Valve clearance measurements

[reaction57]

Hello

I wanted to ask the majority of people doing valve clearance checks. I just checked mine on an 06 with 48,... miles. All my intakes were near the minimum spec. Around .16_.17mm. My question is would anyone adjust at these numbers? The exhaust were all in middle of spec. Any info is greatly appreciated.

Thanks

 

[RossKean]

Mine were near minimum spec on the first check. I left them alone and did not make any changes until 100,000 miles.

Button it up and wait for the next time.

Edit to clarify: Valves were checked at regular intervals (although less frequent than recommended) but none of the shims needed changing (clearance below minimum spec) until the 100,000 mile mark. I set them all to about two thirds of the max clearance specified. Exhaust valves (at least to 175,000 miles) have never needed adjustment.

 

[Harald]

Like RossKean, my 07 was close to the limits for a couple checks. In limits is in limits, so no reshimming needed unless you feel like doing extra work.

I don't remember exactly without looking at my logbook but around 100,000 miles (might have been 120,000 miles) I had a couple too tight, so I adjusted all to mid range in hopes of never having to do another adjustment.

 

[MCRIDER007]

Mine were near minimum spec on the first check. I left them alone and did not make any changes until 100,000 miles.Button it up and wait for the next time.

What he said....

 

[rtesta65]

My friend works as the Quality Assurance manager for an aviation company. We were talking about wear limits and manufacturer's specs. He said if it is within spec then it is in spec and does not need to be changed.

He is a brilliant guy so I trust him. Besides -- if he were wrong about these things, in his field, people could die.

 

[reaction57]

Thanks for the input. Didn't know how critical the intake spec was. If it were the exhaust I think I would adjust. Now to do the tensioner update and put it all back together.

 

[Mr. BR]

I would agree as well.... leave them alone. If it were the exhausts right at the limit, I'd be a little more inclined to give them a small nudge towards the middle of the range.

Which reminds me... I checked mine at 48K (upon purchase) and adjusted only two: 1 exh and 1 intake. Now, 20K miles later I wonder if I should check them again... I hear ticking once in a while... valve or injectors?

Na.... I'll leave them for now.

Mr. BR

'05 FJR

 

[Fontanaman]

I will go against the grain here. I prefer to have them .001 over minimum cause over time they will only get tighter. If you got it all apart it is really not much trouble to assure they don't get tight over the next 25 k miles.

 

[eflyguy]

Pretty sure the manufacturer would have taken that into account when specifying the service interval..

 

[RossKean]

Pretty sure the manufacturer would have taken that into account when specifying the service interval..

Agreed. The minimum specification would be set so that, with normal wear, the amount that it might end out below the minimum spec would still be safe by the time you get to the next service interval. The minimum specification is not the minimum tolerance before you run into damage due to a burnt exhaust valve or compression loss due to intake not closing fully. The safety margin is such that it should still be "safe" until the next scheduled time. If, however, you are removing the cam to change any of them, it makes a lot of sense to move them all to the wide side of middle of the range. Good chance you will never have to make another adjustment.

 

[reaction57]

Pretty sure the manufacturer would have taken that into account when specifying the service interval..

Agreed. The minimum specification would be set so that, with normal wear, the amount that it might end out below the minimum spec would still be safe by the time you get to the next service interval. The minimum specification is not the minimum tolerance before you run into damage to a burnt exhaust valve or compression loss due to intake not closing fully. The safety margin is such that it should still be "safe" until the next scheduled time. If, however, you are removing the cam to change any of them, it makes a lot of sense to move them all to the wide side of middle of the range. Good chance you will never have to make another adjustment.

This is great news to have!Thanks again

 

[Fontanaman]

Pretty sure the manufacturer would have taken that into account when specifying the service interval..

I suspect so but it is my motorcycle but I'd rather not experience a tight valve.

 

[MCRIDER007]

Pretty sure the manufacturer would have taken that into account when specifying the service interval..

I suspect so but it is my motorcycle but I'd rather not experience a tight valve.

if you were to experience a tight valve you probably would not know it until you did your next valve check.

Everyone worries about a tight valve resulting in a burned valve but the valve clearance would have to be zero when hot to burn a valve and as long as the cold clearance is .002-.003" there is little chance of that happening...especially on an engine that is fully broken in.

 

[eflyguy]

(and, again, recommended service intervals assume that the average owner isn't laying awake at night wondering whether the valve stems have worn beyond tolerances in the two years/1000 miles since the last check!)

 

[reaction57]

I am doing the cam tensioner update also. I just got my parts and it doesn't have the blue dot! Its green. Is this still the updated tensioner?

 

[RossKean]

I am doing the cam tensioner update also. I just got my parts and it doesn't have the blue dot! Its green. Is this still the updated tensioner?

Yes

 

[BanjoBoy]

Pretty sure the manufacturer would have taken that into account when specifying the service interval..

I suspect so but it is my motorcycle but I'd rather not experience a tight valve.

if you were to experience a tight valve you probably would not know it until you did your next valve check.

Everyone worries about a tight valve resulting in a burned valve but the valve clearance would have to be zero when hot to burn a valve and as long as the cold clearance is .002-.003" there is little chance of that happening...especially on an engine that is fully broken in.

Purdie much ^THIS^ In all the years read'in posts, on this here forum, I don't recall anybody have'in burnt valves.

Anybody?

 

[Fred W]

MCRIDER nailed it. The minimum clearance spec is chosen by the manufacturer already considering the possible rate of further wear between checks, and then allowing a healthy margin of error on top of that. Consider also that the clearances are measured with the engine at room temperature. Actual clearance at running temps can’t be accurately measured, but those same engineers know how much that change will be too. If the clearances measure anywhere in the spec range, even right at the limit, they are good for at least another 26k miles.