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Have a 660 with tapping in top of motor, the cam lobes are scored/groved pretty bad, just wondering if this will cause the tap in the top of the motor i'm hearing. It still runs perfect and has no loss in power, I know the valves are adjusted to spec and timing chain is new and adjusted properly. Everything is tight on the top end also, as far as bolts and motor mounts.
 

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If the cam lobes are in bad shape it's going to start eating your rocker pads, likely already has. They are hard to get a hold of as they are not available by themselves from Yamaha as an OEM part.

Swap out the cam would be my first suggestion. If the cam and pads are worn then you can definitely get some extra noise from the top end.
 

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If the cam lobes are in bad shape it's going to start eating your rocker pads, likely already has. They are hard to get a hold of as they are not available by themselves from Yamaha as an OEM part.

Swap out the cam would be my first suggestion. If the cam and pads are worn then you can definitely get some extra noise from the top end.
If they are worn, I suggest you check why this may be happening, loss of oil pressure or low oil pressure would be my first suspicions...........
 

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Have a 660 with tapping in top of motor, the cam lobes are scored/groved pretty bad, just wondering if this will cause the tap in the top of the motor i'm hearing. It still runs perfect and has no loss in power, I know the valves are adjusted to spec and timing chain is new and adjusted properly. Everything is tight on the top end also, as far as bolts and motor mounts.
This is a symtom of something else going on. You have low oil presure and or contaminated oil being caused bya possible number of things. Cloged oil pickup screen, filter. Bad oil pump.ect. You may have scored the piston pin also. Check oil presure as per manuel. Change the oil and filter 3 times at 20 min intervals to help clean system. Do you have a worn original one way? Its a good sorce for contaminates. If you change the cam, check the cam journals for ware. The rocker arms should be rebuilt or replaced also. If you have low/no oil pressure, you will have to split the case for inspection and repairs. Good luck.
 

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You can get the rocker's seperatley can you?
 

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Discussion Starter #8
sorry, i meant to say where the cam rides on the head is scored pretty bad/grooved pretty bad, mainly the head. Also, how can you check oil pressure, all i've is where you can remove the screw at the back of the cam and verify oil comes out.
 

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sorry, i meant to say where the cam rides on the head is scored pretty bad/grooved pretty bad, mainly the head. Also, how can you check oil pressure, all i've is where you can remove the screw at the back of the cam and verify oil comes out.
That is where you can verify oil pressure also, if the head is scored in the area of the cam journals and the cam is loose in the head, you most likely will never get the proper oil pressure with that type of damage...........
 

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They're not in the microfiche, though I admit I have never called up a dealership and asked to buy them.
They are only listed as part of the complete head assembly. Some of the cam vendors may have some that are hardened and part of there packages. If anyone has a OEM part number for just the rocker arms, please pass it on.
 
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