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matsplatuk 11-01-2005 10:04 AM

LC4 rocker arms
 
During my firts valve clearance check (Thanks Creeper for your exelent guide) i noticed that the inlet rocker arm moved laterally along its shaft. This didn't seem to heppen with the exhaust rocker arm 'till i took the upper cylinder head assembaly off. Now they both move about 1mm side to side on their shafts. Is this OK?

I did a search but only found one mention of inlet rocker arms failing on older machines but that was it. Does anyone know more on this?

Thanks, in advance - Mat

http://snap24.photobox.co.uk/0825853...d0f7e573a7.jpg

Loadedagain 11-01-2005 10:12 AM

whoa.... now i see why that bearing needs replacing at regular interval... it's flippin tiny!

creeper 11-01-2005 10:13 AM

Using your photo as a reference, see the shims on the drive side of the cover? KTM recommends those to be 1.00mm thick to establish rocker arm position.
Then you fill the gap on the spark plug side with shims to obtain an end clearance of 0.20mm to 0.030mm.

Shims are available in 0.015, 0.030, 0.050 and 1.00mm.

C

Loadedagain 11-01-2005 10:14 AM

ps... rockers should float on the shafts. i'm not sure of allowable end play, but 1mm doesn't seem too bad. i'll have a peek in the manual for a spec... betcha creeper beats me to it though.

Loadedagain 11-01-2005 10:15 AM

Quote:

Originally Posted by Loadedagain
betcha creeper beats me to it though.

told ya....

creeper 11-01-2005 10:22 AM

Quote:

Originally Posted by Loadedagain
ps... rockers should float on the shafts. i'm not sure of allowable end play, but 1mm doesn't seem too bad. i'll have a peek in the manual for a spec... betcha creeper beats me to it though.

Just did one a few days ago... :ksteve

matsplatuk 11-01-2005 11:34 AM

Oh OK, i think i understand,

I leave the 1mm shim on the cam chain side but then add shims to the spark plug side so the total play/gap on the shaft is 0.2 - 0.3mm?

Is this something worth doing or will it be safe to leave it till another day?

I suppose i just go to a dealer and ask for LC4 rocker shaft shims?

Funny that this procedure isn't mentioned in the LC4 motor manual ive got.

Many Thanks Guys - Mat

creeper 11-01-2005 11:47 AM

Quote:

Originally Posted by matsplatuk
Oh OK, i think i understand,

I leave the 1mm shim on the cam chain side but then add shims to the spark plug side so the total play/gap on the shaft is 0.2 - 0.3mm?

Is this something worth doing or will it be safe to leave it till another day?

I suppose i just go to a dealer and ask for LC4 rocker shaft shims?

Funny that this procedure isn't mentioned in the LC4 motor manual ive got.

Many Thanks Guys - Mat

Right out of the book...

Quote:

NOTE: Discs bl are available 0.15 mm, 0.30 mm and 0.50 mm thick.
– Mount new O-rings bp on rocker arm shafts 1.
– Mount rocker arms 2, thrust washers 3 and rocker arm shafts 1.
– On the side of the water pump one thrust washer bn ≪ 1.0 mm (0.04
in) must be mounted.
– The axial play on the opposite side is roughly equalized with thrust
washers 3 ≪ 1.0 (0.04 in) and ≪ 0.5 mm (0.02 in).
The axial clearance of the rocker arm axles must be 0.20 - 0.30 mm.
Considering 1.0mm is over three times what KTM recommends as a maximum end play, you should probably take care of it now.
It's not just end play, but potential acceleration and deceleration of the rocker arm laterally. The more play, the greater those forces, the greater those forces the more thrust and wear they can generate.
At least that's the viewpoint I would take.

C

matsplatuk 11-02-2005 12:26 AM

Thanks Creeper, ive now found the page in the service manual.

Tseta 01-04-2009 11:28 AM

Hello,

First of all, I'm sorry for digging up such an old thread. However, I searched the site and the Index Threads, and this thread is very closely related to my current issue.

As I was checking the valve clearances (valve lash?) on my 2003 LC4 Adventure, I discovered that the exhaust side rockers had about 0.7mm of axial clearance, while the intake side rockers were right on (based on the information in this thread, at least...) at 0.3mm. (The bike currently has approximately 18tkm on it, but as I just recently acquired it, I have no further knowledge of previous usage or maintenance.)

Even though Creeper already wrote a few words on the importance of having the correct axial clearance on the rockers, I am still slightly confused as to exactly what harm will the excess clearance cause?

In addition, I am hoping that some of the more knowledgeable folks could chime in on this thread, specifically on how to actually adjust the clearance on the rocker arms. It is my current understanding that the process is quite tedious, involving taking the engine out of the frame. There seems to be minimal room to even perform simple valve clearance inspections and adjustments with the engine in the frame.

So, should I start reading/translating the Indexed engine removal guide in preparation for the clearance adjustment or just relax about the whole issue and deal with it "later"?

Thanks,

Tseta

gunnerbuck 01-04-2009 12:58 PM

Tseta,
You do not need to remove the engine to shim out too much rocker play.... You need only to remove the valve cover and these instructions will help guide you: http://www.advrider.com/forums/showthread.php?t=112127 The shafts and rockers are contained within this cover so it is easy to work on...


With the cover off, the rocker shaft will then slide out as the cover mounting bolts are what hold them in place.... What you will need is a selection of the shims so you can swap them out to obtain the correct play...

Good luck...
David..

wrk2surf 01-04-2009 05:43 PM

3 years ago I actually lost or wore one out and half of it ended up in the clutch cover bearing near the front that lead to the starter not working correctly for months I chased this problem.... so I would say to always have those shims right on.

Tseta 01-09-2009 11:37 PM

Closure
 
Thanks to gunnerbuck and wrk2surf for their insight on this issue, and of course to Creeper for his excellent rocker cover sealing guide. With these and various other bits of information, I adjusted the axial clearance of the exhaust side rockers by adding a 0.5mm thick shim. Now the clearance is spot on.

Cheers,

Tseta

gunnerbuck 01-10-2009 08:13 AM

Thank you for letting us know that things worked out....

David...

creeper 01-10-2009 04:11 PM

"Spot on" is always good. :wink:

C


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