Hey guys, New to the board. I have a 1990 Paso cast rotors same shudder issues. Also had this on a 1986 FJ1200 it also had cast rotors but they were vented like a cars rotor. I started to feel the shudder/pulse on it after 70K miles or so and on inspection found the surface was worn down past the usable surface. I has small holes showing up in the braking surface, porosities in the casting. Replaced the rotors with some good salvage ones and it went away. I need to look close at the Paso rotors to see if I have the same issue. Replacing these are bit more expensive than the Yamaha but I'll take the Paso over the FJ any day.

I tightened the steering head more than I like but the shudder has gone. Next step is replace the bearings and torque correctly. I would guess the problem is a dud bearing / s.

I suppose 17 years is good life span for a steering head bearing. I probably should have changed it when I noticed the wheel bearings were past their prime.

Thanks for the information along the way.

A lot of water has gone over the dam since I posted that comment. I was able to score a correct tire for the rear at last summer's VMD swap meet at Mid Ohio (although it must be five years old), but my source for the front couldn't deliver. As a result, I had to fit a 120/80. So far, it seems to handle okay, although I haven't put many challenging miles on, but it doesn't look right. Also, I had to reposition the front fender up some to clear the new profile.

Sorry, but that's the situation. I guess we're not making any progress on a new source, not even Coker or someone like them. For the long term, we'd better consider 17 inch wheels or mothballs.