whirring noise ???

ok, so my f-head had developed a whirring noise that is just weird. It goes away or reduces greatly as you get going and the noise changes in pitch in relation to rpm. i thought it was sterter pintle hanging up but now i'm worried about spun bearing.. there is no associated rod knock though... other that the noise the motor runs fantastic... any clues?

 

fiber timing gear having issues?

 

generator/alternator?

 

I am not having any timing issues.. power is good at all rpm's but i may have the oil passage to the gear blocked I supppose

 

Water pump bearing? (or alternator, as eti said.)

Use a stethoscope, or a stick to your ear and you can precisely localize the source of such noises.

!Don't hit any moving parts while doing it!

 

You can use a long screwdriver as a stethoscope. Handle against ear, tip against part you are checking. A regular mechanic's stethoscope is better but this works in a pinch.

 

Remove the fan / charging system belt, start & run the engine, listen for the noise...or absence of it.

 

I would try OzFin's idea first.

 

That is where I would start also.

 

will try soon.. i will update when I figure this thing out

 

O.K. I am an idiot. alternator bearing. thanks for the help all

 

Glad you figured it out.
Better an external issue and not an internal engine problem.,
Oz