View Full Version : need help with diagnosing very strong vibration
hi, noticed today and friday when using the bike that its got a really deep distinct rumbley vibration coming up through the rider seat and can feel it through my knees on the tank.
It seems really bad at 3-4k revs, havent riden any harder as just in commuting traffic on work journeys. Its aways been quite vibey, but the past few days its really bad, and when I started it on choke, you could even hear the vibes coming up through the frame to the tank etc, so its doing it when stationary as well.
Ive had a quick look for anything loose, but nothing obvious, I had the forks out for new oil 2 weekends ago, but surely that would be causing this???
Oil level was 3/4 full, and changed oil and filter on saturday, old oil had only done about 2K since last oil change a year ago.
I know its a bit of a stab in the dark here, but maybe others have had this and can say, try this, or so and so is on its way out.
Thanks, Lee
Does it still do it at 4k revs when stationary in neutral or do you need to be moving to feel it?
not sure tam, will be going outside in a mo to see if there is anything loose, and will rev it up to answer your question....
DarrenSV650S
09-01-12, 06:44 PM
It's the CRANK! Welll I don't know that actually. But mine got very viby just before the crank gave up. But hopefully it's not that on yours :)
right..... just been outside, bike vibrates wether in gear or neutral, does it when stationary or when riding along. Reved it upto 5k, still done it.
Ive looked for loose engine mount bolts, losse exhaust, loose anything, couldnt find anything wrong. wondered if the frame was cracked, or headstock, cant see anything obvious.
It does have very slight cam chain rattle, but its had that for the 3 years Ive owned it. I did put my ear to the tank while it was running, but all you can hear is the engine running as normal, but amplified through the tank. Held my hand on either side of the engine while its running, and can feel it, but it revs up ok with no extra noises, just the feel of the excess vibration.
Im stumped???
It's the CRANK! Welll I don't know that actually. But mine got very viby just before the crank gave up. But hopefully it's not that on yours :)
im a little worried its the engine, as nothing external seems obvious.
maviczap
09-01-12, 06:51 PM
Hope its not something like a engine bearing on the way out
Owenski
09-01-12, 06:54 PM
Does the vibe keep proportion with the revs?
ie more revs more vibes?
If it happens when the bikes stationary then you can be certain the only moving part is the motor, both plugs firing?
would be just my luck, had to scrap my car due to engine fault, as it was uneconomic to get it fixed.
Does the vibe keep proportion with the revs?
ie more revs more vibes?
If it happens when the bikes stationary then you can be certain the only moving part is the motor, both plugs firing?
same strong vibe whatever the revs, first noticed it when starting it on choke friday, then again today, so 3K on its strong. both plugs are firing, when off choke when its warm it ticks over fairly quiet and got its even cycle of both cylinders as normal.
Did you see any thing in the oil.
Can you link it to the oil change ? The slight starveing of oil on a weak bearing might have done damage.
Get a screw driver rest it on the engine cases ear on tuther end to help pin point its oragin.
check the simple things first.
battery - is it good condition, well charged and the terminals tight?
spark plugs - how old are they and have you checked that the front one is not damp?
R/R - don't know much about them but worth getting the meter out and checking.
cables/connectors - could be a loose wire or dodgy connector.
fuel - water in the fuel tank.
Lee knows his stuff Billbo.
New battery an reg fitted in december. Im goin to have the tank and fairings off next as the vibe is coming from the middle of the bike.tried screwdriver on the casings and not sure if it's internal or external of the engine.3 of us having a prod round,all 3 bikers and the other 2 know their stuff.
Vibe isn't clutch related,no noises like knocking,metallic etc.im wondering if the engine bolt with the castle nut and sleeve has started to come loose,looks like the thread from the main bolt passes into a sleeve and then locked in.
Dont think oil change the issue as I first noticed it Friday morning,and didnt do.oil change until Saturday.oil level was fine,and only done 2k miles,but I do 2x 4 mileage journeys a day so doesn't get a decent run.
More hoping it's something shaking itself loose, but it's bloody comfy to ride at the mo,and if it is something rattling loose its multiplying the vibes further from it.
Lee knows his stuff Billbo.
not saying he doesn't but its sometimes nice to have a little nudge. the more you know the more you forget :-)
yorkie_chris
10-01-12, 07:51 PM
Worst case is big end, if it is that then a quick blip of the throttle makes a big KNOCK noise as the revs pick up.
Many other problems shut up as the revs are climbing like camchain ones, the acceleration controls the slack in chain.
not saying he doesn't but its sometimes nice to have a little nudge. the more you know the more you forget :-)
happy with any suggestions ;) just realised my earlier post via phone is a little contradictory :confused: it more uncomfy with vibes the faster I go!!:rolleyes:
speedy: did think that today, so going to get that done asap to rule that out. Its definately not knocking YC, and the cam chain rattle is only evident at tickover, so like you say, must be taking out the slack, revved it just over 6 to see if any worse the higher again, its more noticeable still.
When i get the carbs balanced i`ll get him to check over anything else,wondering if the airbox can come loose and that make it vibrate like that as its rattling along.
I myself would start with the basics, probably something simple!
Carb balance can cause rough running/vibration if its out.
Doesn't have to be worse case scenario
:-)
hoping to get carbs balanced this weekend.
really odd, but popped to the petrol station last night, about 1/2 mile away and the vibe had gone :confused:, filled up with fuel, rode home and it was back again :confused:
Took off the tank to have a good look under there this evening, nothing seems to have come loose,so next step is carbs.
Well.....seems my front sprocket is loose, well the large nut holding it on is, it can move a couple off mm back and forth on the thread.
Ive got a socket here big enough but have never touched a front sprocket before.
Looks like I`ll need to remove the assembly that the clutch cable goes into as its in the way. do I simply undo the 2 10mm bolts, slide that off and unclip the small tensioner spring to allow my socket to fit on the sprocket nut?
Thanks, Lee
http://www.ronayers.com/Fiche/TypeID/26/Type/CLUTCH/MakeID/2/Make/Suzuki/YearID/42/Year/2001/ModelID/6380/Model/SV650S/GroupID/263876/Group/CLUTCH
part 17 is the part that partly covers sprocket nut, do i just remove that, or not the way to go?
Urbanfireblade
15-01-12, 03:51 PM
I can't see it being the sprocket as it does it when stationary. Is the engine against the frame anywhere-transmits the engine vibes directly then. Also, if it didn't do it for a period of riding then i would rule out bearings, once they're on their way out they don't get any better, just worse.
Does the engine visibly vibrate excessively, yet run fine with no misfires etc? Hard trying to think what it could be if you say it didn't do it for a period riding to the petrol station, that says its intermittant, so not a balance weight thrown off crank or somewhere.
Urbanfireblade
15-01-12, 03:56 PM
I'd say it will be ok to unbolt, it looks simillar to my old 1200 bandit, but that component was attached to the engine cover so when you removed the cover that component came away with it.
DarrenSV650S
15-01-12, 04:36 PM
Lee just undo the two bolts on part 20
And be careful not to let the clutch mechanism unscrew itself or the ball bearings can fall out
maviczap
15-01-12, 04:41 PM
Lee just undo the two bolts on part 20
And be careful not to let the clutch mechanism unscrew itself or the ball bearings can fall out
As above and have a look to see why the security washer behind the nut isn't doing its job. Maybe a good idea to get a new one
done the nut up nice and tight now, the washer was at least holding the nut on, the nut had loosened off enough, but held in place by the washer.
Also checked the clutch and stator today, theyre both tight. no time to check carbs, but im not convinced its those, as Ive had them balanced in the past and totally different sort of vibration, this is more like something is slightly loose, but as yet i cant find it
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