High Frequency vibration.

I've just started noticing a high frequency vibration at around 6-8000 rpm (70-80 mph) and I was wondering how to resolve it.

It comes through the bars, foot rests and through the seat and only seems to be there while moving. Not able to track anything down by just sitting on it and revving the engine.

So I'm thinking it may be chain, drive or possibly carbs needing balancing. Its done just short of 24K so was going to take it in for a service and wondered about asking for them to check out the tappets and balance the carbs at the same time.

I've checked the chain adjustment and the bike for other loose items but have not managed to reduce the vibration.

Has anyone any ideas suggestions for my next steps. :idea:

They will be much appreciated.

you havent lost a barend have you, or ballance weight's from you'r wheel's, look for the easy thing's first

engine mounts still nice and tight?? Oil level correct?

as furball says have the rear wheel /tyre balanced first off

I think it is normal to have a vibration around 7 000, however it isn't that bad. When mine started becoming more noticeable to the point my hands became numb I found the culprit was carb balancing.

I know this is a old thread but was the vibration problem ever solved I have got the same issue and can't find the effin thing
Cheers

Basically no. I've just got used to it. Now I don't think it's that bad. The vibration is still there but it only is noticeable when I press my boots into the footrests.

I checked all of the things. Mentioned in the posts but nothing was amiss. So it's been lived with.

I have this also, mine is going in next week but I think it will be Carb Balancing as it has been 7k since it was last done. I ruled out wheel balance as it does matter what gear i am in I can feel it at 6-7,000 revs.

I think I did read on another forum I could also be a bad spark plug, still boils down to engin not running smoothly.

Mind you, if I had a nice female pilly then I would always ride it a 6-7,000rpm.

John, the carbs shouldn't need balancing that quickly. Mine have never been done while I've had the bike (12k). My mechy said if the engine is running okay then your carbs should be fine.

Btw, you still off to Wee Mac?

Yes, the 'Cat has been known to be 'lady pillion friendly' around 7k

Then again, I may try putting original can back on and see what happens - mine has been cut down by about 4".

All straight 4 cylinder engines have a vibe at a specific rev, the rev depends on engine design and the main cause is crankshaft rock around the centre of the crankshaft. If the carbs are very slightly out of adjustment this rock will get worse. Have the carbs adjust so that the vac readings are all the same, not just to Yamaha specs. As for tappets mine never altered in 5 years, but it is worth having them checked just to know that they are ok. I check my carbs every 6 months and its always number 3 that is the first to go out of balance.

Wheel Balancing

Update:

My bike has been into the Mechies (BSD Performance) and the excessive vibration was caused by the Carbs being out. Also, it is only running on 3 cylinders when first starting up which looks to be a dodgy spark plug. Recommendation is that it needs a good service - oil/filter, sparks, air filter clean etc) with major points being lubed.

Good to hear, enjoy getting mucky with the service!

They also sold me an oil filter go £10. Is that cheap?

YZFJohn wrote:They also sold me an oil filter go £10. Is that cheap?

Depends, does it have any rare gems or gold leaf decoration?

Nope it's just black.