Hello everyone,


Friend of mine is restoring an MC16 and got stuck on the centre crankshaft seal which has to be replaced. It seems like it's no longer manufactured by Honda and we cannot find it anywhere online.

I proposed to help him search for a solution.

So, here I am. Can anyone help him with that?

He wants to keep the bike to be original so a replacement engine is out of the question.


Thanks in advance,
Zurgel

You can source them from Tyga directly
https://tyga-performance.com/advanced_search_result.php?keywords=TPER-5007

Or from Tyga in Europe
https://tygaeurope.com/product/crankshaft-seal-centre-mc16-and-mc18-r2j-r4j-2/?srsltid=AfmBOoptL-3OjvNyNmTXBdC2IvygWlQRbFIeDBUSFOaLPGf77QvFX8Ce

The crankshaft will need to be pressed apart and back together by someone who knows what they are doing. It would be wise to consider replacing the bearings as well while its apart.

Welcome to NSR-WORLD, Zurgel.

You will have to replace the main bearings when the crank is split, as they will be damaged when removing them. Usually, not always though, the big-end bearings will be fine. As Eric says, the crank should be built buy someone with good experience, particularly with NSR and RS cranks, as the components are not indexed, and will need assembling very carefully.

Please keep us updated on your progress.
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Andy.
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Thank You Eric and Andy for your quick response.

I forgot to mention the bike is from the first type of the MC16(1986).

I already found out that there are two types of the MC16, where the second type has a bigger shaft in the middle of the crankshaft. So, the links to the seals Eric mentioned will not fit. The shaft in the middle of the crankshaft of the type 1 MC16 is 45mm.

The type of seal we are looking for is a FAJ8 45x68x5,5 GS, the (de)mounted brand is Ats.

The Crankshaft is already pressed apart. And ofcourse all bearings will be replaced. I think the mechanic who is restoring the engine knows what he is doing.

Kind regards,
Zurgel

This might sound a bit bonkers, but did you "test" the seal before you disassembled the motor? The reason I ask, is that they are almost always good to use again. I know it's not ideal, but all of the MC16s we have done over the years, they have all reused the centre seal due to the lack of available replacement. MC18s too, until T2 started reproducing seals.

I can't guarantee it, but it's almost certainly OK to use again. If the seal is for some reason worn or damaged, personally, I wouldn't think twice of buying a cheap used MC16 crank and salvaging the seal from it. The chances of getting two duff MC16 seals is extremely remote in my experience.
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Andy.
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Last edited by Andy on Sat Nov 08, 2025 2:38 pm; edited 1 time in total

Hi Andy,

The NSR is not mine and I have never seen it. I have listened to his story about the seal they can't find and I proposed him to try to find a solution so he can use the bike where it's build for.

I have asked him several questions regarding to your thoughts.

Thank you for share your information, I appreciate it.

By the way, it's not that I am not interested in his NSR. I like 2-strokes also and like to have one once. Too many hobby's maybe .

Regards,
Jurgen

Regarding the previous post I have more infornation

The original seal had hardened and also had space around the shaft. So it was no longer useable unfortunately.

The solution might be an alternative with a different seal, but that will not be tomorrow i'm afraid.

Thanks all For your input.

Regards,
Jurgen

Yeah, that's unfortunate. As I say, we've re-used them many times, so if he can source an "OK" crank, it's highly likely the seal can be salvaged.
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Andy.
NSR-WORLD.COM

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