Engine Noise

[VA Rider]

Hello , I have read some of the blogs on engine noise and viewed the You Tube Videos. The noise I am getting is in the range of 3000- 4000 rpm it appears to be when not under load. The noise is a loud rattle from the engine but also changed harmonics when cruising steady. The bike runs great no issues just this noise driving me crazy. The noise is there all the time but varies intensity . Does anyone have any ideas? Note the oil comes out clean on changes.. Thank You Chris :music3:

 

[dan filipi]

What work have you done on the engine?
Often a carb imbalance will cause a knock as well as ignition issues.

 

[slabghost]

Have the carbs been synchronized or valves set? Has the noise been there since you got it or has it just started? What work have you done on it recently?

 

[joedrum]

wrist pin on the piston ...im sure ...the noise is there ...and wont go away....and will go forever ...it would be motor break down to fix that ....could be stator bolt loose rattleing ...use a scope or dowel rod and place on motor to find where the moise is coming from and post back

 

[VA Rider]

The noise appears to be up front, I have put 2000 miles since the bike was put back on the road. The speedo is showing 76k miles on it . not sure if accurate. The carbs have been rebuilt and not synchronized nor have i checked valve lash.

 

[joedrum]

might want to check the cam pullies under the timing belt covers they can make noisr when loose be great if that was it ...you sould be able to hear witch side and dam where with dowel rod ...if its a wrist pin you will hear it right on the cylinder that has it ...loudest there than the head...if its pully the timingcover willl be loudest if its valve adjustment it will be in valve cover the loudest

 

[mcgovern61]

The noise appears to be up front, I have put 2000 miles since the bike was put back on the road. The speedo is showing 76k miles on it . not sure if accurate. The carbs have been rebuilt and not synchronized nor have i checked valve lash.

Synchronizing alone (correctly) can make a world of difference. Valve lash is required maintenance and should be done ASAP. Noises while riding in the upper RPM range can be any number of things. Harmonic changes could be as easy as a bad exhaust gasket that shows up at the highest temps. Narrow down the noise type and location and we can help!

You mentioned looking at the videos....did any one video mimmick your noise remotely?

 

[VA Rider]

I am going to check the pulleys as well as catch up on the other maint issues. I took it out for a ride today to narrow the field and noticed that the noise is constant at that rpm range and does not increase in frequency with the rpm sounds like a drum beat that speeds up and slows down in tempo but not at the same rate as the rpm . weird but thx for help . making progress.... oh most important hope everyone is well and be safe riding..

 

[VA Rider]

I think I found the noise with help , Thank You all !!! The timing belts are worn and loose also the tensioners , the bearings are worn and sloppy. I will replace all and update. Thank You for the help.

 

[joedrum]

great this is good news it wasnt in the lower end of the motor ....got to like that.... :clapping: :mrgreen:

 

[AApple]

Belt flop? It's good you caught that in time, before the belts gave way.... :clapping: