Engine knocking sound at low RPM

Hi all,

I'm totally new to 4T engines, and recently acquired a 2009 FE 450. It had that knocking sound at low rpm, and after a bit of research it all pointed to a faulty cam chain tensioner. I replaced the cam chain tensioner with a new OEM one, and I did the trick of compressing it with two washers on either side. After installing it, upon first start, the noise disappeared. Upon second start, the noise was back. I took the CCT out, reset it again with the two washers, replaced it as per the manual, and same thing. First start fine, second and subsequent starts the noise is back.

Anyone have any ideas what else could be the cause of the noise?

Thanks for your inputs Tourist. My bike sounds exactly like the two bikes in the vids. Unfortunately I'll have to order a manual CCT from the US, as nobody seems to stock them locally.

The way I understand the workings of the OEM one is: You compress it with the aid two washers to stop it 2-2.5 mm from being completely compressed. Then you replace in into the cylinder, and tighten the outer nut. With the inner still removed, you use a small screwdriver or something, and click that little button on it, which will cause it to extend and put pressure on the timing chain via that rail. The OEM unit works with oil pressure to extend it while the engine is running. I suspect that after first start, it contracts slightly, and upon second start, there might not be enough oil pressure to extend it again. While a manual CCT might make the noise go away, I think there might be another problem that needs attention.

I spoke to a mechanic at a local KTM shop, and he said it could also be valve clearances and/or not enough engine engine oil. Could also be an oil pressure problem. I'll drain the oil tonight and put fresh oil in just as a last resort for things that I can do myself, thereafter I'll have to load it and take it to the shop.

Man oh man, I really hope its not one of those problems that take 5 months to solve(financially). I had big plans for this baby :killerheadache:

Hi keyowne.

I will post a vid as soon as I get a chance to fix the oil drain plug that was stripped by the previous owner. I only noticed it this morning when I wanted to drain the oil.

Thanks for all the comments and suggestions so far guys!

And then if I understand what I've seen correctly, the tensioners can relax slightly - see video - but then only slightly and will not be helped by the spring to extend to the same position ... ?

Click to expand...

Thats the way I understand it as well, seems the oil pressure helps to extend it to the correct position.

I've only had it since Saturday, so I have no idea what oil is in the motor at the moment. According to a mechanic at a local KTM shop, it could also be one of the reasons for the sound at low rpm, other than the most common cause, which is the CCT.

Thanks everyone for all the advice so far!

I will def go for a ride and gas it hard and see what happens to the noise afterwards. Hopefully with the new CCT the noise will go away. I will also make sure to get the correct oil. Currently temperatures range from 15-35*C over here, so I will have to factor that in for my oil choice. I use Shell Rimula(called Rotella in the US) on my '13 300, since that is what Rekluse recommends. Hopefully I can use that on both bikes.
I first have to remove the engine though, because the oil drain plug's head is stripped, and I cannot get into that tight space to use an Easy-out on it. I'm currently doing it in small sections, as it's quite a job to do all in one go.

I'll keep you guys posted.

I like your Youtube channel OldMan!
My bike's noise comes more from the top part of the engine, rather than from the ignition cover. It's also only present at low rpms.

OK, so finally the noise is gone.

What a mission. After installing a new CCT, I wanted to change the oil and discovered that the oil drain plug was stripped. There is not enough space between the frame and the engine cases to use an easy-out, so I had to remove the engine, which is quite a mission.

That engine fills up the chassis so much so, that it is impossible to remove all the dirt without at least taking off the tank, and cleaning the engine and wires by hand. When I bought the bike, it looked fairly clean, but upon stripping it, and removing the engine, I could not believe how dirty it was. The first owner rode the bike where there is that super fine dust, which gets in everywhere. You cannot believe what mission it is to clean that dust off the cables and connectors. You basically have to scrub each cable with a toothbrush with an alcohol based solution. I had to use ear buds to clean the connectors, of which I did a pretty crappy job at best. Its just plain impossible to remove all the dust and dirt.

Once the engine was removed, I figured that I might was well check the valve clearances, timing chain and chain rail/guide, as was suggested on this forum and by our local KTM wiseass. When I started removing the cams etc, I thought I might as well check the top end, con rod etc, especially after noticing how dirty the inside of the bike was. So further down the rabbit hole I went. I was really worried that I ended up buying a bike that will cost me more to fix that I paid for it. I don't have much mechanic experience, and this was the first 4T I ever worked on, so it was quite confusing/scary at best of times.The piston ended up being fine, and it was suggested by an experienced mechanic/friend to just replace the cam chain and the piston rings after I took the engine to his place to have a look at it. The CCT rail and guide was fine. The Maccie also said the bottom end was still good. After 170 hours, the valves were bordering on the high end of the tolerance range, so I put larger shimms in as well.

Quite a few stripped bolts and threads here and there, and waiting for parts most of the time, I finally put the bike back together. After quite a struggle with getting the tank back on, and removing the right radiator retaining bolts at least 10 times, the bike was ready to start.

Click click nothing..... My worst nightmare came true. And worst of all, the FI light bulb was done, so I could not even get an error message from it. I checked and checked and checked everything again. Removed all the electrical connectors to make sure the contact cleaner evaporated completely. Checked the spark plug(partially remove radiator again) to make sure it was producing a spark. I then thought I might have messed up one of the connectors, or perhaps broke a wire in the stripping/assembly process. Later that afternoon I was back in the garage, hoping to find the culprit, before I had to resort to taking the bike to the KTM agents. After quite a long time of searching, and nearly cancelling my date for that evening, I found that one of the plugs that connect to the FI unit was not plugged in :-|
Plugged it in, pressed the e-start button and KABOOOOOOM! Followed by thousands more KABOOOMS! The bike was running, and I had my happy ending 5 hours before my date arrived