As I've posted about here asking for help several times over the past 9 months, my 2004 VN750 had persistent vibration problems. I got it with only 555 miles on it, from Owner #2, who had only put about 100 miles on the bike since getting it from Owner #1 a year or two before that.
Having also had (and still having) a 1994 VN750, I soon sensed the vibration was not a carb cleaning, carb syncing, frame bolt tightening or "needs new tires" type of issue. This is because I took it to not one but TWO Kawasaki dealership in my area to try to diagnose the problem, and that's what they pushed on me. I did need the carbs cleaned after 3 years of mostly sitting in a garage, and a few bolts were definitely loose (which I could tell myself, and tightened myself). And the tires, well, 6 year old stock tires could stand to be swapped out in any case, to avoid issues of dry rot. But still, my keys rattled and my hands and feet tingled any time I revved to 4K and beyond, sometimes as low as 3500 RPM. After I mentioned it didn't seem to help much, they more or less said, "well, some bikes just vibrate more than others". Right. Like I don't have a bike that's the same model but TEN years older and that much smoother to compare it to?
Finally I found an independent motorcycle mechanic (Manuel at Speed Motorcycles on East 95th St. in Manhattan) who's been in business for over 20 years, and did the job right. Not only were his labor rates the most reasonable, he also worked the quickest: I left my bike on Wednesday and got it back on Monday, whereas both dealerships took over a week to not solve my problem! He even took photos along the way to document his work, and explained to me what he had to to do!
Unfortunately he had to pull out the engine to get at the balancer (8+ hours of labor), and fix a few things that had broken on my bike due to the excessive vibration (weld a crack in the muffler and epoxy a crack in the fuel tank that was leaking fuel slightly - I had done this myself also, but missed a spot).
He told me from the looks of it, the balancer was installed wrong from the factory. Just great. So owner #1, who put all of 450 miles on it or so and who maybe gave up riding due to the vibration, could have had this fixed under warranty, but no, I get to shell out the C-notes 6 years down the line.
Anyway, it all cost me mucho dinero
, but my bike is nice and smooth now, and hey, look at some of the pics he took!
(I'm not 100% sure about what he was showing me, I'll have to hit the Service Manual at some point to try to follow along with the notes I wrote down mentally, so if any of you have corrections as to what I'm saying or describing, just reply and I'll be grateful for the education.)
My bike getting stripped down:
The frame, now sans engine:
The engine pulled out and being disassembled to get at the balancer:
And here's the problem with the balancer. The white marking pointed to by the screwdriver should line up with the white marking on the balancer about 60 degrees to the right:
The same flaw, a bit closer up and from a different angle:
This shot seems to be from the other side of the bike, and it looks like the same problem:
And here's a shot of it with the parts lined up correctly: