What kind of sound do the valves make when they aren't adjusted right? When I have been traveling 85-90 MPH for 15-20 minutes at time I start hearing a fast buzzing sound. When I back off it stops but not immediately. Any ideas as to what it could be?
I have stock pipes on my C model. There's a certain frequency where the pipes produce a vibrating sound, similar to the sound a glass pack muffler makes at high revs when the engine is decelerating. Seems to be normal.
Also, the speedometer housing sometimes becomes loose from the tank and will buzz or vibrate. Mine was OK after tightening the allen bolts, some people have put O rings or rubber washers underneath the speedometer/gas cap housing to stop that noise. Next time you hear it, try pressing down firmly in the speedometer area and see if the noise stops.
High speeds also cause heat buildup in the engine and may be causing the fuel to ignite prematurely, that can cause the pistons to rattle. Also normal.
The valves would produce a rapid "clicking" sound, if too loose.
I just ajusted my valves and I can only hear a slight tapping noise at low speeds. I think i may have the exaust valve a little too loose. I'll check it out in a day or two. as for damage. I hope not!. I want to see what others say too.
This is a late post, but I had that same problem going about 80 and 85 mph on the highway. Had that same buzzing sound. I thought it was the valves also. But it was my Headlight. There is a mod for the headlight that will fix that. I know that is what it was on my VTX Retro 1300. Fixed that noise.