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Discussion Starter · #1 ·
Hi all
I guess the title says alot. My 02 with 47000 miles on it (1 valve job at 20k) has a very bad vibration in the motor above 5k rpm. The first shop tuned the carbs and scyncd them. Then said it was running great with no problems. The second shop said the carbs were out of whack re adjusted re synced checked the valves, motor mounting and ignition coils and told me it was better than when I got there and there and they could not find anything wrong also.

I undersand the bike has a normal bit of vibration but over the last month it is getting very bad. I'm very mechanical so I'm going to start in on it myself anybody have any ideas what to check?

Thanks in advance
 

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maybe check the cct? you might be getting some slop in the cc... really cant tell you much from what you wrote. Hope its not something in the bottom end, for your wallet's sake.
 

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Discussion Starter · #4 ·
I'd guess on the worst case scenario which would be something in the bottom end on the motor.

Does it sound like it's idling on all 4 cylinders?

How bad is it? Is it a death rattle or a vibration? Does it increase with RPM?
At idle it sems to have a miss. It's just uncomfortable. Mostly concerned about damaging the motor it's not bone shaking It does not really increase a noticeable amount after about 5k it'd just there although when I go to lunch I will try to notice
 

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ok just checked while at lunch the vibration does increase with the revs
The fact that it increases with the revs isn't good.

assuming the shop that looked at it is clueless, you think you have a cylinder misfiring what's it sound like when it's running? A dead ylnder will make it sound like a subaru with an exhaust on it. One cylinder will be running colder than the rest. Spraying some water on the hot exhaust pipes will let you know if one is cold or not etc..

Otherwise, it's something that rotates in the engine like a rod bearing or a main bearing etc.. Maybe even a counterweight or balancing issue.. Maybe you'll get luckt and is only a problem like a bent clutch basket or something.. The key to narrowing this down is once again gonna come down to sounds.. Is it making abnormal noises other than bolts rattling?

my buddies gpr damper lost a mount screw and his bike virbrates like something fierce over 8k
 

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If running a PC, try running a different map and listen to the change. Also do a sync on the TBs yerself to check what the shops have done. Ive noticed some of these "certified" shops dont know jack at times.
 

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If running a PC, try running a different map and listen to the change. Also do a sync on the TBs yerself to check what the shops have done. Ive noticed some of these "certified" shops dont know jack at times.
+1 to some places not knowing their head from their asses. This is a carb'd bike so there is no maps, etc. But syncing the carbs makes a world of difference. It most likely wouldn't cause or help with vibration like this tho.

OP, what kinda shops did you bring it to?
 

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synchronizing the carbs/throttle bodies only helps with idle issues. there is no power gains, no engine performance improvement, no fixing running funny issues etc etc.
it only stabilizes the idle.


where are you feeling these vibrations (grips pegs etc)? are they a high frequency vibrations?
or does the whole bike shake like a harley?

a lot of times guys like to remove the stock bar ends in favor of sliders or aftermarket ones but fail to realize the stock bar ends are weighted to counter vibrations in the bars. then they are left with numb hands.
 

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sounds like its doing it in neutral, right?

I'm thinking its gonna be something in the bottom end, the clutch, or the cams. (never had a R6 apart... is it cam or cams? :) )

Anyhow, if its doing it in neutral, pull in the clutch and put it in gear.... this will stop the clutch center from rotating. The basket will still rotate but it might be enough to feel a change.
Does this make it better? Worse? or stay the same?

with those kind of miles depending on how it was taken care of, it might be time for an overhaul. I cant believe these shops didnt even peek into the motor (or did they?)

Unfortunately its gonna be pretty hard to figure out without tearing it down, but its not a bad idea to see if a cylinder is running cooler as well.
 

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Discussion Starter · #11 ·
The fact that it increases with the revs isn't good.

you think you have a cylinder misfiring what's it sound like when it's running? A dead ylnder will make it sound like a subaru with an exhaust on it. One cylinder will be running colder than the rest. Spraying some water on the hot exhaust pipes will let you know if one is cold or not etc..
i tried spraying the manifold with water they seem to be pretty even. as far as the soudn it sounds nice and smooth but every 2 seconds or so for a split second it sounds like it misses or lobes then continues to idle nice and smooth.
 
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