Hey everyone. Recently picked up a 78 flh. So here’s the thing, the bike makes a pretty shaky rumble type noise when running. been doing a lot of research as to what it could be and I’ve found that it may be rocker endplay or also piston slap. Does anyone have any ideas? Thanks a ton. Here’s a video of the noise.
1978 Shovelhead top end noise
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I’ve done this and can’t quite seem to tell what I’m actually looking for, this is my first BT. I guess what I should ask is if any of you guys have any guesses as to what it could be before I take it apart? Going to start with rocker shafts and work my way down, but it would help to have some more insight. Thanks again!Comment
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Rocker arm end play spec is something like .004 - .025, so don't bother with that. You won't hear the rocker arms anyway.
If you suspect that the valve train is the source of the noise, remove the tappet blocks and check the tappet rollers and cam lobes carefully.
A steady knock at idle that goes away as rpms increase is often due to a worn compensating sprocket, or a loose motor pulley if the primary is a belt drive.
A galled piston will usually make a noise that is more of a "tink" than a "clunk".
JimComment
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I'll drink to that ...
Since this scoot is a unknown to you ...
Why not tear it all the way down, get to know it type deal ...
Ya might see the needs for some upgrades along the journey ...
... /// https://youtu.be/QDYwLhgHl64 \\\ ...Last edited by Dragstews; 08-20-2021, 1:42 PM.Take my 45 and outrun em all ..Comment
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Hey we have the same last name! And I agree drag, just thought I’d check with the cc wizards. Going to hustle it over to born free next weekend then it’ll be tear down time after that. I’ll post pics for anyone willing to lend a helping hand.Comment
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The compensator should have some give when the chain is rocked back and forth (that's its function). The cover should be tight, and if you can rotate the cover by hand, that indicates wear at one or more places in the assembly. Many people have good luck with just replacing the compensator with a solid sprocket. That is a cheap fix nowadays, as factory compensator parts are hard to come by, and a lot of the import stuff is junk.
JimComment
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JimComment
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That's the cover, it has a stack of belleville washers in it that provide the spring pressure. If the cover can be turned easily by hand, the assembly has enough wear that it might make noise. Just for simplicity's sake, you might want to do the solid sprocket conversion, it's not expensive.
JimComment
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