CB400SF Cam chain Tensioner

[Chaoschild]

Hi to All,

this is my first post here and I'm asking for help right away. I have a CB400SF Project big 1. The engine code starts with NC23E, but on the frame it says NC31. It is registered as NC31. As the bike has never been available in Hungary it was hard even to register it. I think the bike is from '92 or '93. The first registration happened in 1999 but the bike is absolutely from before '99.
Anyway the bike has been diong a great job in the past years and I intend to keep it. But the cam chain recently started rattling. We have checked and the chain is okay. But there were pieces of "grinded" plastic around it. As far as I could find out they must have fallen off the cam chain tensioner. So the tensioner does not do it's job anymore.

My question is if you could advice me on how to find a replacement. I do not know the article/part number so it is hard to search for it. The CB400SF is barely known in Hungary so there is no hope to get it here. I searched the ebay without luck.

Is there any other bikes where the system is the same so I could just replace the tensioner with one from another bike?

Any help would be appreciated.

Many thanks in advance and Best Regards,
Csanad (Chaoschild)

[Ropehead]

Hi. I have a project Big 1, '92 that i ride and another 400sf in bits from '95. Im am rebuilding this to learn more about
the bike i run so only a beginner but hope i can help. You have the cam chain tensioner and you also have two plastic
guides inside the engine for the chain, one to the front of the engine and one to the rear. Im not saying it is but it maybe one of those where the grinded plastic is coming from rather than tensioner it self.

Have you had a look at these ?

Someone more in the know may correct that if Im wrong, as said only a beginner.

There is a parts manual posted in the documents libray for cb400 superfours that might help you to find part number.
I also have a parts list covering '92 to '98 which is a couple more models than one listed. Both include a guide to engine and frame numbers to determine what model you have and the part number for what you need.It is in japanese but numbers and pictures have worked fine for me during my rebuild.As soon as i have worked out how I will get the file posted in the documents library so hopefully one of them will help .

Happy biking, hope this is of help.

[Chaoschild]

Hi Ropehead,

many thanks for the reply. This weekend I will take the thing apart and check.
I'll lok at the guide to see if it is the faulty piece.

Thanks very much and Best Regards,
Chaos