Super low idle knocking/slapping

[Brent Duncan]

oh I didn't leave it to idle that low at all , as I said I was just fiddling around and noticed the noise is very loud in comparison to the std noises the engine produces at the proper idle. just asked.

[49Reo]

...if it ain't broke don't fix it...

[Troll]

91,000 miles (146450.304 Kilometers) on mine,now, and nothing has changed...noisy when cold, gets better, and sometimes it's mechanically silent. I know I have one hydraulic unit that has a problem. This is a left over from the previous owner, who never changed oil and left the bike sit for 4 years in a barn with what ever that black tar stuff was in the crank case...No complaints, it's just the way they are. Someday, I f I ever get rich, I'll pull the engine and replace all the hydraulic units, but for the foreseeable future....naaahhh.

[capnconch]

when i turned the idle down low past normal idle to the point of the chug there is a health slapping almost knocking is this normal with super low barley running idle??? i know the bikes are not supposed to idle that low as it pretty much dies on twist of the throttle. but is the slapping/knocking just a cause of abnormally low idle? I'm not letting the bike idle at this low rate as it doesn't even stay running if you hit the throttle and upon release dies and won't restart unless idles is turned up to proper mark. just want to know if the noise is normal because of poor mix/low idle.
[/quote]

Not a good thing to turn the idle down that low! You need oil pressure to maintain good lubrication and when idling to damn low you are starving your engine for oil. I bet it does get noisy, might even FIU... Put the idle back up to 800rpm + I would never run my 1500 that low. Mine has a lopey idle and is where the rpms belong.

[jmbo]

I agree that while it bothered me at first, I soon realized that all was well in that cacophony we call and engine. Mine one had 12K on the clock when I got it so I new it wasn't worn out. Mine clatters like a D9 Cat at start up on a cold day. Then once running yoyu let the clutch out in neutral and it just gets worse. Park my butt on the seat and it's amazing that once you hit  80 all those noises turn into a sweet purr.

[Brent Duncan]

no i think that analogy sums it up a coffee can full of rocks lol love it. its just when the idle is to low as i was just messing around and seeing how low i could go with the idle but not an idle i would run it at by any means it sounds like its going to blow up lol it totaly goes away when put back to the appropriate idle. lol thank you Troll, again you put my mind at ease thank you.

[Troll]

This is a pretty busy engine. I'm not sure, but I'll bet what you hear are the decompressor cams bouncing around, and maybe a little timing chain slack. Mind sounds like a coffee can full of rocks when the idle is too low, and sometimes one of the hydraulic units will make some noise, even after it's warmed up. 90,000 miles, now and noises included, it runs perfectly!

[Brent Duncan]

oh i know the bike is noisy when cold, but this is well warmed up and i was turning the idle down just playing with it and when it gets very low there is a real almost piston slap knock when chugging close to dieing. i was turning the idle down just to see if the bike will chug like a Harley does but when it gets down really low to the pint of almost conking out there is a really noticeable knock almost like a piston slap. this is after 15mins of the bike being warmed up, like i said i was turning the idle knob down just playing around to see how low the bike can idle.

[Troll]

In a word, yes...and the colder it is the worse the noise. When it's around 30 here, the thing sounds terrible until it warms up.

[Brent Duncan]

ok here is an odd question, bike is running fine with the exception of small leaks at the cam plugs but going to fix those asap.lol
Started the bike today and was laying around wight he low ice knob by the right air filter cover, and when i turned the idle down low past normal idle to the point of the chug there is a health slapping almost knocking is this normal with super low barley running idle??? i know the bikes are not supposed to idle that low as it pretty much dies on twist of the throttle. but is the slapping/knocking just a cause of abnormally low idle? I'm not letting the bike idle at this low rate as it doesn't even stay running if you hit the throttle and upon release dies and won't restart unless idles is turned up to proper mark. just want to know if the noise is normal because of poor mix/low idle.