JasonM wrote:
1. How easy is it to source a crank and which models are interchangeable?
2. Roughly how much would I expect to pay for one?
3. Who are the experts in rebuilding them in the UK?
4. Whats not available for the bike or easy to source in general?

Hello Jason, and welcome to NSR-WORLD.

So, in the order they were posted:

1. Not very easy. R5/6K cranks are long discontinued, and no other crank is directly interchangeable. It is possible to machine the later MC21/MC28 crank to fit though. But finding someone to do the job properly may be difficult. While they can be rebuilt, they're not officially rebuildable, so not all the parts are either available, or replaceable. This means that any used crank you source does run the risk of being fit for nothing more than the scrap pile, and you won't actually know until it's split and inspected. GT Performance Engineering will inspect a crank for £25. Steve at GTPE could machine a new MC28 crank (currently running about £650), but whether he will or not is another matter. You'd have to call and ask... very nicely!
   
   
2. As with #1, a new MC28 crank is about £650 now, and would need further machining to fit MC18 R5/6K cases. A freshly rebuilt MC18 R5/6K crank is probably going to stand you in between £300 and £500, depending on how benevolent the seller is feeling. Expect closer to £500 for a rebuilt MC18 crank, and less for a machined & rebuilt MC21 crank. A dead crank, for rebuild, could be anywhere from £50 to £250 in my experience.
   
   
3. Unquestionably, GT Performance Engineering in Plymouth are the UK's only true NSR250 specialist. If I were to take an NSR anywhere else, it would be to Andy Sawford at St. Neots, but he's an HRC RS (and Yamaha TZ) specialist, and while they share very similar DNA, I am sure Andy is professional enough to admit himself you would be better off with someone who knows the NSR250 inside out -- and Steve at GTPE does. Andy Sawford however, would certainly be more than capable of rebuilding the crankshaft to exceptional standards, as the NSR250 crank is extremely similar to the early HRC RS250 crank.
   
   
4. TYGA Performance are your best bet for any aftermarket parts, and David Silver and CMSNL for NOS Honda parts. Most, if not all, the internal engine parts (except the aforementioned crankshaft) are available, but things like barrels and heads are no more. They can often be sourced on Yahoo! Auctions in Japan, and sometimes on eBay, or even through classifieds on this site.

Once up and running, people don't seem to have any problems keeping them on the road still. Also, the simplicity and performance over any of it's contemporaries will more than make up for any initial inconvenience and expense!

Hope that helps, and please keep us posted.
_________________
Andy.
NSR-WORLD.COM

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