Guide sprocket grinding

[mikefromgeorgia]

I have a Shimano Sora, 8-speed, GS for triple rear derailleur and a Shimano CS-HG50-8, 8-speed, 12/25 freewheel. The problem is that the guide sprocket grinds on all rear sprockets regardless of front sprocket position. I have adjusted the B-tension screw to almost every possible point without any improvement what so ever. I have already checked the high and low limits as well as the barrel adjustments on the rear derailleur to rule out any other cause for the noise (grinding).

Please help me....I need to ride :-(

Thanks!!

 

[mikefromgeorgia]

Another 2hrs blown on this pathetic little bike.

It's a Fuji...just to save ne1 the headache that might be considering 1 of these little nuggets of joy.

Any ideas, I'm up for it.