Author Topic: Valve cover/rocker arm question  (Read 1465 times)

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Offline Scott S

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Valve cover/rocker arm question
« on: March 25, 2012, 05:08:54 AM »
 Bike is a '78 CB550K.

 I recently pulled the top end on this bike (head and cylinders). This was my first time removing a head and I mistakenly removed these four nuts, thinking they were some of the ones that held on the head.



 Realized my mistake and put them back on. However, when I was cleaning up the valve cover yesterday I noticed something that seemed a little odd....
'71 CB500 K0
'17 Triumph Street Scrambler
'81 Yamaha XS650

Offline Scott S

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Re: Valve cover/rocker arm question
« Reply #1 on: March 25, 2012, 05:12:18 AM »
 I noticed that when the rocker arms are at rest, they're not all even.
 With the valve cover upside down and the arms resting on the tappet cover holes, the arms are at varying angles.

 The only tool I've used to measure them is my eyes, but the exhaust side seems fairly even all the way acroos. The intakes are all different from one another.

'71 CB500 K0
'17 Triumph Street Scrambler
'81 Yamaha XS650

Offline Scott S

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Re: Valve cover/rocker arm question
« Reply #2 on: March 25, 2012, 05:16:21 AM »
 This view shows what I'm talking about a little better.




 I also noticed that these.....plugs, or whatever they are. Aren't even. I take it that they're the other end of the threaded stud under the breather cover; the ones I removed the nuts from.
 This side seems flush:


 And this side seems countersunk:


 Did I get something out of adjustment when I removed the nuts from the studs that lock the rocker arm shafts into place? Do you adjust anything in there to even up the rocker arms? Does it matter?
'71 CB500 K0
'17 Triumph Street Scrambler
'81 Yamaha XS650

Offline thrutheframe

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  • did you bleed when you built that?
Re: Valve cover/rocker arm question
« Reply #3 on: March 25, 2012, 06:13:46 AM »
+1 I wanna know.
'74 cb 750 K4
'79 CB 650 http://forums.sohc4.net/index.php?topic=83981.0
'75 CB 360T
'90 RC31 Hawk GT

Offline MRieck

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Re: Valve cover/rocker arm question
« Reply #4 on: March 25, 2012, 06:26:41 AM »
Those 4 nuts secure wedges that hold the rocker arm shafts in place. They are wedged in very tightly. I have to put the cover in a shop press and push them (force applied to the threaded  top of the wedge). You have to remove them to get the shafts out. The chrome is gone on several of your arms. New ones are not available from Honda or anybody else. You have to hardweld them...I can have that done for you if you like.
Owner of the "Million Dollar CB"

Offline Scott S

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Re: Valve cover/rocker arm question
« Reply #5 on: March 25, 2012, 06:30:28 AM »
 So, what about the arms all being at different angles at rest?
'71 CB500 K0
'17 Triumph Street Scrambler
'81 Yamaha XS650

Offline thrutheframe

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Valve cover/rocker arm question
« Reply #6 on: March 25, 2012, 07:21:14 AM »
So, what about the arms all being at different angles at rest?

Are you referring to the heights? Or do you feel like they are off left to right?  I can't see it. 
'74 cb 750 K4
'79 CB 650 http://forums.sohc4.net/index.php?topic=83981.0
'75 CB 360T
'90 RC31 Hawk GT

Offline Scott S

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Re: Valve cover/rocker arm question
« Reply #7 on: March 25, 2012, 07:37:04 AM »
 The height.
'71 CB500 K0
'17 Triumph Street Scrambler
'81 Yamaha XS650

Offline MRieck

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Re: Valve cover/rocker arm question
« Reply #8 on: March 25, 2012, 08:43:18 AM »
Nothing to worry about at all as long as they all move freely....that's what happens when the cover is removed and the rockers are not under valve spring pressure.
Owner of the "Million Dollar CB"