Engine Noise

[IanDMacDonald]

https://www.youtube.com/watch?v=4KLQ...ta_playerounds I won't call it a knock. I googled what an engine knock sounds like. It does not sound similar, it only does it at idle. I read a thread last night about an indescribable engine noise that ended in catastrophy. My noise makes me nervous. I would says it sounds similar to a car chugging before it runs out of gas. The sound can be heard in the first ten seconds. At-first I thought it was lower-engine. However, I tried the broom handle trick, and it almost sounds like it's upper engine. Engine runs great. It worries me though

Forgive the dirty engine, it will get paint in the Winter.

[James England]

Noises are difficult to detect on videos but.... I hear a normal sounding cam rustling sound, a gurgling, gulping sound from the carbs as if the air filters are non OEM?

Starting at 42 seconds, there's a metallic ringing sound?

I'm wondering if your cam chain tensioner is operating correctly? Have you checked it?

There's the possibility that the primary chain is slapping about. These kind off things show up at idle, especially if the tickover is uneven due to incorrectly balanced carbs. Then, when the engine revved, the slack is taken up and the noise goes away.

My XS1100 made a similar noise at tickover which disappeared when I balanced the carbs

[IanDMacDonald]

The gurgling sound is the one that has me worried. It leaves me with goosebumps. I have a modified airbox. I'm not aware of my ACCT not doing it's job. I'm not familiar with sounds an engine makes with bearings going, etc. My phone has a very sensitive microphone. I believe the tinging was when I held the phone right upto one of the cylinders. And, the only thing I can guarantee is the carbs are synced, not necessarily tuned properly. Gotta re-check the plugs soon. Thanks for the reply and things to think about.

[D0wn5h1ft]

That slapping sound is definitely your cam chain slapping around a bit. I just installed a new cam chain tensioner gasket and after properly setting the chain tensioner my slapping sounds went away. From what I understand, its a good idea to reset that cam chain tensioner if it hasn't been done for a long time since that chain will stretch over the years (refer to the last part of "head removal and assembly" in the manual for how to do this, it normally takes taking the valve cover off). As far as the gurgling sound is concerned, have to re-tightened your exhaust flanges as of late? I know with mine I have to torque them down occasionally because vibrations/heating and cooling tend to have them work their way out (since I don't know of any lock-tite that can withstand those temperature without burning).

[IanDMacDonald]

I just watched the video again. At the 45 second mark, I had the phone next to the timing cover with a hole and crack in it, so it was the timing wheel you heard.

As far as the CCT, I have an ACCT that I re-installed on there in June. I have tightened the exhaust nuts here and there, and they stay tight. And, Locktite does make a high temp formula, depending on whether you are "joining" or "bonding" the metals, the numbers are 620 and 680 respectively.

If James is right, the gurgling is from not having a factory box. I hope that's the source. I just don't want it to be something else and have a hole in my case down the road. Oil level will hopefully be my savior with this engine.

[fredintoon]

I just watched the video again. At the 45 second mark, I had the phone next to the timing cover with a hole and crack in it, so it was the timing wheel you heard. - - -

Hi Ian,
this hearing impaired old guy can't help you here but my dear ol' father-in-law used to claim he could get another 40,000 miles out of his Hillman Minx engine if he turned his hearing aid off while driving.
Then there's the Bugatti urban legend I just sent to Rasputin:-
Dear Mr Bugatti,
my engine sounds like a bucketful of ball bearings being poured onto an iron plate.
Dear Customer,
from what you say, your engine is running perfectly.

[IanDMacDonald]

Lol, yeah that made me laugh Fred. I just don't know enough NOT to worry, yah know?

[motoman]

May wanna pull the left-side timing cover, start the bike and watch to see if that vacuum advance diaphram is doing the dance thing at an idle or not.

[natemoen]

Didn't you go back to the pinned fixed advance unit Ian?

[IanDMacDonald]

Fellas- Yes, I did go back to the modified advance. The noise was present before and after the advance mod. I went back to the advance mod for performance reasons.

But, right now I still have the hose going to the #2 carb. I'll block it off both ends since the advance is locked-out at full advance.

It's a different noise. Hard to explain. Only heard during dle. I don't want to ever have to crack the case on the engine. But, I at-least want to know if my engine is a ticking time bomb.

[mikubuilder]

I see you're one of guys who don't leave a stone unturned....me, on other hand, got my bike to "good enough" and just enjoy ridding

[IanDMacDonald]

Well, I've made some dumb mistakes working on this bike caused by ignorance and impatience. I just want to learn this bike well.

[petejw]

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[TADracer]

Like was said before it is really hard to judge something by a sound that is recorded. So, the only thing I hear is that you have a valve ticking (over by #4) but that can be normal too provided your valve gap is still within limits.

As far as the chugging, it merely sounds like your idle is set too low or maybe your initial timing is to retarded at idle (or both). Mine sounds similar to yours when I drop it below 1000 rpm and set the timing to 5 degrees (stock for my SF).

[IanDMacDonald]

Thanks Mike. I'll just ignore it and keep the bike filled with oil. Got plans to give her the spa treatment over the Winter with Honda coils, paint, etc