Hi to all, Through unfortunate circumstances I have inherited my brothers NSR250se mc21 and will be doing a ground up rebuild to track spec for track days and possibly some club racing. I have pretty much had dirt bikes or road bikes since I was a kid however its been over six years since Ive not had a single bike in the garage! Anyway this rebuild project has got the two stroke coursing through my veins again. I am currently gathering as much info about the nsr250 before I start, so looking forward to meeting any other nsr owners out there. Cheers Eddy
welcome Fasteddy, we have a few SE Qld NSR owners , some of whom hit the track quite regularly. feel free to start a project thread @Brizfox @Nathan Oliver @Duggs63 @KICKERMAN360 @Fox McScrooge
Welcome! If you need spares let me know. I have mostly MC18 things, but some MC21 stuff. My NSR project is glacially slow but getting there. Hopefully your bike rolls under it's own power sooner rather than later.
Welcome. I currently have 2 , an R and an SE. There a super quick 2 banger with all the electronics they had on them in the day, however the crank is the achilles heel.
Yeah I found out they aint cheap but you can still buy new ones through tyga or have the crank rebuilt. From what I have read the guys at nsrworld in the uk are the go to guys for crank rebuilds unless you guys know of anyone here in aus that could rebuild my crank
Hi Eddy. Happy to help in any way. I have a set of Koyo bearings (which are the stock bearings on the NSR crank) and Honda seals for my back up crank that I bought from Tyga. Haven't had much joy finding someone in Aus to rebuild it though. NSR-World rebuild is pretty expensive. They do however have a good supply of parts including the thrust washers which are virtually impossible to get your hands on. Once you pay postage and covert to pounds sterling I reckon you're almost better off just buying a brand new crank from Tyga. Like Brizfox said, the crank is definitely the worry with the NSR. No guarantee how long Honda will continue making them. Makes me think about RGV more and more but the Honda is a great bike.
To extend Scrooge's thoughts, Honda really aren't too keen on supporting the older 2 strokes much, or even their last gen 2 stroke CRs. So Whilst my bikes have always been Honda, unfortunately for them my next bike looks to be a KTM and if I were to purchase a 2 stroke road bike it would be an Aprillia RS250. Shame really since the NSR is a pretty awesome bike.
Welcome @fasteddy Good to see another NSR being brought back from the dead. Get a project thread up ASAP so we can all have a look-see. Cheers,
Greame Selwood did a crank for me . He's now in Darwin. The centre bearings the difficult one as was a Honda one off make. The 2 outer bearings are off the shelf but all have to be C 3 rated. Should get 10 k out of a center bearing depending how its riden. The MC 16 is a better version as it has a separate center seal which was like all the other makers of that era.
That's the guy I've been trying to get to do mine Briz bit he keeps telling me I have the wrong bearings. Despite the fact I bought them from Tyga. Despite the fact a Koyo rep sent me emails confirming they are the correct C3 rated bearings. Did you get yours from Tyga?
Thanks for all the info guys, its really appreciated. I know some of you are saying it might just be better (cost effective) to look at a different bike to take to the track to get back into racing but there are a few reasons why I am going to pursue the rebuild of this bike. A few quick points I would like to make as to why I plan to rebuild this nsr, 1. This particular nsr250 is my brothers old race bike 2. We used to race together in the early to mid 90's, I raced an rgv vj22 3. My younger brother passed away to cancer before he got the chance to rebuild his beloved nsr. He was looking to get back on the track. It is for these reasons I want to revive his bike to the specs he was looking at and put it back on the track where it belongs. I want to use it for track days and hopefully race in some sort of club series. I know if I was a bit more serious about racing I should probably go for something like a 600 but this is not about my wants, its about fulfilling my brothers wishes to get his bike back on the track and thats what I plan to do. I am by no means looking to set any records, those days are long gone! i just want to see his bike back on the track the way he envisioned. My profile pics is actually my brother on his nsr on one of the first track days he ever did. Thanks again for all the input. I will start a build thread shortly. The bike is still in Syd at my parents place, I will be driving down to collect it on the May long weekend and hope to start the rebuild once I have it safely in my workshop. Regarding GT performace (nsrworld guys) Andy has sent me some pricing and yes although its not cheap its not what I would call ridiculous either. So once the engine is stripped and checked I will send the cases, crank, barrels and heads to them for some work. In addition I plan to buy a new crank, pistons, rings and gaskets to build a good spares kit to keep the bike going for years to come. Thanks again to all for your help.
A noble project mate. I wasn't trying to discourage you. They are great bikes and there are plenty of parts available from places like Yahoo Japan. I have had RGVs and I think you'll be very happy with the NSR handling by comparison. If you want the best out of it you'll need to do the wire splice and get it breathing better with a better airbox or open carbies. You'll also need HRC parts for the carbies which are basically a set of three different adjustable needles with different tapers and HRC air jets. Stock needles are non adjustable. With the stock air jets it runs too lean in the midrange. I found carb parts on Yahoo Japan. With the MC21 you should get 60hp plus just with those changes. Although heavy the 21 exhaust already breathes well. To get even more power you need to look at porting the barrels and flowing the cases but it sounds like Andy has you sorted. Then there are F3 parts like different carbies, close ratio gearbox, lighter flywheel etc. There are other options for the barrels. Millennium Engineering in the states for replating for example. MC28 is harder to get power from. I had my barrels done by Millennium. Replated, ports matched and exhaust ports flowed. Tyga airbox, reedblock, exhaust manifolds and exhaust. That with HRC card and HRC carb parts and it's putting out low 60s which is pretty good for a 28. Good luck with the build.
Really love that bike and its pretty rare now a days. Do keep us updated with the work! Welcome by the way.
