Very easy to rebuild. Like a big whipper snipper haha. Thay come under the restrictions because they come limited to 45hp from japan. Get on NSR.com which shows how to take the restrictor of with one simple wire job for instant 65hp. Makes it the same as a aprillia rs250/susuki rgv. Infact mine used to pull away from a mates 03 rs 250.

why were the nsr250's restricted? i know they now comply with the power to weight but when they were released it woulda just been under 260cc. how often does it need to be rebuilt and does it just need top-ends or full rebuilds? sorry for all the questions but i'm trying to get as much info as i can. thanks

NSRs are all grey imports and were restricted from 89 onwards. MC18 and up as they came from japan. Story goes too many accidents were happening on the early unrestricted model the MC16(pre 89). Top ends are as good as up 40000km if synthetic has been used its whole life and the bottom is good for 60000km before the bearings even need a look. To be safe you'd prob do the rings every 15-20k to keep it all fresh. For more peace of mind they are based straight from the NSR250 GP bikes and are strong as hell.

i have one of those, very nice bikes, but as freak mentioned they are grey imports and thus hard to find parts for(in sa anyway)

just bkeep an eye on the cooling system,use a toggle for the fan if you have to..

im buying a rvf400 might sel the datsun dunno think my motor blew up tonight