I made a previous post concerning a knocking or tapping with the following symptoms:

1. Hearing tapping sound occasionally at start up and a tapping during clutch in while shifting to second gear.

2. At speeds of around 60 to 75 mph as I slightly decreased throttle I could induce a very audible clacking sound but only during a narrow bandwidth of throttle decrease.

I thought that the above was piston slap or rod bearing!

Well, every think in the engine measures with-in the Yamaha new tolerances with the exception of one bearing:

The generator shaft and case bearing measures approximately 3 thousands difference. I have looked in the manual but cant find what the measurement and tolerance is suppose to be but the generator case bearing shows a copper color and I would expect this bearing to be like all the others and have a dull colored babbit coating!?

I would not think that this 3 thousands difference in this bearing with not much load could cause this issue I am experiencing.

What a bummer if I have to replace a thousand dollar engine case because of one small bearing!

What do you think?

Rich

Mine clacks too. It's the nature of the beast.

what kind of oil you running change to a V-Twin syn 20-50 You will fine it will quite it down a lot

I think that's the area Yamaha describes as causing the knock at low engine speed start.

Used to be bearings could be re-babbited. You might check around. Might be difficult getting the bearing out without damage though.

Scott B.

Just get ya some loud pipes you'll never hear a thing.

A BAK helps too. they are fairly noisey or at least the K&N is.

im with Curt...my pipes blot out the engine noises..i worried at first but after hanging on this site for a while i realized the noises are normal...its a big engine under us thats cranking..

Ok, I am not pannict any more. After removing the stator shaft and noticing the bearing was copper collored I went into shock thinking I had to buy a new case for a thousand all because of one bearing!

I have looked all through the yamaha and hanes manual and can not find any reference to what the deminsions are for the stator shaft and bearing. I measure a difference of .003 and could not imagine that this was enough to cause the issue.

I noticed that in the hanes manual in two different location they refer to bearing in question as a bushing! Maybe this explains why there is not any babbit and the surface of the bushing looks perfect and is not out of round.

Rich

I had the same problem....Get Loud Pipes!!

Yamaha posted information about this and in short, they say that becuase the big bore of the Road Star 1600/1700 and it not being water cooled which would muffler the sound, it is a normal sound.

We it stops clacking, then you have problems.

Mark