I'm bumping this thread back up again as this noise is still in play. I've since swapped out my baker compensator with a new one since I had the bad spring issue. I've also installed a baker primary chain adjuster and the chain is set with about 5/8" of free play when cold. Any ideas on this issue guys? Is there any way to isolate that the issue is piston slap other than an engine tear down? I can literally ride the bike for 20+ minutes before the noise goes away and then it's gone. I'm starting to fear that the pistons are the culprit. If the Pistons are slapping will this cause any engine damage? I don't know what else to do from here...

 

I also forgot to mention that I don't hear the noise at idle. Only when the engine starts to get under a load.

 

No it won't hurt anything it's just a annoying

 

The only thing that makes me think it's not piston slap is the fact that it doesn't do it at idle...

 

Harbor Freight and most big auto parts stores have stethoscopes. These have a probe and earpieces. You can press the probe onto something like the engine case, the barrels, etc, and hear where the sound is coming from.

Sound is weird, it can seem to come from somewhere other than the actual source.

 

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Is there any chance you mis identifying where the noise is coming from?

I say that because my bike had some knocking sounds coming from it at times you could accidentially think are engine sounds that i later found were issues with loose things inside bat faring along with loose mechanisms in vented lowers making a racket too.

Piece of wood or long dowel can be used to narrow down source of the knocking sound.

since if doesnt know at idle when hot will it know sitting still if you throttle up to & hold 2k-2,500rpm ish?

If yes try having a helper hold motor at rpm its knocks at while you search for source with wood dowel,could use dyno for that too if bike has to be in motion mode to make it knock.

Well since you say the noise goes away after the motor finally gets to full op temp its sure seems like it could be piston slap.

Motors that have piston slap cold that goes away when warmed up can go many miles with issues at all esp if they are not modded or abused with good oil maint.

For example,when new the wifes 98 olds with 3.1 v6 had piston slap on what sounded like 2 cyls that went away when warmed up. (Wrist pin can also sound a lot like piston slap too)

Broken piston skirt or ring groove land can cause piston slap which can be a result of detonation damaging/cracking the piton skirt or ring land,seen that cause piston slap type noise before too.

Fast forward to today ,our son now has the car and which just passed 208k miles when i just changed oil & filter and is still running very well using .5-.75 qt oil every 3k miles.

If it was a main or rod bearing issue the nose would not go away when hot that would likely get worse hot due to thinning oil & widening clearances lowering oil pressure .

BTW,Whats hot oil pressure @ idle and @ cruise in summer heat?

If its not a lifter noise either at this point i'd forget about it unless the bikes still under warranty or on EPS in which case i'd push the heck out of them to fix just because you have the coverage,not because its going to come apart any time soon which it hasnt done.

Good luck.

Scott

 

Give Jamie a shot...Usually piston slap is at idle when cold, and disappears when warmed up. Could possibly be a tuning issue in that area..

edit: Different piston to wall tolerances are used for different piston manufactures. Could be normal if in fact this is the problem

 

First of all, it ain't the oil, LOL!!!!!!!! That was funny guys, nice try though. Pistons slap, lifters clatter, rods knock.