Valve Shims & a 'tink, tink, tink' sound

[GLoweVA]

Okay, I know some of you are going to cringe, but I've got a slight 'tink, tink, tink' coming from my bike. It's most noticable at startup, and by the end of the ride (~30-45mins) it's almost not noticable.
So, recently I've put a new piston in #4 and new rings on all four.
I've got about 200 miles on them now, so the rings should be broken in just fine.
A while back I did some valve clearance measurments and my tightest one was at 0.1mm on one of the intake valves. (Spec is 0.16 to 0.2)
So, my question is, if the clearance is tighter, then the valve opens a little sooner and just a little bit more.
So, could my intake valve be tapping the top of my piston on the intake stroke?
I thought the crecent cutouts in the top of the pistons were there so the valve wouldn't hit.
Yesterday, I checked my compression and I got 160, 155, 150 & 140, so thats only 7% off the average of 151.
This weekend I plan on lifting the valve cover and checking the timing marks and adjusting the tensioner. (plus rechecking the torques on all the bolts from my mini overhaul)
While I'm in there, I'm going to remeasure the valve clearances again so I can figure out what shims I need. (looks like I might be able to reuse 3-4 of them)
I developed an excel spreadsheet that will do the calculations instead of using that crappy table in the service manual. If any of you want a copy, just send me a PM and I'll send it to you.

ps. When I pulled the plugs yesterday for the compression test, they were all grey/whiteish (ashy almost). So, I figure that means they're a little lean. I'll probably ease the idle mix screws out 1/2 turn.

[BA80]

It does sound like your running a tad lean from what you say of the plugs.

The tink,tink could be an exhaust leak at the haed.

[DAVINCI]

+1

Yeah, if a valve was tapping a piston, that cylinder would have 0 compression.

I have the same tink, tink and I'm of the opinion that it is an exhaust leak also, just can't find it

[GLoweVA]

An exhuast leak makes a little bit of sense, I had the pipes off during the overhaul. I did notice that one of the header pipes has an almost rust thru hole, plus I didn't have any new exhaust gaskets, just reused the old ones.
I thought that because the sound is more metalic sounding than a gas 'poof' sound that it was mechanical in nature.
I suppose I could try spraying some water mist around the pipes and see which way the wind blows so to speak.

Thanks for the info on the too lean thing. I'll try to post up a pic of the plugs this afternoon/evening.

[BA80]

+1
I have the same tink, tink and I'm of the opinion that it is an exhaust leak also, just can't find it

The Mac 4 into 2 I have on mine has a bit of a resonating echo in the single wall pipes that is a little more noticable when cold also.

[DAVINCI]

I think my leak is on the pipe at the weld between the flange and the pipe. It's the only thing that makes any sense. Although, i never think to check when i have the pipes off cause it's usaully in the middle of winter and the noise is a distant memory.

I thought it was a loose valve shim when I first heard it (2009), but the shims checked out OK. The noise is audible when it's really hot, like after an hour of summer highway riding.

[BA80]

I seem to remember someone posting a while back, a long while back, about an inner pipe rattling on a stock double wall system when cold also.

[DAVINCI]

This is not a rattle it's a precise half-engine-speed tink. Which is what made me first thing it was valve-related.

[GLoweVA]

I agree, but I don't know what the frequency of the tink tink is, it could be at the same rpm, half, or even double. I'll pay more attention next time I run it.
Here's a pic of my plugs. The lighting was a little off. (late in the afternoon), but you can see the greyness of the sooty type ash.

http://s1197.photobucket.com/albums/...gloweva/plugs/

[TopCatGr58]

The Metal Tink sound is often the sound of the valves closing shut, is more audible since it can travel thru the hole/leak. It's rarely a swoosh or puff kind of sound. Having to reuse your exhaust gaskets is most likely the culprit, they are made of corrugated/layered aluminum, and are like crush washers, but once they have been there for some time, under compression, and the exhaust heat, there's not much compressibility/sealing room/range left in them. A set of 4 are like $12.00 on PNM and such.

Your fourth plug....last one on the right....the center electrode looks more rounded off than the others as well. That film appearance on the outside of the electrode and such doesn't look right either.....but could be partially due to the engine/rings not being totally broken in/sealing??

T.C.

[BA80]

Yeah, a couple of those look pretty worn. Put a new set in and recheck.

The color looks a little light but that might just be the picture. Light tan is what your looking for.

[GLoweVA]

Those plugs have been in the bike for years. If you look closely, you can see all the rust around them. I don't have any issues with the socket grabbing them.
I plan on getting some new ones this weekend and putting them in. I might do the side gap mod on them next, next weekend. I want to see what the mileage on the new ones are first, so I can get a comparision.

Thanks TC, I'll get some new ehaust gaskets on order ASAP.

[GLoweVA]

Update on TInk noise

I started her up one day and bent down to find the 'leak'
Sure 'nuf there she was right on #3 near the bend where the pipe goes under the bike.
Stuck my ear up next to it and heard the tink/puft noise right from that hole.

So, next step (besides getting new pipes) is to wrap them old ugly disgusting rusty pipes with the exhaust wrap stuff from the auto parts store.
Sure it's not pretty, but it'll look a whole lot better than the rusty holey things i got now.

[natemoen]

That wrap will NOT plug the hole and will speed the rusting process.

[Shacknasty]

You will need to get that welded or get a new set of pipes. JB Weld is not gonna be yer friend either. Real weld!