Topic: CB400F unknown metal part in oil pan

[puddle pirate]

Evening Gentlemen,  I have haunted this site for quite a while and recently purchased a badly treated 75 CB400F.  I have not decided if I'm going to rebuild it or part it out yet.  I have taken a bunch of photo's as I began going over in hopes of posting them if i decided to do a build.  Anyways pulled the oil pan to clean the sludge out and check the screen before i added new oil and rebuilt the carbs to try and start her.  She has good compression, turns over with both the kick start and starter and has no odd sounds that i can tell.  This was in the bottom of the pan along with a very small amount of gasket material that was stuck in the pump screen.  I have no idea what it is or what it goes to.  The grooves tell me that it might have rubbed on the cam chain or something?  If someone knows i would really appreciate it.  I was hoping that i would not have to really mess with the engine that much.






I Know that one is a quarter, so thanks
JT

[Bodi]

definitely the end of a cam chain tensioner blade.

[Hush]

That looks like the bottom part of the cam chain tensioner system, it is complete from what I can see.
It fits right down in the bottom of the big end area, well according to my parts diagram anyway.
Looks like it has just come lose and fallen out, I predict a motor teardown in your future.

[bryanj]

Either the cam chain tensioner blade or the cam chain guide has broken and that engine needs removing, stripping and giving a dose of extreeme car NOW or VERY expensive things will happen

[Kwality]

Like those good folks above - that is a part of your cam chain guide blade which is part of the tenisoning system.... but it isn't complete.  Whole ones look like this:

(guide blade)



Fixing this up is going to be a b!tch.  Sorry.

[puddle pirate]

Thank you all, I was afraid thats what it was.  That $22 part is going to be a pain to get to. 

JT

[Bodi]

You can get at it with engine in frame. The main frame tube is directly above the area so access is difficult but it's possible to service the slipper and tensioner this way. You'll need a small mirror to see down the camchain tunnel.

[Hush]

Does that metal strip go right through the length of the cam chain slipper?
If so then it has snapped off, is that possible?

[Kwality]

Could it happen if the cam chains is so loose it rubs and rubs and, well,  rubs?  Seems extreme.

[KingCustomCycles.com]

Like not adjusting the chain since it was built?  That was a big issue with the DOHC later on.  The loose, poorly maintained, chain would wear right through the front of the engine block and blow oil everywhere.  Many of those have JB weld patches hanging off the front.

[camelman]

That is a concern, but it isn't all that bad..,maybe. Pull your valve cover and remove the guides you have access to. If they are complete, then definitely pull the engine to look for other parts since the rest of that guide might still be in there. If it is obvious that only one guide is missing that exact piece, then you might be okay to run it. I would be concerned that a PO might have caused other issues though, so I'd look through the entire engine/trans.

Camelman

[bryanj]

400 tensioner mechanisms are notorious for getting tight on the pivots when the chain hits them and that is a bottom off full stripdown---even if your tensioners are intact it means that the job has not been done right before------bite the bullet take it out strip it right down and re-build it properly so you can have confidence in it running right

[Hush]

Dang looks like Honda also invented the vertical chainsaw!