why is my gear change clunking

[jono]

well ready for painting and decals, I haven't decided on a color scheme yet I'm thinking black and blue with a pink pin stripe as it  originally had the pink pin stripe when it was produced Ive sorted the jetting thanks to advice from you guys and its pretty much going real good except the gear change is clunking if i concentrate and throttle off its silent with no clunk  but the moment im riding normally whether slow or open road speed it clunks whether shifting  up or down   ,Ive bled the clutch and its really good it doesn't lurch when i put it into first it does clunk though but doesn't move forward at all and it does not slip under acceleration  ,Ive checked the chain and its not too tight i even reset the suspension preload softer with the right sag  and it still clunks is this common for a 3xw model ? or have i set something up wrong I'm running Penrite MC-4ST Semi Synthetic Motorcycle Oil 10W-50 and im wondering if it could be the problem i have read online people claiming different oils can effect gear change

jono

[wainot-Phil]

Hi Johno , I would just check that the Clutch Slave is not leaking at all and also that the gear change linkage is adjusted so it is centered and the Gear Lever moves up and down easy both ways with the same effort ,Also check the Gear Change Lever is not hitting the Side Stand at all.

[red]

Jono,

There is a brass bushing in the clutch lever (not the lever pivot) that pushes the clutch rod into the master cylinder.  If worn, it can give you clutch dis-engagement problems, which may be what you have there.  Index #4 on the fiche:

http://www.adeptpowersports.com/oem-parts/1991-yamaha-fj1200b-front-master-cylinder-2-assembly.html

Last I checked, RPM has them, no need to buy the entire rebuild kit:

http://rpmracingca.com/proddetail.asp?prod=M%2FC%3AClutchLeverPivot

Clean and lube the bushing on some regular schedule, depending on riding times.  HTH.

[jono]

its not the clutch activating system im sure of that ,both cylinders are good and its bled good like i said if i change slowly and go through the motions carefully it changes silently most times, my problem is normal riding and shifting up without slowing right down  it clunks most times Ive checked the clutch lever bushes and there all good ,i realigned the gear  lever slightly and it 's maybe slightly better but its still clunking most shifts up or down i think i might change to a different oil here in NZ motul seems popular and someone suggested shell advance it seems most people are pretty happy with the standard FJ gearbox so ill see what happens with different oil and if that doesn't improve ill pull the clutch and look there

as always
thanks
jono

[ZOA NOM]

Is the chain adjusted too loosely?

[FJmonkey]

Do you have Yamaha clutch parts installed? I had a bad clunk as well, worse when cold. Turned out the friction plates were aftermarket. They were thinner to allow more friction plates (more friction surface). This concept failed. When I took the parts out I found some frictions worn down to the steel and some had zero wear (stuck all the time). I replaced with OEM parts, and while I had the cover off I installed the roller bearing shift kit from RPM. Shifting and clunking issues were much better.

[Pat Conlon]

Golden Spectro oil makes for a smooth gear change...

<running for cover>

[giantkiller]

Golden Spectro oil makes for a smooth gear change...

<running for cover>

Lol

[jono]

well Ive adjusted the chain slightly again  and a half turn on preload at rear it's all pretty well set as good as i think I can get it and it still clunks i don't really know what to  expect as to how it should shift maybe the more i ride the better I will get and its not so much the bike but the rider as my last daily ride was in  1999 on a fz750 which from memory didn't have this problem so my next step will be to change the oil I can get Spectro Oil L.SG425 Golden 4 Semi-Synthetic 20w50 in New Zealand for a good price so ill try it out and if that doesn't improve things ill open the clutch and see whats going on in there i like the sound of the roller bearing shift kit i might get one of those regardless

thanks guys

jono

[ZOA NOM]

I would suspect a worn chain/sprocket combo. The chain should flex about an inch along the bottom between the sprockets when properly adjusted. When in doubt, looser is better, to a point. If the teeth of the rear sprocket are worn enough, the chain can jump teeth, with a *clunk*.

[red]

Jono,

If the drive chain sprockets are worn, the chain can become both loose and tight, as you rotate the rear wheel (bike in Neutral, on the centerstand).    If the chain is adjusted when the wheel position makes it tight, then the chain may be too slack as the wheel rotates to the place where the sprocket is worn.  If your sprockets are worn, with a variable chain tension, then replace the chain sprockets as needed, whether there is a clunk or no clunk.

[jono]

nah its not the drive train-train guys at first I thought it was and checked it thoroughly and slightly loosened it to max spec and no difference I'm running a brand new 17T Front Sprocket- 39T Rear Sprocket - 110 Link RK Chain i also thought it might be the shock as it is a relatively new aftermarket hagon and the back wheel skipped on the slightest bump or twig etc so ive dialed that in as well because it was way to preloaded which makes for for a way better ride now, but the changing is still the same clunk . I'm going to get spectro Golden 4 Semi-Synthetic 20w50 next and see if that helps .
I'm dismantling my spare 1tx motor at the moment so im gunna see what the clutch is like in than its done a genuine 100 000km the bores are mint the guides are good so mabe the clutch will be good ill measure up every thing in the next day or so and see if its worth putting it  in my 3xw but hopefully the oil change will suffice

jono

[Old Rider]

Place the bike on the centerstand best is if you can do it so the bike is leaned over to the right .Then push the clutchlever a little in and use a velcroband or tape or similar to fixate it in that position and let it sit over night.

[jono]

done ill let you know in the morning

thanks

jono

[jono]

well i did as you  suggested Old Rider and after a couple of hours i went back and took the cover off the reservoir  and the fluid was all murky with who knows what, so anyway i left the lever  taped half closed and tilted slightly so the reservoir was raised higher than normal for the night and this morning reassembled every thing and went for a 35km ride and it still clunked but I think not as badly so im going to get some fluid which Ive just about run out of and thoroughly flush out the whole system again ,I thought I had "but obviously not  good enough" then ill do the same trick again, i presume that taping the lever open and leaving it over night allows any air in the system to rise to the top, am i right in taking the reservoir cap off when I do this

jono