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12k, err 13,500 mile valve check

2164 Views 15 Replies 10 Participants Last post by  black-bonnie
I just checked my valve lash at dang near 14,000 miles, here are the results:

Intake spec should be: .15mm-.20mm

I observed:

.229 .229 .203 .178

Exhaust should be: .25mm- .30mm

I observed:

.305 .330 .330 .330

I'm going to leave them alone. From what I understand a little loose is better than a little tight. They are within a few 100ths of a mm, and all are close in spec.

This is after almost 14,000 miles of pretty hard riding, but of course with regular $$$ supergrade synthetic oil changes.

I'm going to leave them alone unless someone can convince me I'm all screwed up. I'll probably check them again at 20k miles.

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dang sweat! 14K on an '06?? Soooo jealous.

Seriously, great to hear it's holding up so well. Yet another case for the Bonnie's superb reliability.
I bought it at the end of December, so it's 14,150 (I just checked it) in about 10 months, so that means an average of 1415 per month, or almost 50 miles per day!

I've been riding this thing.
I think you're ok leaving the valves where they are. Your readings are much like mine:
Exhaust - 30 30 30 30
Intake - 25 25 25 20
These were checked at 13300, shortly after returning from a 5k ride, where we ran Interstates at 75-80 for several hours. I'm pleased with how well the valves stayed in (close to in) spec. Like you, I'll probably run my bike a few more thou in the springtime, then do the shim thing.


[ This message was edited by: ohiorider on 2006-11-01 22:54 ]
Thats awesome! I have a lot of confidence in the Bonneville's
after hearing that.

Can you give your observations on chain and sprocket wear
tire wear and so on?

[ This message was edited by: Rocker1962 on 2006-11-01 20:33 ]
I got 8000 miles in 8 months. My engine doesn't sound too loud so I will probably leave my valves alone too. Valve clearance will open up because of wear & the clearance will close up because of valve seat errosion & valve wear. Good to hear that most are a little loose. You don't get as much valve opening so you get a little less intake charge but except for 1/4 miles times you would never know.
Good to hear.
I had a few valves that were .001 over max spec at 12,000 miles. Good enough for me until the 24,000 mile check.

At 18,000 miles I measured my chain sprockets as per the Haynes manual and it is still within the max stretch limit.

Even though I keep it oiled about every 400 to 500 miles, I still get rust on the outer edges due to all the rain I've been in the last several weeks. Yesterday riding up to Dallas I hit a hail storm that really put some pain to my thighs as the hail hit. I'm going to buy some thick, waterproof, insulated over pants today.
Rocker, I have changed my front sprocket from the stock 18t, to a 19t, back to the 18t, and then to a used (thanks Rodburner!!!) the mileage on the front sprocket is minimal, I haven't looked at the back sprocket in a while.

I replaced the back tire (stock on T100/Thruxton) Metzler at 10,000 miles and I probably could have gone 11 or 12k on it. So I have about 2k on my new rear and it's fine (of course), the front has 14k miles on it and may need replacing in another couple thousand miles. It's wearing evenly (no cupping) and still rides/handles great.

I've said it before, but CHANGE YOUR BRAKE PADS! I did my fronts with the upgraded EBC HH sintered metal pads about 5k ago and they're fine, but I just did the rears at 13k and there was literally nothing left on the pads. Nothing. The new pads grab so much better too, and at around 75 bucks for the whole deal and an hour's time it's definately worth it.

This bike rules, I've had really no problems other than stuff I've brought on myself, and that's half the fun!
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Those are great observations. I have 3000 on mine since early august. so far only a chain adjustment and tire pressure checks.
I did a valve check at 13,000 miles a couple months ago. 6 of the 8 valves were within spec; the two that were just a hair out of spec were the two outermost exhaust valves, which were tight by about .015mm. I called my dealer and asked him if he'd bother adjusting them if it were his bike, and he said no, so I didn't bother. I'll check them again when I do my late-spring oil change, and if they've gotten tighter I'll see about adjusting them.

Tight valves, particularly tight exhaust valves, need to be fixed ASAP. The exhaust valve needs maximum seat time to be adequately cooled. If the valve is too tight, it spends less time on the seat, overheats, and can eventually burn. Once it burns, it leaks and can take out not just the valve but the seat and head. (I know, I learned the hard way.)

Loose valves really aren't good either. They aren't as urgent, but should be fixed, at least at the recommended service interval. The cam profiles are carefully designed to gradually accelerate the valves when they open and gradually put them back on the seat when they close. When the valve gets loose, the cam hits the bucket too late and leaves too soon. The result is the valve starts to miss the opening and closing ramps and gets jerked open and slammed shut. That causes not just the extra noise from the parts getting hammered but also extra wear on the cam lobes, valve faces and valve seats.

It isn't that hard to adjust the valves (if you can get the shims) and keeping them where they should be is the difference between treating your bike like the pride of your garage or just a "beater" commuter bike.
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I don't think I treat my bike like a beater, so thanks for the positive comment. As the owner of my bike and the only person that matters, I'm willing to accept the difference in lash of .02mm-.03mm for now and I'll check it again in a few thousand miles.
On 2006-11-03 10:45, sweatmachine wrote:
I'm willing to accept the difference in lash of .02mm-.03mm for now and I'll check it again in a few thousand miles.
Thats OK for a few thousand miles. But although .02mm-.03mm doesn't sound significant, the specified gap tolerance is only +/-.025mm (~.001 inch). .02mm to .03mm over the upper limit is actually 180% to 220% loose. I put a chrome valve cover on my bike at 10,000 miles and checked the valves then. The valves were about like yours. I will get shims and reset them when I get to the official 12,000 miles service point.
I dunno my far left ehaust valve will do some tappin after a good ride. My friens America is talkin on both left exhaust valves regular. 10000k :)
On 2006-11-03 10:45, sweatmachine wrote:
I don't think I treat my bike like a beater, so thanks for the positive comment. As the owner of my bike and the only person that matters, I'm willing to accept the difference in lash of .02mm-.03mm for now and I'll check it again in a few thousand miles.

I tend to agree, and because the shim and bucket is not that precise and hard to change, I 'm going to hear them before I worry about them. But, like they say, whatever lets you sleep at night. :-D
Been reading a bit about the importance of checking valves. Several sites say to check it regularly so you can note if changes are occurring. From one site it says:

"Each time that one checks the valves, it is not to correct some small error, but to discover if the setting is changing between adjustments. Record any significant change and be sure to check it again in 1000 miles or so. If the change is measurable in 1000 miles, then something is wrong and you have found it before it failed on the road, at night and in the rain. Check it often and log the change. Get ready to spend money."

Some bonnie valves require that you angle (flex) a shim to get it into the valve. So what is lost is the true feel of how it slides in the valve. All I'm saying is the .001 off in the loose direction I think I am may be actually in spec if I didn't have to flex the shim into place. Maybe I need to try some angled shims.
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