This little story should convince you. It's a bit embarrassing but I'll tell it for your benefit(I was probably going to post it anyway). Just this last weekend, I had the left hand side drain bolt go missing while trail riding. I still can't believe it, I've never had this happen before, but it seems as though I didn't tighten it enough. The bike could have been sabotaged because it was sitting outside the tent all night, but I guess I'll never know. Very strange, but most probably my fault. Anyway, we'd done about an hour and a half of sandy trail riding, and then slowed down the pace a bit when the engine started making screeching noises. I thought to myself, "The bike is only twenty hours old, surely that sound couldn't be the clutch or anything else in the engine!" I should have stopped to check the bike out, but I didn't want to get further back in the pack, and I concluded that it must be a stick rubbing on one of the brake rotors. When we got to the check point, I checked the bike over and to my surprise the drain plug was gone and a mixture of oil and sand was gathered on the frame!
I'd noted before that the sump plug had gotten smaller on the new model, 8mm diameter, and the seat bolts had gotten larger, also 8mm diameter, so I used the seat bolt to replace the plug and zip-tied the seat on; very handy!
I asked around and even though there were about four utes at the stop, nobody had oil. The bike got loaded up onto the recovery trailer and we headed up to the lunch spot. The guy that gave me a lift in his ute asked around and one of the lead riders had a litre of oil that I could use; I was thrilled! I poured the oil in and after about three kicks she fired up with no screeching or any other unusual sounds. I don't know exactly how much oil it took to fill her up, but it was close to a litre. I rode for another couple of hours in deep sandy trails that same day and another hour on Sunday. I got a bit worried while riding on Sunday because I could smell oil and I thought my bike felt like it was starting to seize up, but I was glad when I realised it was actually the two stroker in front of me that I could smell and I must've just imagined the performance deterioration! Needless to say, I don't want to experience that little unpleasant occurence ever
again! I'd say, after all that, that yes
, the '06 YZ450F is very reliable.