Hey just got my 2006 KTM 250sxf rebuilt for the second time and for the most part it runs as it should. Although now there is intermittent valve train noises,(as if it was getting no oil). When it makes the noises it also raises in rpm, not a lot, maybe a couple hundred. The valve train is torqued to factory spec's and the shims are all good. There is fresh oil along with a filter. The first time I had it running the engine was quite as a mouse, all I've done since then is replace the piston with the OE compression piston. After its first start up early this morning it ran and sounded great but now (approx 5 hours later) the bike has this valve train noises. It sounds as if the tensioner isn't working correctly but I'm not sure. Do these bikes have chain tensioner issues? Or should I be looking for something else. I did notice the oil pump has to be timed up during reassembly, and I'm 99% sure that part is correct. Any help would be great. Thanks.