S&S 107 engine "chirp" noise: and "rattle" noise fixed

[Fat_Bastard]

S&S 107 engine "chirp" noise

My 2004 Big Dog Chopper has an engine "chirp" on decelleration only, from about 2000 rpm or higher -- on a quick release of the throttle. It is a "single-chirp" that is about a second long. Doesn't matter if the engine is hot or cold (or if weather is hot or cold). There seems to be no loss of power or performance since 2004.

The engine/bike is original from 2004, has 26k miles and only started doing this about a year ago.

Things I have tried and know it is not (since no change):
a) Tightened/adjusted primary chain
b) Adjusted/aligned secondary belt
c) Loosened and re-aligned head motor mount bolts and bracket
d) Replaced exhaust manifold gaskets
e) Welded crack in stock exhaust pipe at two into one area
f) Cleaned and re-installed K&N air filter
g) Have always used 91 octane or higher gasoline
h) Changed engine oil & filter, use 20/50

I have not checked the compression releases ______ ?
* update: per another thread I just shot some WD-40 on both compression releases and turned them back and forth with the screw-head on top, manually plunged them up & down a few times; re-assembled with "condom-cover" and still chirps, no change...

Could it be a bad valve spring or valve seat _____?

Any ideas /comments much appreciated.

 

[bsauer]

I know you said you adjusted it, but that sure sounds like the secondary belt. I tightened mine, possibly a little tighter than spec, but the chirp is gone.

 

[blacktopper]

The first signs of head gasket failure is a "chirp" when the engine first fires on that cylinder when starting.

 

[Fat_Bastard]

The first signs of head gasket failure is a "chirp" when the engine first fires on that cylinder when starting.

Thanks "Black", head gasket sounds reasonable...

I thought somebody here once said run the engine stationary and shoot hair spray around it to detect a leak. Anybody realy do this or should I be the one to try it -- and blow up my garage!?:angry:

What is the best way to check it to be sure? _______

 

[Dakotabos]

Not saying it is in your case but my 04 Chopper "Chirp" was my Primary Chain. Readjusted and tightened front sprocket (Loose common issue on 04 Choppers)

You have to pull primary cover to check sprocket

 

[Fat_Bastard]

Not saying it is in your case but my 04 Chopper "Chirp" was my Primary Chain. Readjusted and tightened front sprocket (Loose common issue on 04 Choppers)

You have to pull primary cover to check sprocket

Thanks Dakotabos for PM and hot tip on Compensator Nut on front sprocket.

After researching and watching (listening to motors idle) on a few youtube videos, I think it is a loose Compensator Nut and/or worn Compensator; as you do...

(note: I have additional noise, from the left side primary case, like a bad bearing sound "rattleing" at 800 to 950 rpm, goes away at 1000 rpm -- that has been slowly steadily getting worse; along with the chirp on decelleration).

I will try the Compensator Nut first and let you know how that turns out this weekend.

 

[erldawg]

From your original post looks like you have already checked the top motor mount.
My K9 had the a similar chirping on left side and it was the top motor mount. I installed longer bolts on the coil cover and cleaned and reinstalled the upper bolt. Chirp gone. There should also be a insulator washer on the coil cover to head conection (if my memory is correct)

 

[woodbutcher]

on a side note, 800 rpm is way too low for the motor to be idling. it is starving for oil at that rate, need to bump it to at least a constant 1k.

 

[Fat_Bastard]

Engine Idle Rattleing Noise Fixed: Loose Compensator Nut

Thanks Dakotabos for PM and hot tip on Compensator Nut on front sprocket.

After researching and watching (listening to motors idle) on a few youtube videos, I think it is a loose Compensator Nut and/or worn Compensator; as you do...

(note: I have additional noise, from the left side primary case, like a bad bearing sound "rattleing" at 800 to 950 rpm, goes away at 1000 rpm -- that has been slowly steadily getting worse; along with the chirp on decelleration).

I will try the Compensator Nut first and let you know how that turns out this weekend.

Update Saturday 4-6-2013:
**ENGINE IDLE RATTLEING WAS FIXED:

found loose Compensator Nut; removed it with about 10 ft lbs. of torque!!!!, caught it before major damage... Removed, cleaned, retightened nut with High Heat Red Loctite to 150 ft lbs. **

Thanks to "Dakotabos" and "Woodbutcher" to send me down the right path.:2thumbs:

This video also convinced me of the potential fix since my "idle" rattleing noise was not quite as bad as this Harley; [which I believe also had a loose compensator nut] (see youtube link).
[ame=http://www.youtube.com/watch?v=Ayk4xg9gSS4]Harley Davidson Streetglide knocking engine - YouTube[/ame]

Now on to the original problem: Still have the "Chirp"

 

[DRBarnhart]

Now on to the original problem: Still have the "Chirp"

This is probably way out there but could it be coming from the gas tank rubber mounts?

Dennis

 

[Jabb]

My bike was doing the same thing.I asked the guys at BD they told me it was the back pully getting dirt and dust between it and the belt. On the 04s the did not coat the puppy's with Teflon. The solution to the problem is to change the rear pully or buy a can of Fuchs pro prep silkolene hard surface conditioner. Spray to on your belt about every 500 miles and it will fix the problem

 

[1mndg]

A little WD40 on the final drive belt will get rid of it for awhile. It's dirt between the belt and pulley.

 

[Dakotabos]

very cooooool you got it before damage

 

[Fat_Bastard]

Chirp Noise: Solved, was Secondary Belt & Sprockets needed Lube/clean

My bike was doing the same thing.I asked the guys at BD they told me it was the back pully getting dirt and dust between it and the belt. On the 04s the did not coat the puppy's with Teflon. The solution to the problem is to change the rear pully or buy a can of Fuchs pro prep silkolene hard surface conditioner. Spray to on your belt about every 500 miles and it will fix the problem

I retried many other things twice from my original list of probable causes and potential fixes.

I noticed that after washing my bike, I took a quick ride (this time) while it was somewhat wet and the "chirp" was gone for about 5 minutes, or 2~3 miles of stop and go riding... Chirp came back; I didn't think much of it either way...

** CHIRP NOISE FIXED:
But then I decided why not try what "jabb" said. (I had tried other silicone sprays and lubes months before but no change) So I finally found some 'Fuchs Pro Prep Silkolene Maintainer' spray. Sprayed some on, wiped some dirt off and a little excess and rode about an hour -- NO CHIRP !!!!!! **

Thanks "bsauer", "1mndg" for steering me in the right direction and a special Thank You to "jabb" for the fix.:up:

This forum is awesome! and has kept my bike runing while saving me thousands on repairs!

Fat_Bastard is now a Happy Bastard and Chirp Free!

 

[Five Five]

Lets go riding you fat bastard. I will buy you a big lunch

 

[awg]

Mine to had a chirp when I would let off the throttle fast. I to adjusted my primary chain (which was loose) and my rear belt. And it to went away.

 

[reloaderbmg]

my road king was making the same noise, its the front engine shock , look under front of engine, [you can rattle the shock from down there! new shock & mount kit

 

[Fat_Bastard]

Lets go riding you fat bastard. I will buy you a big lunch

Hey 5 5,
I'm down for that bro; In and Out Burger: "Double-Double";
Oh U buyin' -- then make it a "4 x 4 Animal Style"

Yeah, lets ride again, want to check out your new ride
(and see that you can fly right again from that hit-n-run job).

Maybe we can get "Bar Hopper" too -- heard he likes to get first round :lol:

 

[Jabb]

Glad I could help

 

[seymour]

Had the same annoying chirp on my big dog.. took it in thinking it had something to do with the exhaust was going too have new pipes put on. However left with the same pipes but a newly welded exhaust bracket. Read through a number of forum posts pertaining to "chirps" and went ahead and tried what seemed to easy to be the solution... $5 can of belt dressing from the parts store did the trick! No more chirp