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More than the usual tappet noise.
Posted: Tue Sep 11, 2012 1:22 am
by SteveD
The right valve area has a loud metallic sound (like an exhaust leak).
I'm heading to the shed now to take off the exhaust, the right rocker cover and check everything. It all looked ok last week when I did the valves. Inlet was set at 0.13, exh at 0.18.
The end float on the right exhaust rocker block was loose which I corrected, so I'm going to recheck that. Fixing it last week didn't change the noise.
I'm wondering if a bit of carbon is under the valve lip or if the headers aren't seating right or maybe the header compression ring hasn't closed properly?
Other possibilities?
Re: More than the usual tappet noise.
Posted: Tue Sep 11, 2012 2:47 am
by ME 109
Was the noise there last week before you reset the valves?
Re: More than the usual tappet noise.
Posted: Tue Sep 11, 2012 2:57 am
by Major Softie
ME 109 wrote:Was the noise there last week before you reset the valves?
SteveD wrote:The end float on the right exhaust rocker block was loose which I corrected, so I'm going to recheck that. Fixing it last week didn't change the noise.
That certainly makes it sound like it was.
Steve, if you already discussed this valve and rocker adjustment in another string, could you quote that here, or at least give us a link to the other string?
Re: More than the usual tappet noise.
Posted: Tue Sep 11, 2012 3:07 am
by Deleted User 62
Push rod touching the edge of the tube? If you used a clamp to hold the rocker blocks whilst torquing, it's weight may have lowered the whole assembly. Another possibility is pinging or pinking, which can sound very metallic. Does it do it just under load, or at all times?
Re: More than the usual tappet noise.
Posted: Tue Sep 11, 2012 5:31 am
by SteveD
It does it at start up. Loud when cold. I suspect this started after I changed my mufflers. That was the previous task done on that system. Maybe shoving them on pushed the header forward? I noticed it after not having earplugs in at startup. I usually kit up, start and ride, so without the earplugs maybe I've heard something that's been there for a while?
The valve settings were fine today, the rocker body correct and the pushrod not touching anything.
The header was about 4mm out from resting correctly in the head, and the compression ring seemed to have allowed a small leak. There was evidence of blow by at the compression ring where the gap should close after tightening the star nut.
I'm unsure if this is the cause of the noise though, but tomorrow I'll loosen the whole system and ensure both headers are equally seated. I'll also get some sealant and judiciously spread it into the gap and see if that helps.
MS...this was mentioned I think but not discussed further.
Re: More than the usual tappet noise.
Posted: Tue Sep 11, 2012 8:44 am
by lrz
I've had a loose exhaust nut convince me that my left head was about to implode...
Re: More than the usual tappet noise.
Posted: Tue Sep 11, 2012 9:52 am
by Duane Ausherman
When one sets the side for valve adjustment, the pushrod is at the point when it is least likely to hit. It can still be too low and hit during the cycle. During the running cycle the pushrod actually moves up and down at the point where it enters that hole. Probably not your problem, but need to get this info out there for those who care.
Re: More than the usual tappet noise.
Posted: Tue Sep 11, 2012 10:09 pm
by SteveD
Thanks Duane.
When I was looking for tdc, rotating the rear wheel, I did a couple of cycles where I watched the pushrod move and it didn't touch the pushrod tube. It appeared to get to 12 o'clock closer than it did to 6 o'clock, but there was still a mm or so of clearance. Worth measuring that?
Re: More than the usual tappet noise.
Posted: Wed Sep 12, 2012 12:21 pm
by Deleted User 62
Piston slap?
Re: More than the usual tappet noise.
Posted: Thu Sep 13, 2012 8:56 am
by SteveD
Tim Shepherd wrote:Piston slap?
Hmmm, I hope not. Nicasel bores get that do they?
It is loudest at start up, but does persist even when warm.
Gooping up the slight gap in the header compression ring didn't reduce the noise either. I was hopeful it'd be something simple.