Dirt Tricks KTM Timing Chain Tensioner - Dirt Rider Magazine

Like many other facets of its motorcycles, KTM has chosen to go a different route with four-stroke cam-chain tensioning. While other bikes use a spring-loaded tensioner with a locking ratchet system, KTM employs a hydraulic unit that uses the engine's oil pressure to keep the slack out of the chain.The tensioner was first put on the 250F, and we never had a complaint with it on that bike. Now, though, all of the latest KTM four-stroke engines use the same cam-chain adjuster. The only problems we've seen were on some of the single-cam XC-W and EXC models. When the engines get time on them, they get a ticking or clattery sound at idle. KTM claims the sound is nothing to worry about, but on our 400 and 450 XC-W and the Husaberg 450 the sound grew loud enough to concern us.Dirt Tricks makes a cam-chain tensioner that works hydraulically like the stock one, but it also utilizes a small spring and a mechanical ratchet system to hold tension when the oil pressure is low. The directions with the $69 part are very clear, and the install was quick and easy. Best of all, the cam chain went silent and never made another odd noise. The only issue is rare and applies to those who overrev the bike excessively while it is smoking hot; then the ratcheting system can cause premature wear, but you were already doing this to your machine by the way you ride it.If your KTM is making cam-chain noise at idle, you'll love this part. The directions even tell how to know if you need a new cam chain. Also, a tensioner is being developed for the big KTM twins. -Karel Kramer