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Engine Mechanical TopicsDiscussion for motor builds, cams, head work, stripped bolts and other engine related issues. The good and the bad. If it goes round and around or up and down, post it here.
Since several years I have had a clattering noise coming from the left side at load. I have been thinking primary, but now I believe it is valve train noise.
When doing the big bore two years ago I discovered witness marks on the rocker assembley bolts, took some shots of them, then forgot about it.
Anyway, now l am pretty sure it is the rocker arms making this disturbing noise, (rotating back and forth against the bolts), and I will install rocker arm lockers this winter.
My question is: Can this gap affect performance and cause other troubles?
Thanks in advance.
Best Regards
Oak Mountain Rider
P. S. Dont think it is pinging - no knockcounts and this happens all the time at all engine temperatures. And dont think it is from the primary - 0.0028 runout measured on the compensator bolt, new SE Compensator and new primary chain tensioner (upgraded C-version).
Last edited by OakMountainRider; Aug 14, 2025 at 02:11 AM.
no performance issues would come from it. Get a cheap stethoscope and find exactly where the noise is coming from. Could be the rockers, could be the rods touching the tubes, could be a few things. Sounds tend to bounce around
no performance issues would come from it. Get a cheap stethoscope and find exactly where the noise is coming from. Could be the rockers, could be the rods touching the tubes, could be a few things. Sounds tend to bounce around
Thanks for your reply. Yes, just received a stethoscope for recording. And will do a couple of recordings.
Just did two recordings with an electronic stethoscope to my Iphone. However it was just a lot of noice as the soundtracks were completely overloaded. I think I need an app where I can control the recording volume, because now it is too distorted. Anyone here who has done this with an Iphone?
Just found the app Voice Record with gain control. Will make another try.
Last edited by OakMountainRider; Aug 14, 2025 at 03:40 PM.
An electric stethoscope? WTF haha never heard of such a thing. Below is what I was referring to. You touch the end of the probe in different areas to isolate where the noise is coming from, usually where its the loudest and/or the tapping is the hardest.
An electric stethoscope? WTF haha never heard of such a thing. Below is what I was referring to. You touch the end of the probe in different areas to isolate where the noise is coming from, usually where its the loudest and/or the tapping is the hardest.
I already have this type of stethoscope. As I have written above the noise is only audible at load, which means I can only hear it when riding the bike, and trying to use this stethoscope while riding, (in traffic without a helmet), would put my life and others in danger.
So this is why I intend to use an electronic stethoscope, which I can tape on the rocker boxes with duct tape and then record the sound on my Iphone. If it will work I do not know yet, as the stethoscope is made for heart and lung sounds.
I will come back in this thread and report how it goes.
Last edited by OakMountainRider; Aug 17, 2025 at 05:49 AM.
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Valve train noise
