How much vibration is too much?

[digdoctor]

My Fazer is smooth like a babe's bottom most of the time. But I was coming home from work on Friday and got on the highway, above 70 mph (approx 5500 rpm in 6th) there was an uncomfortable amount of vibration through the entire bike. If i sped up to 80, it smoothed out some, and I suspect if I kept speeding up, which I didn't, it would go away all together.

Anyone have any ideas whats going on here? I know that its a rocket, and vibrations are common in bikes of this type, I just want to make sure there is nothing incredibly wrong.

 

[lawlberg]

It's probably too much. A TB sync would probably help you out a fair amount, also cleaning up your spark plug caps might help, look at the thread "a cure for bad vibrations" http://www.600riders.com/forum/fz6-...ons-spark-plug-caps.html?highlight=vibrations

 

[FinalImpact]

You need to be able to discern the root cause.

Is it:
- tire/wheel balance }likely not as these get worse w/speed not better
- drive chain }possible, but usually worse with load...
- Engine }TB sync is not relevant above 5K, vibes up here are something else
- Ignition }vibe is constant even while parked, can be felt throughout entire range from idle to 8K but harder to distinguish....

How:
- At speed - coast with clutch in, removes power plant from the equation leaving tire, wheel, chain
- Parked - can you induce the same vibe with static rev's
- Does it do it while accelerating? Likely drive chain lube or alignment.
- brake rotors bent, shudders during braking

Start there and report back if something stands out.

 

[digdoctor]

Finally got the bike out in between the rain drops. Vibration is definitely engine based it vibrates parked with the clutch pulled in. I'm thinking it might be plugs. Any other suggestions?

 

[FIZZER6]

I also have a 2006 model so what worked for mine might be more valid than those with 2007-2009 models.

When I did the TB sync for the first time at about 12K miles it was night and day smoother at all RPMS, including the 5-6K "buzz-zone" at 7K+ rpms my bike is much smoother, it just stinks because 5-6K in 6th gear is perfect for most cruising speeds and also the most buzzy!

When the weather is warm I notice a very noticeable decrease in vibration if I switch to premium octane fuel (91-94). I believe that the ignition timing around 5-6K is just a hair too advanced and the higher octane fuel lets the fuel mixture ignite a millisecond later which really smooths out the vibrations. Run 1 tank of premium through your bike and see if you don't notice a difference. It's only a couple dollars more per tank full and your engine will run cleaner on premium as well as smoother, win/win. The spark plug caps are on my list as well but I haven't looked into that one yet.

 

[digdoctor]

Thanks mate! I'll give that a shot and I'll set an appt for a tb sync should it continue. Thanks again!

 

[andyfazer600]

I had some vibrations before the winter lay up last year. During that time I checked and adjusted the spark plug caps as mentioned in one of the previous posts with good results. Plus I carried out a throttle body sync last weekend and the engine pulls much smoother and stronger thoughout the entire rev range now, it didn't need adjusting much but has made a significant improvement.