xt660 crankcase knock diagnostic vids and fix! - .: XT660.com

bikemad195 · # 1 25-03-13, 18:08

ok so i thought i would share my personal fix and problem with my 09 xt660x as there is very little info on the net about this exact problem. the way it happened for me ....... ok so i bought my baby with 10500 miles on it a few months back and i took it for a long hard ride and came back with a knock under acceleration
i instantly thought the worst thinking i had killed the big end bearings as that was wear the sound seemed to be coming from. so i rode it for a few days to check it wasn't my imagination and there was still a knock there that was bothering me so i took it to 3 different local bike mechanics they all agreed it sounded "corse" but said its "just a big single and that's all the noise is keep riding it and see if it gets worse" so my mechanic instincts kicked in (car mechanic) and i new something was wrong as the sound had changed and sounded very metallic when accelerating / decelerating the engine from a fixed speed . i also realized that if i put it in gear and hold the front brake and try and drive (take up any slack in transmission ) it would sound just like hitting a hammer on the top of a vice. which cant be good so i did some research and found very little info on it so i decided i would strip the oil filter, water pump, clutch cover and arm, and the right hand side foot peg off so i could take the crank cover off. when i looked close i could see that the primary gears on the end of the crank shaft could be rotated a fair way either way before the shaft stopped it from rotating freely so i un folded the lock tab which had no signs of allowing the nut to spin and found once this was out the way i could rotate the nut off the end of the shaft by hand .... obviously this wasn't right so i tried some more research and found something to do with on the newer models the torque settings had been reduced even tho its the same components they just deiced to fit the newer engines with a lower torque measurement . so i found some were on the web which stated the older torque measurement was 110nm so i went and bought a new lock tab washer and some permanent lock tight and resembled the nut back onto the crankshaft (luckily they was no signs of wear or damage)

so with the lock tight and new tab washer i torques it up to 110nm which was rather tricky because of having to take up the transmission slack while on a paddock stand but i managed it in the end then i bent the tab washer over one of the flat sides of the washer and also manged to bend the other side of the washer into a triangle over the top corner of the nut i then rebuilt the bike put it all back together and have done 1300 hard miles since and there's still no knock

all this cost me about 4 hours of my time laid infront of a heater and about �10 for the new washed and loctite .

just thought i would share my story as i think it might be pretty helpfull for others cos when it first started i was prety worried thinking that sounds expensive lol
below you will see three youtube links of the knock and also of the fix

any questions just message me or comment below.ash
happy riding

vid 1 of knock http://www.youtube.com/watch?v=1yOV3...ature=youtu.be

vid 2 of more knocking noise http://www.youtube.com/watch?v=bEggx...ature=youtu.be

vid 3 the problem and fix http://youtu.be/Nyk4PWGVQgw

(i hope i have posted all this in the correct location)

Kev · # 2 25-03-13, 22:22

Nice work mate, we are seeing more & more of these loose nuts, first one was back in 2007.

bikemad195 · # 3 26-03-13, 00:33

Quote:

Originally Posted by Kev

Nice work mate, we are seeing more & more of these loose nuts, first one was back on 2007.

cheers i just thought i would make that thread due to been very little info on the web about it (or what i could find anyway)

Kev · # 4 26-03-13, 01:13

Like the videos, I am sure it will help other guys out.

xt660xroma · # 5 26-03-13, 06:23

hi bikemad195,

thanks so much for the videos! it helps a lot. yesterday I went to a yamaha mechanic who said that the noise from my engine was perfectly fine.....will check the third opinion and will show your video.

cheers,
davide

bikemad195 · # 6 26-03-13, 11:35

Quote:

Originally Posted by xt660xroma

hi bikemad195,

thanks so much for the videos! it helps a lot. yesterday I went to a yamaha mechanic who said that the noise from my engine was perfectly fine.....will check the third opinion and will show your video.

cheers,
davide

from my mechanical passed i find that if a customer or owner of a vehicle who uses it day in day out from cold and through all the variables and the say that something is different 99% of the time they are correct. in my case i rode it hard and it made the noise more obvious to me so i knew there was defiantly something wrong lol

Harryn · # 7 08-09-13, 06:24

BM, thanks for the post. I have 96 Ten which developed a death rattle that I was sure were the Big Ends. But sure enough, upon having a look after having read your post it was a loose nut ( no not the one behind the handlebars

). A tighten up with a shifter to the recommended tension ( dead tight plus half a turn) and all is well. The old girl purrs like the proverbial kitten.
Thanks again

H.

afk40 · # 8 09-03-14, 20:12

Bike mad,, theres no sound in your youtube vids,,, but in vid 3 is that the nut that needs tightened,,,??? as this is my exact noise heard from the site in another vid.... cheers.

afk40 · # 9 09-03-14, 20:31

subscribed

bikemad195 · # 10 09-03-14, 20:48

Quote:

Originally Posted by afk40

Bike mad,, theres no sound in your youtube vids,,, but in vid 3 is that the nut that needs tightened,,,??? as this is my exact noise heard from the site in another vid.... cheers.

its there it sounds like a hammer on the back of a vice if you hold the fron brake on and bang it into gear and apply power trying to move forward it knocks its head off same as on deceleration and yes it needs that nut taking off and apply some premanent loctite and a new tab washer . u used the same washer but did one tab over a entire flat side and then the other unused tab i folded into a trinagle over the corner hexagon of the nut

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