ADVrider

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

Reply
 
Thread Tools Search this Thread Display Modes
Old 07-06-2008, 08:51 AM   #1
kamanya OP
Andrew to most
 
kamanya's Avatar
 
Joined: Jun 2004
Location: Southern Tip of Africa
Oddometer: 1,275
Changing the cam chains and balancer shaft bearing

Ok, major work.

I have always had a very noisy engine, the cam chains particularly on the right hand side or rear cylinder make quite a bit of noise. The dealers mechanics could never eliminate it or pin it down. I have opened it up a few times myself trying to figure it out.

Recently I was just passing the bike on the way to get into the cage and whilst staring at the thing I was idly fiddling with the starter button, just pushing it enough to get the engine to turn over but not to fire. Yes it’s a stupid thing to do but… stupid is a stupid does. Suddenly it back fired and something didn’t sound right when it did.

I started it up and now there was a totally new loud and very worrying valve type noise going on?! Something was definitely not right.

The thought of having to go back in was a bit irritating but, along with fixing this new problem I was determined to find out once and for all what was causing the clatter. As I got into the valves I realised that the front cylinder cams were completely away from where they should have been at TDC. AHHHHH feck! This could be really serious!

This is what I think had happened; when it backfired there was no oil pressure to keep the cam tensioners tight and in turning backwards the chain had slipped a couple of teeth. When I ran it straight after I did the backfire thing, what I could hear was the valves running totally out from where they should have been. It was possible that the chain may have slipped enough to have the valves hit the top of the piston. So to check this I had to take the head off. This was turning out to be a lot more work than I had anticipated.

It was at about this time that I decided that if I was going to go this far in I might as well check the lengths of the cam chains too. I really do not believe that my motor is just a “noisy one” and decided that I was going to replace my cam chains and cam chain guides and to try to see if I could not figure this irritation out.

That got me to here. No damage to the piston or valves, I was lucky.



To get the cam chains out you have to take the balancer shaft out. That’s the shaft above the flywheel/rotor.



To get that shaft out you have to undo this nut.


And this one, the balancer shaft retaining nut.



Both are impossible without locking the engine with the locking bolt.

Also put the green Loctite on the screws in here so they dont go walkbout.




Once that is off there is a special little torture test getting the two woodruff keys out of the shaft to get the balancer and cam gear off.

Once I got those off, I finally found what I believe is has been causing the clatter that I get from the engine. This is the left balancer; you can see the rear cylinder cam chain has bitten into it. The wear is all the way around the balancer – deeper where it picks up the chain and less as it turns.




The guide for the above balancers’ chain is the one on the right; you can see that the chain, unlike the one of the left, does not run straight down the guide. There is very slight play in the bearing of the guide (but the play is the same for both).



The locking screw for the balance shaft bearing on the right side of the motor has also seen some wear from the cam chain;



The cam chain for the other side has also worn the balancer although not as bad;



I did check the cam chain tensioners and the length of the spring that regulates the oil pressure. All were in spec. Ultimately what happens is that for some reason the cam chains operate very close to the balancers. The balancer clips the chain and causes the perpendicular flutter that cannot be damped by the tensioner and causes the cam chain clatter that can be heard at lower revs. It also sets up some horizontal movement that then bites into the bearing retainer screw.

I consulted with the head of technical services for KTM in South Africa. He was pretty helpful and suggested after chatting to the propeller heads in Austria that the balancer shaft bearing may be at fault and I need to get them out. They think that the shaft has more play left and right than it should have and the left hand bearing is supposed to prevent this.


How do you get the left balancer shaft bearing out? Good question. That’s the one next to the worn screw in the above picture. There are some expensive solutions that call for splitting the cases or bearing pullers but a simple method is…. A broom stick! The left hand bearing... the one above the crankshaft here



has a bigger inside diameter than the right (the one I wanted out) and amazingly I happen to have a broom stick that happened to be the right diameter to fit through the above bearing yet not the right and I could drive the right hand bearing out from the left hand side. A word of caution though…

This left bearing has a race in it that has a lip on the engine side of it that prevents the race from falling out.




There is a retaining lip on the inside of the case that stops the race from coming into the engine. This retaining lip does not run the whole way round, it is a half moon. When I drove the bearing out the race got stuck on the broom stick. I didn’t see this as a problem as all I had to do was now drive the broomstick out the race. What I should have done was pull the stick all the way through and pull off the race. But I just gave it a few taps. The race came off the broom and promptly fell into the crank case. This happened because the case lip does not go the whole way around the case. The race once it came off the broomstick, fell into the case. So there I was swearing that I had a race sitting somewhere deep in the bowels in-between the cranks somewhere. It is a very depressing predicament to be in. Fortunately for me I had already taken the front cylinder head off. So I was lucky in that by turning the front cylinder to TDC and pulling the barrel up a bit I could see the race nestled at the bottom of the crankshafts and it was easy to hook it out. You don’t want to have to do this.

The bearing had quite a bit of lateral play in it. So I think that the balancer shaft was able to move laterally, this causes the balancers to catch the cam chains and causes the clatter. What I think is the cause is that the bearing had not been pushed in far enough and had not seated properly. this allows the race too much play and thus the shaft can move too much and causes the cam chain flutter when the balancers nick the cam chain.

Those bearings are expensive. But then anything with a KTM sticker is. In hindsight the old bearing is fine, it just needed to be driven in a bit more. Ahh well I now have a new bearing in there.

Now that that had been changed, to the cam chains

Old vs new one. Interestingly I couldn’t find any wear marks on the chain from hitting the balancer. They both are markedly longer than the replacement ones.

Rear cam chain with replacement


Front cam chain with replacement


I also bought a pair of the longer tensioner bolts, they are about 5mm longer, sorry I didn’t take a pic of them. (edit - here you go)





Putting everything back together went smoothly. I turned the engine over a few times to see if everything was sounding as it should, then hooked up some petrol and turned on the ignition. No fuel pump noise?

This might be the problem.





I cleaned it up as best I could and got it running again but I am going to have to get a new one.

Once that was fixed, hit the starter and it fired right up.

And bonus of all bonuses, it purrs smooth as silk with not a rattle or a clatter to be heard. It doesn’t even make the normal cam chain noise at startup.

Lastly I put some grip warmers and two new HID's in - its quite a squeeze to get it all in there. Had to move the hooter.



They are really really bright, I can't wait to try them in the dark.



I went for a ride today and even the rain couldn't keep the smile from my face.



I am in love again.
__________________
I often wonder where that road goes? And that, has usually made all the difference. Appologies to Mr Frost

kamanya screwed with this post 08-22-2013 at 03:14 AM
kamanya is offline   Reply With Quote
Old 07-06-2008, 09:13 AM   #2
PABiker
Anywhere but here
 
Joined: Dec 2006
Location: Pittsburgh
Oddometer: 3,749
Nice work.
__________________
'03 Suzuki V-Strom 1000
'12 Suzuki DR650SE
'10 Husaberg FE450 Plated
PABiker is offline   Reply With Quote
Old 07-06-2008, 09:56 AM   #3
adiablolex
Lost again
 
adiablolex's Avatar
 
Joined: Jul 2007
Location: Third rock from the Sun
Oddometer: 3,693
more of an awesome investigative report if you ask me.
How many K's on the bike ?
__________________
DRCOOL rides with me
adiablolex is offline   Reply With Quote
Old 07-06-2008, 10:08 AM   #4
Steffo
Gnarly Adventurer
 
Steffo's Avatar
 
Joined: Feb 2008
Location: Stockholm, Sweden
Oddometer: 211
Wish I had the skills, and the guts, to do surgery like that. I just started my "med school" with installing the 12V Outlet and the KTM Alarm on my 950.
__________________
2009 BMW F800GS.
Steffo is offline   Reply With Quote
Old 07-06-2008, 10:11 AM   #5
markjenn
Beastly Adventurer
 
Joined: Nov 2003
Location: Swellvue, WA
Oddometer: 10,308
Great work and great attitude. You really worked through some thorny issues that would have most of us tearing our hair out.

- Mark
markjenn is offline   Reply With Quote
Old 07-06-2008, 10:14 AM   #6
Steffo
Gnarly Adventurer
 
Steffo's Avatar
 
Joined: Feb 2008
Location: Stockholm, Sweden
Oddometer: 211
Quote:
Originally Posted by markjenn
Great work and great attitude. You really worked through some thorny issues that would have most of us tearing our hair out.

- Mark
..and crying like little girls at that.
__________________
2009 BMW F800GS.
Steffo is offline   Reply With Quote
Old 07-06-2008, 10:38 AM   #7
kamanya OP
Andrew to most
 
kamanya's Avatar
 
Joined: Jun 2004
Location: Southern Tip of Africa
Oddometer: 1,275
Quote:
Originally Posted by adiablolex
How many K's on the bike ?
29000km. It is an 04 model.

Most of them have been ridden pretty hard.
__________________
I often wonder where that road goes? And that, has usually made all the difference. Appologies to Mr Frost
kamanya is offline   Reply With Quote
Old 07-06-2008, 07:50 PM   #8
adiablolex
Lost again
 
adiablolex's Avatar
 
Joined: Jul 2007
Location: Third rock from the Sun
Oddometer: 3,693
Quote:
Originally Posted by kamanya
29000km. It is an 04 model.

Most of them have been ridden pretty hard.
reason I asked cause mine is an Ofour 23k, think I'll get into her in the winter as a preventative measure. Are those longer plugs for the tensioners an upgrade? I know some noise is normal but this is not my kind of normal noise.
__________________
DRCOOL rides with me
adiablolex is offline   Reply With Quote
Old 07-06-2008, 08:01 PM   #9
ADVJake
***** dweller
 
ADVJake's Avatar
 
Joined: Aug 2004
Location: Sydney, Australia
Oddometer: 4,339
That same noiise is what Mudguts and I are getting.
So we have to replace balancer shaft bearings & the cam chains too?
Only at 35,000kms
__________________
"And some guy said, let there be filtering, and we filtered and we saw that it was good, and hours became minutes..."
ADVJake is offline   Reply With Quote
Old 07-06-2008, 08:14 PM   #10
adiablolex
Lost again
 
adiablolex's Avatar
 
Joined: Jul 2007
Location: Third rock from the Sun
Oddometer: 3,693
Quote:
Originally Posted by KTMJake
That same noiise is what Mudguts and I are getting.
So we have to replace balancer shaft bearings & the cam chains too?
Only at 35,000kms
I don't know if the new chains are redesigned but the way Kamanaya is comparing the two side by side seems like there's a bit too much stretching going on.
Any of you guys try the longer cap bolts for the tensioners?
I'm throwing the idea around to put something there so the chains don't rattle loose as they fill up with oil.
__________________
DRCOOL rides with me
adiablolex is offline   Reply With Quote
Old 07-06-2008, 10:56 PM   #11
cpmodem
Orange Caveman
 
cpmodem's Avatar
 
Joined: Nov 2004
Location: masa yee yah tee 59 14' 9" N / 135 26' 42" W
Oddometer: 7,103
Sounds from kamanya's excellent article that this was caused by an improperly installed bearing. Not likely to be a systemic problem.
__________________

-cp

DISCLAIMER: All observations made in this post are mine and based solely on my own anecdotal experiences, and may contain large doses of facetiousness. YMMV, of course. You are "on your own", and I take no responsibility if someone tries anything in this post and gets into trouble with the law, damages their person or property, or goes blind. Take everything you read or hear "anywhere" butt especially on the Web with a large dose of salt.

cpmodem is offline   Reply With Quote
Old 07-07-2008, 12:21 AM   #12
gefr
Life is a trip
 
gefr's Avatar
 
Joined: Nov 2005
Location: East Med, Greece
Oddometer: 3,732
The balancer shaft is kind of stuck in there.

As I realized watching my technician working on one. How do you take it out? Do you hit it with a hammer from the back side or do you pull it with an extractor tool? Cheers.
gefr is offline   Reply With Quote
Old 07-07-2008, 12:46 AM   #13
kamanya OP
Andrew to most
 
kamanya's Avatar
 
Joined: Jun 2004
Location: Southern Tip of Africa
Oddometer: 1,275
Quote:
Originally Posted by gefr
As I realized watching my technician working on one. How do you take it out? Do you hit it with a hammer from the back side or do you pull it with an extractor tool? Cheers.
Mine came out pretty easliy with a few whacks from a rubber hammer. I dont think you can pull it out by hand, it is pretty tight. The manual says,

Quote:
Gently tap the balancer shaft off on the clutch side with a rubber hammer.

CAUTION !
MAKE SURE THE TIMING CHAIN DOES NOT GET CAUGHT.
NOTE: a stop disk is located on the outside of the roller bearing on the balancer shaft (on the clutch side) which should be removed before the balancer shaft is dismounted.

Remove the timing chain and unscrew the tensioning rail.

NOTE: if you intend to reuse the timing chain and chain tensioning rail, mark the running direction and the cylinder allocation.
__________________
I often wonder where that road goes? And that, has usually made all the difference. Appologies to Mr Frost
kamanya is offline   Reply With Quote
Old 07-07-2008, 01:02 AM   #14
kamanya OP
Andrew to most
 
kamanya's Avatar
 
Joined: Jun 2004
Location: Southern Tip of Africa
Oddometer: 1,275
Quote:
Originally Posted by KTMJake
That same noiise is what Mudguts and I are getting.
So we have to replace balancer shaft bearings & the cam chains too?
Only at 35,000kms
The balancer shaft bearing I think will be fine, if it is not seated properly then evidence of this will be on the balancers where they catch the cam chains.

Mine on occasion had a good clatter going and it was distinct from just cam chain rattle. This clatter when it did happen was not just on start-up but anytime the revs dropped. What baffled me was I just had the rattle and occasionally the rattle and the clatter.

Now I know that the clatter happened when the shaft had moved.

Because of this, I presume that the cam chains were prematurely aged and stretched.

If when you check yours cam system, if you can get more than a 2mm of play (mine had about 5mm) from the race then you need to drive the bearing in to properly seat it. Of course take care when you drive it in not to damage the bearing.

Also, when putting the balancer shaft back, I can imagine that there is a chance that when tapping in the shaft that it moves the bearing out again if you haven't put the bearing locking screw back.




The cam chains are exactly the same in type, the only difference I could see apart from the wear was that the old ones had a single letter stamped on it - can't remember now but I can go look when I am back home. The new ones had "DID" and a few other things stamped on them.
__________________
I often wonder where that road goes? And that, has usually made all the difference. Appologies to Mr Frost

kamanya screwed with this post 07-07-2008 at 01:27 AM
kamanya is offline   Reply With Quote
Old 07-07-2008, 01:25 AM   #15
kamanya OP
Andrew to most
 
kamanya's Avatar
 
Joined: Jun 2004
Location: Southern Tip of Africa
Oddometer: 1,275
Quote:
Originally Posted by adiablolex
reason I asked cause mine is an Ofour 23k, think I'll get into her in the winter as a preventative measure. Are those longer plugs for the tensioners an upgrade? I know some noise is normal but this is not my kind of normal noise.
The longer tensioner bolts are an upgrade that comes from KTM. The part number is 60036008100.

Getting the bolts for the older engines might be something that gets a few more miles out of your cam chains. But unless you have the issue I had I think they should be fine for a fairly long time.

I don't know why so many older engines are noisy and none of the newer ones are? They must have changed something. If you look at what is in the older and newer engines they use exaclty the same chains, tensioners and guides. What is diferent is what they call a "spreader gear" in place of the timing gear on the end of the balancer shaft on the clutch side. This must be what makes the difference. How, I don't know?
__________________
I often wonder where that road goes? And that, has usually made all the difference. Appologies to Mr Frost
kamanya is offline   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 03:34 PM.


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