Dull knocking sound
#11
09-01-2022, 04:35 AM
Road Captain
sound can play tricks on you,
you can swear blind a noise is coming from the front but when found, it was coming from the other end,
try taking the bike to a bumpy hill, & freewheel it down with the motor off to see if you can hear anything, you'd be surprised what you might find,..pump the brakes to check their mounts. check for lose calipers, worn shock bushes, lose motor mounts, ehausts, fenders, broken tank mounts etc, etc etc,....
once all else is elimited then look at getting the motor torn apart & check it out,...do the easy simple things first,
once had a buddy do a full motor re-build only to find the calipers were lose !!
you can swear blind a noise is coming from the front but when found, it was coming from the other end,
try taking the bike to a bumpy hill, & freewheel it down with the motor off to see if you can hear anything, you'd be surprised what you might find,..pump the brakes to check their mounts. check for lose calipers, worn shock bushes, lose motor mounts, ehausts, fenders, broken tank mounts etc, etc etc,....
once all else is elimited then look at getting the motor torn apart & check it out,...do the easy simple things first,
once had a buddy do a full motor re-build only to find the calipers were lose !!
#12
09-01-2022, 05:59 AM
Hi guys. New shovelhead owner here. It’s a 1980 Flh supposed to be a low mileage but who knows! The screws on right hand side of the engine have never been touched. Couple of oil minor oil leaks but nothing serious. My question is that I have a dull knocking that sounds like piston slap on acceleration especially between 40 and 50 mph. Is a small amount of piston noise acceptable on a shovel? I don’t have another shovel to compare it to. Ireland is a strange place, nobody seems to want to help out. I’m not new to Harley Davidsons or motorcycles and I always do my own work. Thanks
#13
09-01-2022, 06:18 AM
Stellar HDF Member
Piston noise is usually louder when cold because the piston expands as it get hot. So is the noise different, louder etc, when cold? And, can you hold the brakes and load the engine when in gear to get a better idea when the noise starts?
Other things that cause noise will also change with temp, but with a lose fitting piston that is "slapping" in the cylinder the sound should change from cold to hot.
Paul
Other things that cause noise will also change with temp, but with a lose fitting piston that is "slapping" in the cylinder the sound should change from cold to hot.
Paul
#14
09-01-2022, 01:47 PM
Seasoned HDF Member
I went over the engine with a home made stethoscope last night and front and rear top ends make the same tapping clicking sounds, barrel and bottom end sound quiet. Intermittent knock or slap in primary. Chain is adjusted properly and engine nut was removed cleaned and torqued about 700 miles ago.
I have a chance to ride another shovelhead in the next month or so so I can compare noises.
One thing. Could the sound in hearing be induction noise? Thanks for all the help.
I have a chance to ride another shovelhead in the next month or so so I can compare noises.
One thing. Could the sound in hearing be induction noise? Thanks for all the help.
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Crankpin2ie (09-01-2022)
#15
09-01-2022, 02:37 PM
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