.: XT660.com - The #1 XT660 Resource :. - loose balancer ? (video)

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- - loose balancer ? (video) ( https://www.xt660.com/showthread.php?t=23901)

loose gearbox input shaft ? (video)

Hello friends,
I'm trying to locate knocking noise from the engine,
So far I checked crank bearings and nuts, i also replaced timing chain and checked tensioner ,
But I can not find the knocking.

I also checked the balancer and discovered a kind of free play (video attached)
dont know if that's ok or not,
what do you guys think, is this normal?

That isn't the balancer shaft, it's the gearbox input shaft (where the clutch fits). The balancer shaft and drive gear is the one above and to the right.

AFAIK there is no "end float" measurement mentioned by Yamaha, but a little is normal to allow for expansion/contraction as the engine warms/cools. It is difficult to tell how much you are moving the shaft in and out. Have you measured it?

Most bikes I've had that have gearbox shaft end float figures given tend to be in the 0.05-0.15mm region.

One question you might find difficult to answer now with the bike in pieces is, does the rattle/knocking sound go away when the clutch (lever pulled in) is disengaged?

Quote:

Originally Posted by ram (Post 209721)

You're listening to the knock.of the cogs around the crank due to it's nut becoming loose I have just retorted and locked mine at 120nm for the 2nd time 10.000miles between and there is no way my nut could of rotated I was talking to someone the other day and the only way this could be happening is the crank is slowly stretching ... which makes sense how can we tighten something and it not rotate but become loose when it's against a stop .... best answer I've heated so far ...... if u luck for a vido on youtube you will find videos under "xt660x knock" both of the noise and what's causing the noise .... the channel name is "Marvy finger bottom" lol don't ask.... may also come up under "bikemad195" can't provide links as I'm laid in bed on my phone lol

Quote:

Originally Posted by bikemad195 (Post 209746)

Just made a play list of noise and fixXt660 primary drive nut: http://www.youtube.com/playlist?list...s3MyCuVkSQuKKP

Hi! I also have that free play on the gearbox shaft and about the same amount. First I thought the clutch basket is loose but it's the whole shaft moving. Oh well, so many noise sources on that engine, crankshaft nut on my XT660R was not finger loose, but I still managed to tighten it a fair amount until 120Nm. Haven't started the engine yet, still have to check valve clearances, but hopefully it will make less noise then.

Not sure if its any help but I have my motor in pieces at the moment and the clutch basket has absolutely no play in it at all, rock solid. I will be removing it next month when I have the tools but until then cant say if the shaft moves without it.

When i checked primary drive nut, i also noticed that i have free play of clutch basket. What can cause free play?

Quote:

Originally Posted by bikemad195 (Post 209746)

The crank doesn’t stretch, it’s the crankshaft washer that wears; this also caused the vast amount of vibration (metal to metal rubbing) when worn.
This give the illusion of crank stretch but as you know the nut is still fully Loctited, so does give the impression and add to the illusion!

Just fitted my third washer this year! And taken Minky’s advice and torqued the crankshaft nut up to 120Nm, but some have taken this higher (just be careful as if the bearing preload is too high there will be increased bearing wear).