very loud noise from heads

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Sep 20, 2018 | 12:33 PM

Zoom1077

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From: Minneapolis

very loud noise from heads

Hi, I have a 2017 SGS with about 15000 miles. Bike is stock except for ventilator air cleaner and harley tuner. I took a trip recently and during a couple of inital start ups I heard a very large noise almost like a hammer striking the top of the motor. After a few seconds it stopped. Bike ran well the entire trip but the noise was very concerning. Once home, I changed the oil and all was fine until yesterday when I started the bike after seeing a movie. Again, very loud noise like a hammer hitting the heads. Noise disapated after about 10-15 seconds. This only occurs sporatically as most start ups are normal. All three times the bike has been outside and not in the garage. Any chance my open air filter is drawing in moisture although filter has been on over a year?

I've read some past postings in regards to this but no one really pinpointed the issue. I have made an appointment with dealer who says it could be the pump, but if that were so would it run well after a few seconds?

Has anyone had this concern and found out why? This noise never occured until about 13000 miles and is awful sounding on start up. I have trouble accepting this is normal and not damaging the motor? Suggestions??

Sep 20, 2018 | 03:35 PM

Max Headflow

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From: poway

You got a lift bleeding down when the motor sits.

Sep 20, 2018 | 03:58 PM

Jackie Paper

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From: Honah Lee

Are you referring to a startup clunk these V twins are famous for? If so, sounds like your battery cables are a little loose. This makes for a poor connection letting the motor kickback since the starter is weak. Check cables and also might as well remove the battery and charge it 24 hours and have it load tested.

Like MAX says, also, a lifter bleeding down will make you think you have a rod knock and it is going to blow up. Whenever I have to turn motor a lot working on one with no oil in it, I never start it up with owner around the first time.

Sep 20, 2018 | 05:36 PM

Zoom1077

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From: Minneapolis

It does sound like a lifter that has bleed down overnight . How is that fixed? Sounds awful first few seconds. Thanks for the answers.

Sep 20, 2018 | 07:50 PM

Max Headflow

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From: poway

Typically replacing the defective lifter corrects the issue. HD lifers are known for not being the best..

Sep 21, 2018 | 06:30 AM

prodrag1320

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From: deland,florida

good time to get in the motor & replace cam bearing & lifters,

Sep 25, 2018 | 07:13 AM

Hillsidecycle.com

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As already said, sounds like a lifter bleeding off, and the valve lash is being heard via the pushrod ball end, dancing in the rocker arm cup, echoing in the rocker covers.
We'd suggest to replacing with a top quality lifter, such as an S&S, and with an adjustable pusrod, load the lifter to .140".
Replace the inner cam bearings at the same time to prevent headache further down the road.
Scott