Camshaft removal - valve clearances (shim under bucket)

[B0ndy]

Hello all,

I'm currently working on checking and swapping out the shims on my CB400 Superfour but am stuck/unsure on the camshaft removal.

I've never needed to remove a camshaft from an engine to make adjustments to the valve clearances before and the warning in my Haynes manual about the job being not for a DIY mechanic makes me more worried about it than I probably should be.

I can't find much on the net about the general procedure, I understand that it will vary from bike to bike but does anyone have links to any good guides on the topic?

Also, should I take notice of the warning in the manual and hand the bike over to the professionals instead of attempting this myself?

Thanks
Mbond
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CBF 125 -> CB400SF -> GSX600F -> ZX6R (G1) -> GSXR1000 K4 -> ZX6R (B1H Stunt bike) -> VFR800 -> R1 5PW -> Sprint 1050 -> Fireblade 929 -> ZX10R C2H -> GSXR1000 K3

[monkeybiker]

Chain tensioner should be removed first.
You have to loosen each bolt a little at a time so it comes off evenly.
This pic is for tightening so to loosen start with no:10 and work back. Loosen each bolt little by little.
Your haynes manual should have a description and picture.

Once you have cams off take out one bucket at a time and measure the shim make a note of it and then put it back in it's place so you don't mix them up.

Take your time

When you put it all back together make sure the chain timing is correct and re-check valve clearance. Don't start the bike until you are 100% happy all is correct.

[Pigeon]

Seems odd that Haynes warns against it. What is so special about a cb400?

Shim under bucket is not exactly limited in its use across engines.

So does the Haynes manual actually spell out the procedure?

Also, can you download the official Honda service manual from anywhere? Sometimes its good to have two explanations of the same thing......sometimes its more confusing

[B0ndy]

Thank you both.

[A100man]

My tip make sure you know how to set your torque wrench. It can be easy to set them 5 or even 10 ft/lbs higher that you need - which is a lot on a cam cap that's probably only M6 8 ft/lbs..

.. still I now know how to helicoil..

J
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Now: A100, GT250A, XJ598, FZ750

Then: Fizz, RS200, KL250, XJ550, Laverda Alpina, XJ600, FZS600

[FlightRisk]

[Fizzer Thou]

Is the cam chain drive in the centre of the cam or on one side?

The reason I ask is because with one you can virtually leave the cams connected to the cam chain,but with the other it is better to completely remove the cams.

https://i666.photobucket.com/albums/vv23/WiNot_Rhencullen/Workshop/Picture361.jpg
https://i666.photobucket.com/albums/vv23/WiNot_Rhencullen/Workshop/Picture366.jpg

But say the inlet valve clearances are okay,you can leave that one in situ and just deal with those clearances that need doing.

https://i1073.photobucket.com/albums/w384/Rhencullen5/Picture079.jpg

I had some thoughts when I first needed to do the shims on my Exup 1000.But with plenty of preperation and copious note taking,I was able to complete the work okay.The sound of the engine running once everything was rebuilt is better than my favourite music
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Always have a 'Plan B'

[mentalboy]

My

As well as using a piece of wire to prevent your cam chain disappearing into the guts, stuff every orifice with non-shedding cloth. Fishing a nut from the guts is not nearly as easy as preventing it getting there in the first place.

[Fizzer Thou]

Agree with Mentalboys comment.There is nothing worse than dropping a component down into an inaccessible place.So stuff holes with anything useful

https://i666.photobucket.com/albums/vv23/WiNot_Rhencullen/Workshop/Picture368.jpg
____________________
Just talk bikes.What else is there?

Always have a 'Plan B'