearances are not unexpected for a CP3. Loosen them up and be glad you checked them. You may want to make sure you have a shim selection +or - whatever number you calculate (probably between 1.62-1.78) in case you need to make a second adjustment. 

-I recommend inserting the feeler gauge from in between the cams and moving toward the forward/exhaust side of the engine. You can see the tappets more easily and get a better feel from that angle. 

-Skip

[bwringer]

Make DAMN sure you are working in hundredeths of mm and not thousandths of inches. Much wailing, and gnashing of teeth has resulted from unit confusion.

[2and3cylinders]

Skip

Next check I'll have to note which direction I insert the feeler gauge.

Like aiming aiming for a small target you can't hit what you can't see

As I've gotten older, maximum illumination during this type of work and thinking the process through in a relaxed manner is the way.

[OZVFR]

On 6/24/2023 at 12:49 AM, 2and3cylinders said:

Skip

Next check I'll have to note which direction I insert the feeler gauge.

Like aiming aiming for a small target you can't hit what you can't see

As I've gotten older, maximum illumination during this type of work and thinking the process through in a relaxed manner is the way.

This is the way. (I hope some of you have watched The Mandalorian)

I have two sets of feeler gauges (imperial and metric) that I bent to allow easier access, made life a lot easier on my old VFR and Sprint.

 

[2and3cylinders]

5 hours ago, OZVFR said:

This is the way. (I hope some of you have watched The Mandalorian)

I have two sets of feeler gauges (imperial and metric) that I bent to allow easier access, made life a lot easier on my old VFR and Sprint.

 

Oz

Did you catch the last 3 words of my last post?

I'm dieing for the next season to start!

I'm very depressed Ted Lasso and the Marvelous Mrs Maisel ended.

Waiting for Extraordinary Attorney Woo and Slow Horses too

[bwringer]

On 6/24/2023 at 7:29 PM, OZVFR said:

I have two sets of feeler gauges (imperial and metric) that I bent to allow easier access, made life a lot easier on my old VFR and Sprint.

Yep -- stop trying to use Grandpa's janky old feelers marked in barleycorns or cubits, and order up a set of metric feelers. They make life much MUCH easier. I don't know if bending them is 100% necessary on this bike, but you can do that or try a pre-bent set.

I'd also highly recommend scaring up a digital micrometer that reads directly in mm for measuring and verifying shims. Harbor Freight sells an excellent example for $45 that works just fine for this purpose.

Work in mm all the way through, and you'll avoid a whole raft of errors.

Edited June 26, 2023 by bwringer

[OZVFR]

On 6/25/2023 at 3:00 PM, 2and3cylinders said:

Oz

Did you catch the last 3 words of my last post?

I'm dieing for the next season to start!

I'm very depressed Ted Lasso and the Marvelous Mrs Maisel ended.

Waiting for Extraordinary Attorney Woo and Slow Horses too

Have you watched Cowboy Beebop? 2&3?

Sorry for the high-jack.