Weird noise after rebuild

I just finish my engine rebuild and it runs really good. One thing i did notice after the rebuild though was a slight ringing noise. Best way to describe it is, it sounds like my keys in the ignition is vibrating on the handlebar. I thoughts thats what it was but i made sure my keys weren't touching any metal and it was still there. It is very quite. I can only hear it at idle but I have a loud exhaust so I cant say if its occurring at cruising speed. Im not sure if its bad or not, just never noticed it before. The engine runs like a champ though. And as a reminder, ALWAYS RETORQUE YOUR HEAD BOLTS AFTER FIRST WARM UP. I found mine to be all loose and some were off a total of 2-3 ft pounds. Im sorry if this description is crappy but i cant think of another way to describe it.

Mine does the same thing, I figure it is the cam chain being loose. Mine needs to be replaced so I am not worried, did you change the cam chain? If you did have you checked the cam chain tensioner? Mine goes away when the engine warms up.

I am going to pull the tappet cover and have a look at what is happening with the engine running, it could be an oil supply thing because mine started doing this when I replaced the sump after repairing the Starter clutch.

Noel

You mentioned rebuild, engine in or out of frame?

If out, re-torque all your engine to frame bolts as well...
As in my case, found several of them loose after 50 mile break in time frame.... Hell, the back long bolt was just sitting there 3/4 in where the nut back spun and was gone... :S

Ran this by Plum & Larry and they both replied the same, this is common and expected...

Garden hose or stethoscope around the engine case while idling...

Just a thought....

OMR

No i did not change my cam timing chain. It shouldnt be loose but who knows. i didnt think about checking torques on my engine mounts cause i did take the engine out of the frame. and im not sure if the sound goes away after a warm up. I have only put 50 miles on it=2 trips. so I havent really payed much attention.

I took mine for a blast today and the noise it definately there when I start and let her warm up, after a 20Km ride the noise was gone. I have been reading about the auto cam chain adjuster loosing tension, it sounds possible this could be my problem. Do you have an auto adjuster on your bike? I might look into a manual adjuster, at least with an air cooled engine I can hear the chain rattle and when I should adjust it.

Noel

If the sound goes away when hot, then it is likely a clearance issue between two components.

Could just be a slightly large gap on one of the shim/valve clearances.

I say, ride the sucker. :laugh:

GL.

Sound does not go away when engine is warmed up. its probably a loose timing chain.

One issue came to mind on another members similar rebuild last year... Turned out it was one of the top idler mounting screws vibrating on the valve cover....

A stehoscope would be a good $5 investment... HB Tools...

My 900 rings like that and it is my front brake lever. I put my pinkie finger on it and it quits. I am scared I will break the bolt if I tighten it any more so I pinkie ride when it bothers me.

Old Man Rock wrote:

One issue came to mind on another members similar rebuild last year... Turned out it was one of the top idler mounting screws vibrating on the valve cover....

A stehoscope would be a good $5 investment... HB Tools...

Would the old screwdriver method also work here?

Screw driver, garden hose sure I guess...

Stethoscope is truly amazing on the volume/amplitude in sound pickup.... plus with the extensions you can get down in those tight little places other methods wouldn't...

Example... On my new build last summer, I had a squishing sound (avi clip provided to mentors) on WTF was it... Stumped everyone... Only occurred when running really hot (AZ heat in summer and due to dyo oil/no cooler)...
Plumm turned me onto the Stethoscope idea...

The sound seemed to be coming up top but with the scope, traced it all the way down to the oil pump! :S Even though the oil pressure was in spec the pump had a squishing sound... Was weird...

Anyhoot, e-bay, $20 pump no more sound... Life was good once again.... :laugh:

Either method would work... I think Plumm just uses the meatl in his head... Lays his head on the valve cover and the vibration oscillates & transfers into his ear canal.

Or was that his willy :blink: he was using, I forget now...

Kawickrice wrote:

My 900 rings like that and it is my front brake lever. I put my pinkie finger on it and it quits. I am scared I will break the bolt if I tighten it any more so I pinkie ride when it bothers me.

Happened on my 650 too. Also the gas cap lock tumbler will vibrate and make a similar noise.