Posted by Richard fssnoc#(Ks) on June 14, 2003 at 20:19:27:
All - I have a problem that I need some of your expert advice on. I've fixed it for the second time but I don't know what's causing it to happen. Let me explain, on Wednesday, I went on the weekly fssnoc lunch ride 171 miles round trip. No problem going. but, coming back my bike went into its 60mph top end mode similar to when I first got the bike. Regardless of how much throttle I employed, 60 was the maximum speed other than down hill. Last nite, I jacked it up on my new fathers day gift a brand new craftsman cycle lift (just had to add that), tore into it again and lo and behold, the same problem again, an extremely black carb slide. Tehhnically I guess it's really a vacuum piston, but you know what i'm referring to. The first time I fixed it I just sprayed it down good with carb cleaner, wiped it down good and put it back together. This time, I went the extra mile and literally scraped off all the black carbon/gum/enamel/whatever off took '0000' steel wool and polished it and put it back together. Wala - it's once again back to its old self and more. But -- what in the world is causing this black buildup. This is twice now in just a smidgin over 6000 miles. Ideas guys? Has any one else had this trouble? What might this be a sign of that is wrong?