Hi there. I've been looking around an havent been able to find any information on the bottom end of a honda nsr 150 an i was wondering if anyone would be able to help me out. the bike had a knock in the motor at around 4,000 rpm for quite some time but recently while riding it the gear box seized up in 6th gear and left me stranded, needed to be picked up . when we got it home, we managed to get it back to nuetral and it started and rode around in first gear, to get to second gear and there up was a struggle. since then we have dropped oil through it (it was slightly matallicly) a few times and it has freed it up more. if any one has any info about the problem, parts, or links it would be very much appreciated. we have a machenic that can do the work but hasnt been able to look at it yet he also mentioned that the gear box may be a cassette style?? (put in, pull out). thanks, chappy.