A little LC8 Tech Talk:
2005.5 KTM Adventure 950
Chasing Excessive Engine Noise
by Dieseljo
I purchased this motorcycle with 8,000 (well cared for) miles from the original owner.
At 10,600 miles I had the (by now) classic water pump shaft (seal) failure. Only to be noticed by a flickering oil psi light when the engine was up to temp (warm). The engine oil (when viewed with the human eye) did not look milky/coolant deluded. NOTE: With this engine, the paper type (stock) oil filter is one of two ways, in identifying a leaky water pump seal (before you destroy your engine.) Why? Because the paper filter clogs easily with coolant, reducing oil psi, turning on your oil psi light and drawing your attention to the problem. Or you could purchase a CJDesigns clear clutch cover, then you can see the moisture build up on the clear lexan face of the cover. With the Water pump repaired I headed back out on the trails.
At 12,200 miles my motor developed this horrible noise, which after many years of turning wrenches sounded like a very loose cam chain. The noise was odd and would sometimes go away if I shut off/restarted the motor. Installing a temporary oil psi gauge I could see the motor had plenty of oil psi when cold or hot. As noted by KTM the oil psi relief valve (for my year motor) had some issues with the internal spring. Seeing that the cam chain tensioner was the next stop in the oil flow after the relief valve, I decided to update the oil psi relief valve with the new part number, running the engine after completing this update verified the problem had NOT been repaired. The horrible engine noise was still there. I then pulled out both cam chain tensioner lifters and proceeded to inspect them. There it was… I found the noise… the rear cylinder cam chain tensioner lifter would stick (like a hydraulic lock) when compressing the inner piston to the bottom of the outer bore (you can do this with your fingers). It would only become un-stuck after injecting 35+ psi of shop air into the oil side of the lifter. I replaced the cam chain tensioner lifter, started my engine, and no more horrible engine noise. In fact the motor is running smoother than ever especially at low RPM. Now I am putting the 17″ wheels on with EBC HH pads (supplied by CJDesigns) to thrash the roads with my favorite most universal bike ever.
IMPORTANT NOTES: 1. Why did the lifter fail? We think it may have been (internally) scored when the coolant was running through the oil side of the engine during the water pump shaft failure.
2. We know when the engine is not running the cam chain tensioner lifter is near fully collapsed in the bore. On one end the cap is holding the lifter in and the other end the tesioner/ chain slide is pushing the lifter towards the cap. At start up the lifter internal spring pressure is used to push the piston out (keeping some tension on the slide) until oil psi arrives to take over. In a motor without a stretched cam chain the oil psi takes over within a couple seconds of start up.
3. I have read some posts about shimming the cam chain tensioner lifter. I do NOT recommend doing this. Especially after working out the math of the lifter travel and reviewing how the lifter cap keeps the lifter centered in it’s bore. If/when your cam chains become stretched, it is time to replace, not shim.
This is what the Tensioner looks like:
If you think you are in need of these email me. We have these in stock ready to ship to get your bike running it’s best Fast!
Thanks and safe travels,
Craig
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