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bad engine balancer caused vibration - fixed - now with pics!

12K views 12 replies 11 participants last post by  Knifemaker 
#1 ·
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. :doh:

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:

 
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#2 ·
Well, again I am happy for you.
But I think you should have just posted this in the thread you already started about this here:
http://www.vn750.com/forum/showthread.php?t=13605



Just say'n .....


Anyway, hey look...your balancers are not lined up correctly !! What a asphuk for you considering the guy was more than likely right about the factory screwing it up in the first place.

Perhaps you can try sending the photos to Kawasaki and explaining the situation....they may not pay for it but they might at least send you a gift certificate or something.

I do know of one instance where a Honda dealer made good on a bike that was several years out of warrenty when it was discovered they did not install spoke guards in the front wheel.

Couldn't hurt to try.


KM
 
#3 ·
Couldn't hurt to try.
KM
I agree with KM. The fault lies at Kawasaki's feet, and they should take responsibility, INCLUDING the $ you paid their incompetent dealerships to misdiagnose the problem.
 
#5 ·
I agree Kawasaki should pay for it, but they won't, just like they won't pay for all the damage caused by them not having lubricated the driveshaft splines during assembly. Fortunately you got it fixed before it did serious damage to the case.

I suspect a number of Vulcan 750s were built with this problem. While both of mine have been really smooth, I have read several reviews on it that complained of vibration. It puzzles me why Kawasaki chose this route when designing the engine, rather than go with offset crankpins the way most every other Japanese manufacturer did.

I totally agree with the dealer thing, I won't go near one. I get all my oem parts online. Jerry.
 
#6 ·
I started a new thread mainly because I cut-and-paste a new-thread posting in another M/C message board that's for riders in my local (NYC) area, to give props to this guy who I feel did an outstanding job at a reasonable price, and is in a more convenient location with more convenient hours to boot. If there's a mod who wants to merge the threads together on this board that's fine.

I mainly wanted to document for the group, with the pictures the mechanic supplied, what the balancers (should) look like. While trying to figure the problem out myself over the past 9 months or so, I've found old postings here on vn750.com from other people describing the same issue: "my keys dance", "my hands/feet tingle after riding", "my mirrors shake", etc. Often the first things people suggested were what the dealer mechs, and also the Clymer and Kawasaki's own Service Manual, suggest to check out first: carb syncing, frame bolts, tire wear, rubber mounts that have cracked or dry rotted, etc. One of them (I think the SM) does mention the balancers being a potential issue but gives it as the last option, "as this will require pulling the engine".

So if it comes to that for anyone else looking at a vibration problem that won't go away, and feel inclined to try an engine pull job themselves, I hope these pics will be some small way for me to give back to this board's user community for putting up with my silly newbie questions and occasional rants :)

In the end I don't blame the shop mechs for not suggesting the balancers as an issue; everything they suggested as a factor are the standard ones to check out first, and I'm sure they'd prefer to fill their paid-by-the-clock time with 8-10 hours of oil changes, brake fluid bleeds, carb cleanings and tire installations that they can cruise on autopilot for instead of an 8-10 hour serious engine pull job that they'd have to, like, actually concentrate on. What annoys me is that they could at least have admitted "we cleaned the carbs / put on new tires, which you needed in any case, but you still have the vibration problem and it's gonna be a big job to take this further", as opposed to acting like "well now it seems pretty normal to me".
 
#7 ·
Hey man thanks for documenting all this. Great info and pics. Too bad you had to go thru all the crap but it must sing now after things got put right. With each mile click on the od, the pain of the green that left the wallet dims more and more ;). Take care.
 
#9 ·
Hi guys (and girls). Not sure if this is correct place to put this but here goes anyway. I'm after some advice. I had the vibration issues talked about above so I've just pulled the engine out replaced the dampers and put it all back and still the same blasted problem so obviously not dampers. The bike has 11000 miles but only had it a year so don't know any history. Any advice on what to try next would be much appreciated before I throw myself off a cliff. ;)
 
#11 ·
I have a 07 Vulcan 900 with very similar issues. Vibrates like crazy on initial start and idles higher than before. This happened after I got it back from a mechanic to replace all three interior bearings. Now once I get on the bike and ride between 55-75 MPH it vibrates so bad my hands, feet, and butt go numb. If I pull in the clutch, it’s fine. Rode smooth before but now I don’t even want to ride it. Want to get this fixed and back on the road. Think it’s the same issue?
 
#12 ·
Hard to say, don't reckon most of us around here know too much about those Vulcan 900's. You'll have to check parts diagrams or VN900 forums to see if an internal balancer is a common failure point. My buddy has a 900 Classic and it's smooth as silk, so yeah I'd reckon there's something not right with yours, but unfortunately not a whole lot of help is likely to be had here...
 
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