Well, last friday night I picked up the Mallory rebuild kit for the fuel regulator and installed it. The very !st thing I noticed was the replacement diaphragm (sp?) was 2 layer of rubber rather than the original single layer! Gee, could it be that Mallory found out there was a problem with the original diaphragm "relaxing" and causing the pressure oscillation? So, I spent the 5 minutes needed to remove the regulator & replace the diaphragm.......and turned on the pump. Reset the pressure and it was steady, no oscillation at all. $20.00 fix. The rebuild kit is not listed in the parts books by Summit or others (#3516), so I had to spend two days getting ahold of Mallory, & then order the part. At least the fix was easy in the end.