a little rough or buzz at 4250-4400 rpm

[DioTiAma]

Good morning Mike. My scooter is NOT the one on the signature! Is the one on the profile picture. The speed at that revs is ~ 55km/h (depends on the surface of the road, rollers & belt condition anyway).

[beegmouse]

It's about 30mph

I also use Michelin City Grip 150/70-13 no rubbing.

I'll try the O-rings next time I have the cover off.

[kar120c]

I too have this exact issue, easy to hear using thrust smootly.
Someone told me it is caused by a the clutch contrast spring but I have not yet tested

[gn2]

Could be loose numberplate, take the plate off and put strong double sided tape on the lower stub.
You'll see what I mean when you take the plate off.

[beegmouse]

The number plate isn't the root cause.

I added a bolt to the number plate, and tried it without the number plate, the resonance is still there.

[kar120c]

Any solution? what Honda Service says about it?

[Kompact]

3600 kms on mine and now it is buzzing a lot as well around 4000-5000 rpm. Was smooth as butter up until recently.

[DioTiAma]

Good morning. I've replaced the rear tire (second time) although with a wider one Dunlop ScootSmart 150/70 - 13 M/C 64S again. It was balanced with an OEM weight 30gr balance (42706-MER-D00). 24000km service done! Everything was dissembled, cleaned, greased and then assembled again. Vibration is still there. Less though... My mechanic advised me that there is a great chance the vibration is being produced by the wider rear tire. Let's hope is not going to get worse and in 15000km that i'll need to change it again, i will find (eventually) the right size (Dunlop ScootSmart 140/70 - 13 M/C 61P).

[beegmouse]

It's not the tyre.

I've had three different tyres on mine, The current one is oversize and It's never made any difference to the buzz.

I think the only way to diagnose it will be to stick it on a rolling road at 30mph.

[beegmouse]

Spoke to a dealer at the weekend. He had a few returned because of this issue. He said reseating the body panels and adding self adhesive rubber between panels sorted it.

[01K03]

Hi Folks
I have a 2015 Forza here in Australia that has a similar vibration, mostly when I roll off the throttle. When your accelerating no sign of it. I only noticed this after about 500k and mentioned it to my Dealer's Service people at the 1000k service, I quote "took it for a ride mate and it's all good" not a lot of scooters here in Brisbane so I suspect they don't know what their talking about. I suspected vibration from the drive belt as the drive comes off but since it's only just done 2000k I haven't got round to it yet. A job for the future. Had normal bikes all my life but think I've had more fun on the Forza than all of them put together.......really interesting forum people, great stuff...thanks

[kar120c]

an update:
now at 3700 km the buzz/vibration disappeared.suddendly

[beegmouse]

Do you know what fell off?

[beegmouse]

So a little progress last weekend.

Disassembled the transmission because of a bad bearing.
Wheel off, case off, clutch off, belt off, variator off, saddle off, topcase off, Rear panels off, bucket off.
Ran the engine.

Still has the buzz, but not as noticable.

Putting things back on one part at a time. The biggest single difference was made by the black plastic panel which covers the transmission.
The one Honda use to cover the fact their engine casing is untreated, un painted and rots away in a disgusting fashion.

I scrubbed and painted the transmission case and didn't put the plastic back on. Sound is halved but not gone.

I think my engine just shakes at that rpm and the plastics amplify it.

[gn2]

the black plastic panel which covers the transmission.
The one Honda use to cover the fact their engine casing is untreated, un painted and rots away in a disgusting fashion.

I think its a heat shield.

[beegmouse]

how the hell do you extract item 22 from the driven face.

[DioTiAma]

Valve adjustment maybe...? I haven't done it and i probably won't. Half of the scooter needs to be disassembled. Like in fuel pump change... or LIFT-O-MAT Gas Spring Strut change! Or maybe i will in the next service@48.000km... if i still own this scooter!

[Cerno]

I have an 2014 nss300a. Has about 10,000 miles on it. Best thing ever, but i'm getting a rough vibration around 3000-3500 rpm. The whole bike rides really rough then. Any ideas?

edit: i should add after 4000 rpm it smooths out like new, but the lower rpm feel different, rough.

edit 2: this always happens between about 10 mph and 30 mph.

[aguim]

I have an 2014 nss300a. Has about 10,000 miles on it. Best thing ever, but i'm getting a rough vibration around 3000-3500 rpm. The whole bike rides really rough then. Any ideas?

edit: i should add after 4000 rpm it smooths out like new, but the lower rpm feel different, rough.

edit 2: this always happens between about 10 mph and 30 mph.

Try this : 2.75/3.00 tube sections, slid over the shocks' springs.

[aguim]

Update (now that I think of it):

Like somebody else has already mentioned, that 'rough buzz' mysteriously diasappeared with
a passenger on. Also was less evident (on mine) with the spring pre-load adjusters set @ MAX.
Very good indications that the 'buzz' had something to do with the shock springs themselves.

As soon as I slid the rubber tubes over them, bingo, they quieted down.