Mainshaft Sounds Bag-o-Rocks in Neutral.

When in Neutral, with the clutch released, my tranny / or clutch sounds like a bag of rocks? Quiets right down when you pull the clutch in and it's spinning on the throwout bearing. Is this common to other owner's here (Its an early 2009 GRiSO 1200 8V) ?? Just gears rattling along their respective grooves when no load?Throwout bearing flapping about?

Thanks!

Sounds like poor throttle body balance exacerbating the idle hunting. When was your throttle body balance last checked and by whom?

Pete

I've noticed, what sounds similar to your description, only a couple of times. It was after coming back from a ride and parking to open the gate. While in neutral it would make a clatter but preloading the throw out bearing sorts it out. Not to worry unless it gets worse or annoying.

Pete Roper wrote:

Sounds like poor throttle body balance exacerbating the idle hunting. When was your throttle body balance last checked and by whom?

Pete

Last checked TB balance about 8 months ago. By me! This was with guidance provided by the little how-to guide you published a while back, Pete. Used a carb mate and @ 4000 RPM she is smooth... idle, not as good but not too bad.

The rattles are definitely emanating from the gear box. It is a constant and i just wanted to check in with the rest of the mofos here to see if this were a common experience. Was focussing on the mainshaft because that is what spins when in neutral, with the clutch out, right? Otherwise she shifts pretty good.


BTW: When you next in Seattle, Roper? Figure I owe you a steak and a beer just for that little guide about TB balancing, alone.

Cheers.

What map are you running and any mods to the bike in terms of pipes or airbox?

Pete

Pete Roper wrote:

What map are you running and any mods to the bike in terms of pipes or airbox?

Pete

Running Beetle Map "Griso24S-FU2-F3DC.2014.06.14"; QuatD Slip-on and BMC Filter. Airbox Cover is unmolested.

Thanks.

FreshEgg wrote:

When in Neutral, with the clutch released, my tranny / or clutch sounds like a bag of rocks? Quiets right down when you pull the clutch in and it's spinning on the throwout bearing. Is this common to other owner's here (Its an early 2009 GRiSO 1200 8V) ?? Just gears rattling along their respective grooves when no load?Throwout bearing flapping about?

Thanks!

I have a 2006 1100 and mine sounds exactly as you describe. It sounds to me like the gears are rattling in the box. The noises we are hearing are pretty close to noises I've regularly heard on Staffs or Hewland gearboxes used for FF/FC/FA cars in SCCA. Those gearboxes have dogrings but no syncros so when you release the clutch it spins spins a shaft in the gearbox but since no gear is selected (neutral) all the gears rattle. I know motorcycle boxes are different but the sound is pretty familiar...

It's actually pretty annoying but I do not not how to stop it.

I've listened to other motorcycles that do not do this but I do not know why. Perhaps the gear stacks are preloaded with disc springs?

Tim

With the 1100 you still have a face cam shock absorber on thei put shaft. Some of the early boxes had inadequate preload on the stacked Belville washers that provide the 'Spring' and so at idle the face cams are not preloaded and 'Knock'. It sounds terrible but the factory claims it does no harm. Early in the piece there was a 'Technical Update' that involved adding more spring shims to the shock absorber and it would be worth doing if you have the box apart sometime but on a nine year old bike it isn't something I'd do pre-emptively.

Pete

That makes a lot of sense Pete, thanks for the explanation. I'm not going to tear into it unless there is some other reason besides that annoying noise.