Hi all
Would anyone know or have the part numbers for R2J or R4J crankshaft seals and bearings.
especially the centre seal.
I have found a good engineer here in NZ that can service the crank but finding the parts is a real mission.
local honda agent tells me if they have the part numbers they might be able to track the seals down,but they cant trace the model of the bike as their parts data system does not go back that far.
welcome any help please.
Owen

Aren't those on sheet E-10 of the NSR250R2J/R4J [R5K/R5K-2] 88/89 in the Online Parts Manual of nsr-world.com?
At least the l/h and r/h seals are there, as far as I understanding there are no Honda part numbers for the bearings and the centre seal themselves because Honda considers the crankshaft not to be servicable.

There are no official Honda part numbers for the NSR250 main bearings or R2/4J centre seal. A read of the VERY recent crank-related topics would've told you this.

We re-use the centre seals in our rebuilt 87~88 and RS cranks, when it is safe to do so, and the customer is advised of this.
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Andy.
NSR-WORLD.COM

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Hi Owen;

Its a difficult pill to swallow but yes did a leak down test yesterday on my mc 18 and centre seal is, lets say leaking like a tub without a plug in it. For me it is beyond my comprehension that Honda will allow this . I have rz 500 rz 350 tzr 250 3ma 1kt and 3xv get the cranks done in the snap of a finger parts available if not from Yamaha, yambits has it. My crank is now a paper weight well if I press it apart 3 paper weights . But I vow this I will find a way to make it work maybe suzukii has a seal for me . I will press it apart and find a seal to make it work may not be this year but I will get their.

Fact is in the next 30 years no more Honda mc 18 twostroke';s around. I will have to display it as a model of how the bike once looked Sad thing is this bike actually is the one bike that disciplines all the other twostrokes out their it goes like a rocket ship 3ma doesn't come close. My 3ma track bike is still going at least so I can not complain to much oh yes rebuild the crank last year .

Sorry for the complaining I just think we need to do something about this lets get the Hondas running into the future I still want to race my mc 18 in 30 years time.

Edd

Understand your grievances, Edd. We're in the same boat!

We have a centre seal manufacturer, but they won't guarantee the seal to 10,000rpm, let alone 12k and beyond, like the OEM Honda one. The problem is the Honda seals have a special second coating on them, making them more resilient to high RPM.

I'm sure back in 1988 there were thousands of spare MC18 cranks, and probably at only 1/3 of today's prices of a new MC28 item. Sad thing is everything has an "end of life" with manufacturers, it just seems Honda are a bit more callous about it than most.

We've looked at machining the crank to take a more conventional seal size, but the problem is losing the hardness properties once you cut into it.
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Andy.
NSR-WORLD.COM

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Well done Edd and i agree something needs to be done about these ghost seals as i like to call them,ie now and again they appear for sale then disappear into the eyther of time and space .
The thing is what to do?. I am sure that someone somewhere has a big heap of them.
Myself i now have someone here in NZ that has the experience to service this type of crankshaft,now all i need to do is find a company that will maufacture the seals. when i find one i will let you know .
thank you all for the information and help.

Hi Gents;

Will strip the crank as soon as I have the necessary spaces made to press at 90 degrees. Once I have the seal in hand I will have a look at a replacement seal. Maybe I must fit one of the replacement seals andy is talking about and give it a go. How do I get hold of one of those replacement seals.

Edd