The dreaded vibes!

[mark g]

Hi Guys,


read all the recent threads on reducing vibration on the gen 1 thou, I guess mine is no different to others making it's presence felt between 3.5 and 5k, the right hand handlebar grip is noticeably worse than the left, and my lad assures me the exhaust side rear footrest is very bad.


I've undone all the engine mountain bolts, started the engine up the re-torqued the bolts back up but what I did notice is how close the exhaust downpipes are to the engine sump......practically touching just where the exup value is! is this normal? surely if the exhaust is touching the engine that would be the cause of the vibes on the rear footrest??

[Tmation]

There is a bracket on the collector box/exup area that bolts to the bike (left hand side as you sit on it i think) this is known to snap causing vibrations.


If that is fine then balance the carbs.

[AyJay]

Ivanising it will make it smoother in that rev range. It's point #1 here:


http://www.cartestsoftware.com/fz1/jetki...ation.html

[mark g]

cheers guys, will check the bracket tomorrow[size=78%] and I plan to Ivanise it very soon[/size] :lol

[PieEater]

As Tmation says balancing the carbs will help. I do mine once a year and am always surprised at how much difference a small amount of adjustment makes to the level of vibrations coming through the bars.

[mark g]

Cheers pieater, I'll get myself some vacuum gauges and balance the carbs..... I appreciate 4 cylinder bikes will have some high frequency vibes but I still think the exhaust is too close to the sump  .

[shrekster]

This is the main reason I sold my last fazer, I tried everything but could never cure it. I bought another a couple of years ago and it has the smoothest engine of the 3 I've had, unfortunately it has the clunkiest gearbox. It seems that you can get a good one or a not so good one.
Jim.

[mark g]

slackened off all the engine mounting bolts started the bike up as recommended then re-torqued all the bolts back up and I think it's got worse  :'( I did notice when I undid the last bolt the engine did noticeably drop so to speak so I'll undo them again and put jack under the lump before tightening them up. I'll look at balancing the carbs this weekend

[taylor]

mine is the same it shakes like bill haley, when I get home the wife is waiting because my knob is like a rampant rabbit,.

[AyJay]

mine is the same it shakes like bill haley, when I get home the wife is waiting because my knob is like a rampant rabbit,.

ROFL!

[mark g]

LOL Guys :rollin  as been mentioned earlier the rear mounting bracket on the down pipes is fooked, going to kill two jobs in one go now as all the feckin EXUP valve bolts are fooked too :'(  my mate runs and engineering firm so I'm going to get him to weld a new beefier bracket on and drill out and re tap the EXUP bolts and then I'll get chance to use my newly purchase Vacuum dial gauges to set the carbs up :-).
The rear mounting bracket captive nut proved to be a nightmare as it kept spinning around so a dab of weld sorted that out, the new bracket will just have a std nut and bolt for easy access and replacement

[mark g]

Managed to get a few pics of the fooked bracket etc

[mark g]

another

[mark g]

exup bolts

[mark g]

one more

[mark g]

Just an update, had the bracket welded back up and all the snapped bolts sorted out, EXUP valve is all greased up and guess what, the vibes have all but gone  :lol  I will still balance the carbs up just as a matter of course but for my bike at least it looks like the vibes were down to the snapped bracket.