ADVrider

Go Back   ADVrider > Bikes > Thumpers
User Name
Password
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 06-13-2010, 11:29 AM   #1
Chuck az OP
Gnarly Adventurer
 
Chuck az's Avatar
 
Joined: May 2010
Location: Columbus Ohio
Oddometer: 174
KTM 640 Camshaft install help..

I am putting back together my 640 after replacing the base gasket and I can't seem to figure out the origami needed to get the cam back in. The manual has about ten word dedicated to this step. I can tell the chain needs to go on the gear first but with that I cannot get the cam lined up with the sprocket because the bearing is holding the cam too high. I have searched here and have not seem anything describing the installation steps. I know if everyone had problems with it there would be a thread on it so I am sure it is just me


Thanks in advance
Chuck
Chuck az is online now   Reply With Quote
Old 06-13-2010, 11:54 AM   #2
wallache
Gnarly Adventurer
 
wallache's Avatar
 
Joined: Oct 2008
Location: PHX, AZ
Oddometer: 378
Its definitely a tight fit, takes some time to fight it back in. Tilt the cam down toward the sprocket and leave the small cam bearing off to give some working room. Is the timing chain tensioner removed?
wallache is offline   Reply With Quote
Old 06-13-2010, 12:08 PM   #3
Chuck az OP
Gnarly Adventurer
 
Chuck az's Avatar
 
Joined: May 2010
Location: Columbus Ohio
Oddometer: 174
The cam tensioner is removed, I was trying to do it just as you describe but no luck. I did not try too long this morning as I have to work today. I figured I would post for some advice before trying again tomorrow.

Thanks
Chuck az is online now   Reply With Quote
Old 06-13-2010, 02:06 PM   #4
makazica
Studly Adventurer
 
makazica's Avatar
 
Joined: May 2008
Location: Zagreb, Croatia
Oddometer: 736
Patience.

You can try to put the chain after you assemble the sprocket and cam.

Fiddle.
makazica is offline   Reply With Quote
Old 06-13-2010, 04:12 PM   #5
dnrobertson
Big Bike, Slow Rider
 
Joined: Jun 2008
Location: Frankston, Australia
Oddometer: 709
Quote:
Originally Posted by Chuck az
I am putting back together my 640 after replacing the base gasket and I can't seem to figure out the origami needed to get the cam back in. The manual has about ten word dedicated to this step. I can tell the chain needs to go on the gear first but with that I cannot get the cam lined up with the sprocket because the bearing is holding the cam too high. I have searched here and have not seem anything describing the installation steps. I know if everyone had problems with it there would be a thread on it so I am sure it is just me


Thanks in advance
Chuck
Chuck,

Just finished doing this to my 640A (three times, but don't ask). Here is how I remember doing it.

Steps.

1. Check timing marks on ignition flywheel are aligned. (look through sight glass, mine had moved enough to be out 1 tooth).

2. Put chain on cam sprocket (CAM IS NOT IN BIKE YET). Sounds simple, but I found it will only work one way. From the water pump side, pull timing chain towards you and place sprocket in behind chain. Now put chain on sprocket. Roughly check the alignment of the timing mark on the sprocket as detailed in the manual. You can lift the chain enough to rotate the sprocket if you need to move this "dot".

3. Now, with a bit of effort, insert the cam into the sprocket. You can angle the sprocket enough to insert the cam in. Try and align the marks on sprocket and cam before inserting, or you will have to do it again and again and .....

At this point the cam will drop down into place and you should be able to place the clip into its groove.

If you have to FORCE ANYTHING at any time, you are doing it wrong. It's like a jigsaw puzzle, only the correct way works.

Hope this helps.

David.
__________________
David

2005 KTM 640A
2008 Wee-Strom
dnrobertson is online now   Reply With Quote
Old 06-14-2010, 05:34 AM   #6
Tseta
Lost
 
Tseta's Avatar
 
Joined: Nov 2008
Location: Finland
Oddometer: 669
It is also possible that the camchain has slipped slightly and is now trapped/bunched at the lower sprocket - thus reducing the effective length of "available" camchain. This can happen if you have not kept the camchain taut while the camshaft was out of the engine. If you are lucky, you may be able to free this trapped chain and gain the necessary slack to install the camshaft by carefully rotating the engine while exerting a continuous and firm pull upwards on the advancing camchain.

Don't ask me how I know this... It was very nerve-wrecking at the time, hopefully no real damage was done. Eventually I got the camshaft on and the timing marks aligned. Next time I'll be sure to secure the camchain tightly.

Cheers,


Tseta
Tseta is offline   Reply With Quote
Old 06-14-2010, 11:44 AM   #7
Chuck az OP
Gnarly Adventurer
 
Chuck az's Avatar
 
Joined: May 2010
Location: Columbus Ohio
Oddometer: 174
In case anyone every reads this and wants to know how to do it:

1. Take the needle bearing off the end of the camshaft.
2. Slide the ball bearing (other end) out to about 1/8 inch from the end.
3. Hold the circlip with your index finger against the cam sprocket. Do not drop it in the case!
4. hold the cam sprocket at an angle and slide the cam into it with the timing marks lined up.

Once it is slid in and lined up you will be able to slide the ball bearing all the way back, slide the needle bearing on and put the circlip in place (maybe need a a pair of needle nose pliers)

There is only about a tenth of an inch to spare when sliding the cam in so be patient. The KTM manual says to put the circlip in place first. This will not work!

Now off to rebuild the water pump!
Chuck az is online now   Reply With Quote
Old 06-14-2010, 04:06 PM   #8
laramie LC4
crash test dummy!
 
laramie LC4's Avatar
 
Joined: Sep 2004
Location: Tucson, Az
Oddometer: 2,331
glad you got it. i remember struggling with that thing too many times. once you get it though, you kinda feel like a dummy for it taking so long in the first place. dont ask me how i know.......

laramie
__________________
DON'T TRUST CUT 7! HE IS A CROOK! ASK ME HOW I KNOW.

'12 LC8 990R, '02 LC4 640, '05 WR 450f (part-out), '98 XR400R, '76 KE100, '05 525 (Step-Child)
laramie LC4 is offline   Reply With Quote
Old 06-14-2010, 11:10 PM   #9
Chuck az OP
Gnarly Adventurer
 
Chuck az's Avatar
 
Joined: May 2010
Location: Columbus Ohio
Oddometer: 174
Yah i have been working on it in the morning before work and I think I needed to sleep on it one more night before my mind could grasp that puzzle. It is easy after yo get it done
Chuck az is online now   Reply With Quote
Reply

Share

Thread Tools Search this Thread
Search this Thread:

.
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


Times are GMT -7.   It's 05:27 AM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2014