Valve's out of spec

[alkrisma]

all 4 were out of spec at 150 miles. is this the norm? what have you found with yours?

INLET (INLET Spec 0.004-0.006 in.)
R L: .178 mm (used 2.10) now .005"
R R: .178 mm (used 2.10) now .005"

Exhaust (EXHAUST 0.006-0.008 in.)
F L: .254 mm (used 2.10) now .006"
F R: .279 mm (used 2.00) now .007"

 

[HUSKYnXJnWI]

That does not sound normal from what I have read from guys like us...
My 09TE450 valves were in spec after 1300 miles- I avoid pavement and don't commute it. All "hard" dualsporting and enduro trail.

Your intakes were at .007" and .007" and your exhausts were .009" and .010"- right?, so they were all on the loose side- this would seem like the set them up loose- so this does not sound like wear- as wear ends up tightening the clearence...

Good on ya for checking them-

 

[Coffee]

all 4 were out of spec at 150 miles. is this the norm? what have you found with yours?

Mine were way off when I first checked my 2006 te250 at about 200 miles. I adjusted them and they have not moved at all since.

 

[rajobigguy]

It's not uncommon for the valves to need some adjustment the first time around because they need to seat in intially. If they continue to move then there is a issue.

 

[ghte]

Ditto mine needed adjusting on their first service and have stayed in spec since (now 4000kms).

 

[exit90a]

so this does not sound like wear- as wear ends up tightening the clearence...

I thought valves loosened with time due to shim wear? Seems like the shim would have to expand or the valve stretch for clearance to tighten. Maybe I'm wrong. My intake valves clearance loosened over time though. Exhaust have never moved.

 

[HUSKYnXJnWI]

Valve and Seats wear- so the valve works its way up into the head. the measured clearence then becomes smaller- If the shim wore exactly the same as the valves and seats- then you'd never have to adjust in theory. Shims wear but I don't think enough to matter.

 

[exit90a]

I wonder what made my intake valves loosen? Is it normal?

 

[rajobigguy]

I wonder what made my intake valves loosen? Is it normal?

Since it is the first time around it could be any number of things. They may not have been set properly to begin with, there might have been a high spot on the finger follower, a slight lip on the valve stem or even a burr on the shim. Whatever it is I wouldn't worry to much about it unless you keep getting loose readings everytime you check, that would indicate that valve stem and or finger follower is not the proper rockwell hardness and the material is compressing.

 

[exit90a]

It's not my first valve check. I've got 2300 miles and I think it's the fourth check. Both intake valves were in spec to begin with, .005 and .006 if I remember correctly. They have now both loosened to .007. I am waiting on a shim kit to come in. Am I correct in thinking I will need to use a size thicker shim to bring them back to spec since they are loose? Proper clearance for intake is .004 - .006 according to my manual. Thanks.

 

[nocontrol]

Yes, you will need the next size UP to fix that.

 

[Coffee]

Keep in mind, as I recall, the shims are 0.002" apart in sizing. So if you want the valves 'perfectly' in the middle of the range you can sand a larger thickness shim down... but personally I would not bother. I assume that is the reason for the 0.002 tolerance.

 

[exit90a]

Ok, checked the valves again this morning with the intention of adjusting them. Here is what I have- both intake .007 and one exhaust .009. This means each are .001 loose. Should I adjust them taking into account that they should tighten over time? Will they not fix themselves? The reason I ask is, if I do adjust it will bring them to the middle of spec, where they should be, but then as they wear I'll have to adjust again using the shims I will be replacing now. Is .001 loose cause for concern? Adjust or not, what say you? Thanks for putting up with my lack of knowledge and silly questions.

 

[alkrisma]

Ok, checked the valves again this morning with the intention of adjusting them. Here is what I have- both intake .007 and one exhaust .009. This means each are .001 loose. Should I adjust them taking into account that they should tighten over time? Will they not fix themselves? The reason I ask is, if I do adjust it will bring them to the middle of spec, where they should be, but then as they wear I'll have to adjust again using the shims I will be replacing now. Is .001 loose cause for concern? Adjust or not, what say you? Thanks for putting up with my lack of knowledge and silly questions.

I think you're ok.

 

[Slowpoke]

It seems odd that your getting those readings. First- I'd verify your readings with a different set of feeler gauges, just to make sure.
Also, how are you checking them? Are you checking between the follower and shim? (many guys have made the mistake of checking between the cam and follower, which can give incorrect readings)
If they are .001" loose, it won't harm anything mechanically. It just means your intake/exhaust valves will open slightly less than designed(.001"). .001 won't likely be enough to affect power output, but .010 would.
Valves tighten up over time, so being .001 loose just gives you a longer interval between having to adjust them.

 

[alkrisma]

question for all; when I put the feeler in (post adjustment) it has a snug/tight fit. that is better than loose, correct? my kit started with 2.10 and went up 2.35. I needed some shims a few sizes smaller but didn't have them

 

[exit90a]

It seems odd that your getting those readings. First- I'd verify your readings with a different set of feeler gauges, just to make sure.
Also, how are you checking them? Are you checking between the follower and shim? (many guys have made the mistake of checking between the cam and follower, which can give incorrect readings)

Why is it odd? Yes checking between follower and shim. I pulled the 3 shims, all were 2.25, so I need the next thicker size which would be??? I hope to find them at the Honda/Yamaha shop down the street, if not I'll have to order them. I know 9.48mm diameter, wondering about shim thickness, 2.30 or 2.35? Never mind on that, .002" = .05mm so I need 2.30.

 

[exit90a]

Honda shop had the shims, all done with each valve mid-spec. These bikes sure easy to work on.

 

[Slowpoke]

It seems odd in the sense that your valves are loosening up(according to your posts in this thread) over time and use.

The other possibility (as was pointed out earlier in the thread) is that there is abnormal wear happening on parts that shouldn't wear. ie. shims etc., or abnormal cam/follower wear.........
Something isn't right.......

 

[JasonfromMN]

I believe valves can also become looser(larger gap at the stem) if your light on the throttle due to carbon build-up between the valve and seat. Just a thought.