Hudtm60 wrote:
PE said they would like pictures of my crank before they would commit to working on it- I think it's because two kinds of cranks were installed in the MC18 and they need to know which one, but I haven't got to splitting the cases yet. Paul @ Tyga said that the earlier later MC18 cranks share bearings with the MC21 and MC28 which they sell.

I contacted PJME of Wolverhampton today. I purchased a crank from them for my RD350LC, it's the smoothest running bike I have right now, but they won't do it because they are sure the parts are unavailable.

Not sure which crank I have but if it's an early one PJME recommended Chris Applebee Engineering who can recondition the parts already in the crank....hmm. http://www.applebee.co.uk/

There's nothing that can be reconditioned. If anything [other than the thrust washers] is beyond tolerance, the crank is scrap. Any pitting on either of the big-end pins, and the crank is scrap. Any pitting or wear on conrod big-eng/small-end bearing face, or thrust washer faces, and the rod(s) will need replacing. OEM rods are not available for purchase, although I believe there may be an aftermarket alternative available now.* The NSR crank is extremely compact; consequently the big end pins are integral to the crankwheels, and therefore cannot be pressed out and replaced as you can do with many other 2-strokes. It was designed as a consumable item, which was fine at the time, but now MC16 and MC18 cranks are discontinued, it's a bit of a bugger! GTPE ask for high quality, detailed photos from potential clients from abroad, to try and mitigate unnecessary costs as much as possible. If damage can be seen or anything is remotely questionable, they will advise that it's probably cost prohibitive to send them the crank.

*GTPE will only use OEM/genuine Honda parts for the NSRs. They won't use Mitaka pistons, aftermarket conrods, pattern gaskets etc. They're expensive, but you're paying for one of the best in the business. I've heard PJME Yamaha and Kawasaki cranks are very good, and I've also heard good reports about Chris Applebee, however only GTPE solely specialise in Hondas. If I was going to take a Honda crank anywhere else in the UK, it would be to Andrew Sawford at St. Neots Motorcycles (Two Stroke GP Restorations on Facebook).

The 1988 R2/4J crank is similar to the MC16 (and RS250R NF5), with an independent centre seal. The R5/6K crank is similar to the MC21/MC28 crank, with a centre seal integrated into the centre main bearing. You already confirmed your engine cases are 1988 at the beginning of this thread. There's a small degree of interchangeability between 87 & 88, and 89~96, but it's not just a case of swapping cranks if you can only find the "wrong" replacement. Only the MC21 and MC28 cranks are truly interchangeable without any additional work.

All cranks use the same bearings, although the 87-88 use a different combination of bearings to the 89-96. (The 89-96 has a unique centre bearing. All main bearings these days are readily available.)

Finally, you won't find a more experience NSR crank builder in the UK than Steve at GTPE, but as Eric says, the cost can potentially be prohibitive, mainly down to shipping. It never stopped us doing cranks and full motors [while I was there] from literally all over the world though. We even did cranks and motors for Japan in the early days, although they are well catered for again now [10 years on].

As a side note, we found everything can be temporarily imported and then exported back to origin without taxes if documented properly, as it's a reconditioning/restoration service.
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Andy.
NSR-WORLD.COM

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