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[woohoorider]

I have a chirping noise on my newly rebuilt 110" motor, '07, (new crank cases, crank, top end, rings, cams, lifters, etc). After 2000 mi. and 3 oil changes(checking for metal, zero debris thus far), I have developed a chirping noise. I read a post earlier from someone with a similar noise in the 2k to 3k rpm range, same as mine, and some replies referred to a twisted crank , thus a brass bearing gone on con rod or crank end. I have zero debris so I;m leaning toward an exhaust leak(I hope hope hope), And have HD mechanic friends that feel it's a possibility. How can I check for a leak at the heads for this exhaust leak with motor running? Thanks in advance.

[Ricks903]

You can spray brake cleaner where the pipes connect to the head while it is running and see if that makes it miss or stall, indicating a leak.

[HDDOCFL]

If you can hear the chirp at idle, you should be able to feel the leak with your hands cold engine. very little time to do this until things get to hot to feel.  You can also use smoke  incense, punk, ect.   Doc  You can spray for an intake leak at the intake seals.

[SneakyPete]

Unless you are getting some decel pop from the exhaust I doubt this "chirping" noise is from an exhaust leak at the heads.  You don't mention what type of pipes you have, but I had a similar noise on my bike, thought it was coming from the cam chest, turned out it was a broken exhaust bracket where the headpipes mount to the transmission cover.  Wasn't obvious as it was difficult to see, but just put my foot on the exhoust pipe when running and the noise disappeared!  Since motor was recently rebuilt could be some misalignment of exhaust pipe. 

[sadunbar]

You can spray brake cleaner where the pipes connect to the head while it is running and see if that makes it miss or stall, indicating a leak.

DO NOT SPRAY BRAKE CLEANER ON A HOT EXHAUST!

The fumes are extremely dangerous!  Read this...

http://www.brewracingframes.com/id75.htm

[MikeV]

DO NOT SPRAY BRAKE CLEANER ON A HOT EXHAUST!

The fumes are extremely dangerous!  Read this...

http://www.brewracingframes.com/id75.htm

Wow, that's crazy. Thanks for posting that.

MikeV

[Heatwave]

DO NOT SPRAY BRAKE CLEANER ON A HOT EXHAUST!

The fumes are extremely dangerous!  Read this...

http://www.brewracingframes.com/id75.htm

Unless you are getting some decel pop from the exhaust I doubt this "chirping" noise is from an exhaust leak at the heads.  You don't mention what type of pipes you have, but I had a similar noise on my bike, thought it was coming from the cam chest, turned out it was a broken exhaust bracket where the headpipes mount to the transmission cover.  Wasn't obvious as it was difficult to see, but just put my foot on the exhoust pipe when running and the noise disappeared!  Since motor was recently rebuilt could be some misalignment of exhaust pipe. 

I agree with this view. Before taking anything apart or spraying anything on the engine, take a screw driver and tighten all exhaust pipe clamps and inspect the exhaust brackets to see if any are broken. I would also recommend tightening the nuts on the exhaust studs at the head. If any of these are loose they can cause a chirping sound they sounds like its coming from inside the engine when in fact its coming from the exhaust. Good luck!

[dayne66]

Unless you are getting some decel pop from the exhaust I doubt this "chirping" noise is from an exhaust leak at the heads.  You don't mention what type of pipes you have, but I had a similar noise on my bike, thought it was coming from the cam chest, turned out it was a broken exhaust bracket where the headpipes mount to the transmission cover.  Wasn't obvious as it was difficult to see, but just put my foot on the exhoust pipe when running and the noise disappeared!  Since motor was recently rebuilt could be some misalignment of exhaust pipe.  

I second this...I had 'birds'...not consistant..depended on engine temp, and strangely enough, ambient temp as well....was a cracked exhaust bracket tucked in an awkward spot to see. Searching for the cause, at Heritage HD in Edmonton I was told by Charles the sevice manager that to look any further would be 'on my dime' even though the bike was a month old, and they installed the pipes and other accessories.

[catz66]

Here is an easy way to check for an exhaust leak. Get a few feet of vacuum hose. Hold one end close to your ear (NOT IN IT) and then run the other end around the head pipes at the cylinder heads. If there is a leak you will hear it through the hose. You can also use this to find squeaks and vacuum leaks. JUST DON'T TRY TO DO THIS WHILE RIDING. Might make for an interesting news article. 

[Doc 1]

Here is an easy way to check for an exhaust leak. Get a few feet of vacuum hose. Hold one end close to your ear (NOT IN IT) and then run the other end around the head pipes at the cylinder heads. If there is a leak you will hear it through the hose. You can also use this to find squeaks and vacuum leaks. JUST DON'T TRY TO DO THIS WHILE RIDING. Might make for an interesting news article. 

This method is the best.....you can hear even the slightest leak this way. I take the end off my stethoscope and use it....works fantastic.
Doc

[2harleys]

You can spray brake cleaner where the pipes connect to the head while it is running and see if that makes it miss or stall, indicating a leak.

Spraying carb or brake cleaner on a leaking INTAKE will cause the engine to raise or lower RPM depending on how bad the leak is, but it will have no effect on an EXHAUST gasket leak.

[dlaws01]

I use a stethoscope like Doc said except mine has a 1/8" diameter metal rod approx.  12" long that allows me to get into tight spaces without getting burned or too close to moving parts.  I think I got it from Matco or Snap On and it has proven to be a great diagnostic tool for finding all those strange little noises our machines like to make.  It cost about $15.00 but its worth a fortune when you need it.

[Unbalanced]

Can pickup a cheap stethoscope at harbor freight as well.   For intake leak you can try soapy water as well.

[Ricks903]

If you cover the exhaust with a piece of cardboard while the bike is idling and spray the head pipe where it connects to the head with brake cleaner,if you have an Exhaust leak, it while cause the engine to stumble.The exhaust valves are not completely closed when the piston begins its downstroke,sucking in the cleaner and causing the engine to stumble.

[sadunbar]

If you cover the exhaust with a piece of cardboard while the bike is idling and spray the head pipe where it connects to the head with brake cleaner,if you have an Exhaust leak, it while cause the engine to stumble.The exhaust valves are not completely closed when the piston begins its downstroke,sucking in the cleaner and causing the engine to stumble.

I stated this earlier in the thread, but it is worth repeating.  Do not spray hot exhaust with brake cleaner.   The fumes are higly toxic!!!  The damage the fumes can cause are immediate and very serious!!