Clunky gearbox

My x has done almost 14000 miles. Had a full dealer service at 12k, & all seemed ok. I had new chain & sprockets installed around 1200 miles ago - didn't make a difference to gear changing, but bike seems to run faster (less friction???). However, over the last 1000 or so miles, my gearbox has become decidedly clunky. Clutch seems fine, changing up is ok if I'm super smooth, but down changes are really clunky. I don't thrash her too bad, but do ride quite hard. Oil is Castrol semi-synth. Any thoughts???

Try changing the oil.

Check chain tension, it does impact the "clunkiness" on my R. I also agree to try changing oil.

+1 on the oil

Just for your information I will never again put Castrol oil in any of my bikes......

My Yamaha dealer nearby uses or used Shell oil at services.

Put it into my first yamaha R6. clutch started to slip and gearbox felt clunky.... Changed to recomended Shell oil, no problems.

Had a yamaha RD 250 for a while and mounted a new clutch. Bought Castol because it was easy to get at that time..... clutch started slipping....
Took the oil out and cleaned the disks and everything and then put in new shell oil or if it was some other brand Spectre Golden or something. No problem with clutch after that.

In my Yamaha XT660X i just used shell oil and didnt feel any problems with clutch/ gearbox. Rode the bike for about 6000 Km.

Just bad luck or?

YZEtc wrote:

Try changing the oil.

After only 2000 miles since service/oil + filter??? That seems waaaay too soon.... Could it really be the Castrol??

Yes. I won't use Castrol anymore either. I ran it in my quad and it slipped bad, not to mention heavy shifting. I wouldn't dare put it in my bike. I use Rotella.

Personally, I don't think 2,000 miles is waaaaayy to soon.
Change it and see if it's better, or forever wonder about it. ;)

Mines been clunky on down shifts, especially going from 3 -> 2, and 2 -> 1, since it rolled off the dealer floor. Are you sure you aren't just paying more attention to it now?

oic0 wrote:

Mines been clunky on down shifts, especially going from 3 -> 2, and 2 -> 1, since it rolled off the dealer floor. Are you sure you aren't just paying more attention to it now?

I think that may be some of the problem - perhaps its not THAT bad, but I'm sure it has been better in the past. I guess I'm worried that I might be damaging something
I really don't want to hurt her, but I heard these motors were bullet proof.... It would REALLY surprise me if: 1) Oil is cooked after 1000 or even 3000 miles - I don't do track days, & I don't thrash her to death. 2) Castrol is really THAT bad - after all, they've been around for years & are a 'known' brand. Its also weird that the clutch feels fine (no slipping/weird noises), & up-shifts are basically OK.
Anyway, if I change the oil, which this time I'll do myself , can somebody tell me the correct size crush washer I need for the drain plug - presumably a standard copper thing???

12mm diameter washer.

YZEtc wrote:

12mm diameter washer.

Presumably inside diameter = 12mm & material = copper??? Sorry to sound a bit dumb!!

It's sized to fit an M12 thread, so it will probably be closer to 12.5-13mm. Copper or aluminum. The one on mine is currently aluminum. I don't replace them unless I lose it in the oil bucket...

Arkmage wrote:

It's sized to fit an M12 thread, so it will probably be closer to 12.5-13mm. Copper or aluminum. The one on mine is currently aluminum. I don't replace them unless I lose it in the oil bucket...

Thanks to one & all - amazing how quickly you get information around here!!!
Just (another) question though: how many oil changes is a crush washer likely to survive? Is 20 Nm torque suitable for both copper & alu washers? After a few oil changes, won't the washer become compressed & therefore require more torque to seal it??
Ooops - that was actually 3 questions.....

You'll find that alot of people never change out the washer. The other folks change it out every time. Go figure... I change mine about every other time. Just find them somewhere cheap and buy 10 or so.

Slightly off topic,... When I bought my used WRX the oil had been changed once by a dealer. I couldn't get the oil drain bolt off with my longest rachet. Had to use a breaker bar and push it with my foot. Kind of pissed me off... Knuckleheads.

mash,

Go a bit easy when you tighten the bolt and afterward make sure it and the area around it is clean and dry. Keep an eye on it for a couple of days to check for leaks, you can always tighten it a little more if you need to. You'll soon get a feel for these things. Post back and let us know how this goes.

Sarah

Cool. I found some copper washers in our workshop suitable for M12 bolt: I/D = 12.5 mm, O/D = 18 mm, thickness = 1.5mm. I think they are for tractors/hydraulic plant. There are hundreds of them in a box, so thought I would save a few pennies
I'm assuming these would be OK, or should I get motorcycle specific??
PS: sorry for all the dumb-sounding questions!

Those will work.

If you're worried about the washer you could anneal it. On my RD350, It had copper ring head gaskets, I used to just throw em on the grill for a bit and reuse em over and over and over.

At what point are you shifting down to first? I down shift a few times while rolling, but the only way to avoid a clunk going in to first is to wait until I am about to stop before hitting that last downshift.

oic0 wrote:

If you're worried about the washer you could anneal it. On my RD350, It had copper ring head gaskets, I used to just throw em on the grill for a bit and reuse em over and over and over.

At what point are you shifting down to first? I down shift a few times while rolling, but the only way to avoid a clunk going in to first is to wait until I am about to stop before hitting that last downshift.

yeah, I've always had the problem of clunky downshift to 1st & get down to walking speed/stop before hitting the shifter to get over this. The problem now is also downshifting from higher gears: I have a really nice corner locally where I shift from 6th doing around 80mph to 3rd or 4th with super late braking - I feel like the gearbox is getting hammered right now.....