Taffy,
I had a phone conversation with Dale, after I just bought my 03 FE 501E, to find out possible failure points. He mentioned that the cam chain tensioner on the 01-03 Bergs was the same as that on the old 2000 and down motor. With the engine changes, came the problem of the tensioner moving close to completely outward to properly tighten the chain on some new motors. Dale welded a button on the end of the tensioner shaft to lengthen it a bit thus remedying the situation. Without the button, chain would rapidly come loose and grind up things. Not sure if an 04/05 tensioner is longer so that it can be simply installed as an updated/improved part? Would sure like to know who makes the aftermarket manual tensioner mentioned earlier in this post.
dan
PS A friends 03 501 had the auxillary (counterbalancer) drive shaft bearings go south. He inspected things by pulling the clutch cover off and upon seeing the damage, parted the bike out on E Bay. Never split the cases, but I suspect Simon is correct that the balancer bearings got loose and completely took up the gear slack heavily loading the aux. shaft bearings. His bike was knocking for some time before the failure and was being raced/revved in expert MX. Still think the balacer is out of place on an MX bike. Also FWIW, since vertical vibration is much more perceived than horizontal, I think Dales 70% balance factor would be a plus and worth the dinero. (100% balance factor totally cancels vertical imbalance)
