Have a 2002 Road King FLHRI with 68k miles. Great bike, never had any trouble. Installed S&S 510G geared cams at 36k.
Lately I am hearing a knock? on start up. Lasts less than a minute and goes away. Sounds like it's coming from the front cylinder. Almost sounds like an exhaust leak, but checked pipes and exhaust nuts, all good. Wondering if it could be piston slap? I have run full synthetic oil since about 2500 miles. Yesterday, it did it on a restart while it was fully warmed up. Not the compensator, The sound is not coming from the primary cover.
Any ideas?

 

Could be a lifter i had one go bad sounded just like a motor knock

 

Knock sounds very harsh/loud. If it's a ticking sound could be collapsed lifter. Noise stops when it gets pumped back up. Hope that helps.
Russ

 

If it's not the compensator,and you have oil pressure. I hope it's not the same problem my friend had. Knocked bad at start up,found out it was a piston clearance issue

 

I agree with the others, Bad lifter.

 

Undo the plug wire (not sure it will run with one cyl) but if it will, see if it quiets down. If it won't run get someone to help & unplug both plugs & crank with a stethoscope. Does it look like it goes away once oil pressure gets up on the gauge (I know mine takes a few seconds to move).

Toby

Toby

 

I agree with RHillBilly. Had a lifter collapsing on my shovelhead. Scared the hell out of me sounded loud like a piston. Started as cold, only then as about a 100 miles racked up it took longer and longer to pump up and be quiet. Catch it doing it and pull the pushrod covers. if a pushrod has a ton of movement when that cam is not on the lobe its most likely that lifter.

 

If it sounds like an exhaust leak it's most likely a lifter, if you put in adjustable pushrods when you changed cams it's an easy fix. I'd replace them all, not with HD lifters, S&S, Comp Cams, or Gatermans are some of the best.

 

I got a 2012 thats done that from new. Its a lifter, no worries as long as it quiets right down.

 

Thanks for all the advice. Looks like I need to change the lifters.
I had one other thought. Could be carbon knock? I sprayed water into the throttle body several months ago, but it didn't seem to do anything.
Thanks again.