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Author Topic: CB450 K6 valve adjustment question  (Read 2225 times)

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Offline zoo mob

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CB450 K6 valve adjustment question
« on: July 05, 2010, 01:45:56 PM »
Pretty sure I get how to do this procedure, but I'm a little confused as to how to figure out whether you should be adjust the exhaust or intake valve on a given side when the mark is lined up. With the SOHCs, you can just wiggle the follower (or whatever its called) to know which to adjust, there does not seem to be similar play in my 450, but there is definitely some valve noise I'd like to correct.
Andrew
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Offline Old Scrambler

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Re: CB450 K6 valve adjustment question
« Reply #1 on: July 08, 2010, 11:47:34 AM »
If I remember correctly............on the mark #1 intake and #2 exhaust and then rotate 360. Its been 44 years!  If your valve covers are discolored from heat, its usually a sign that a bearing is gone bad from lack of oil......resulting in loud and non-adjustable lash.
Dennis in Wisconsin
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Offline tbpmusic

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Re: CB450 K6 valve adjustment question
« Reply #2 on: July 08, 2010, 01:49:25 PM »
Rotate the engine with the alternator bolt until the LT mark lines up, with the left side on compression stroke.

Adjust both left side valves to 0.002"

Turn the alternator 180 degrees counter-clockwise till the T  mark lines up - now the right side is on compression stroke.
Adjust both right side valves to 0.002".
« Last Edit: July 08, 2010, 01:52:13 PM by tbpmusic »
"If you can't fix it with a hammer, then it's an electrical problem"

Bill Lane
 '71 CB450 Mutant/ '75 CB200/ '81 CM200/ '71 C70M/ '72 CL350
http://home.comcast.net/~tbpmusic3/450site.htm

Offline Old Scrambler

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Re: CB450 K6 valve adjustment question
« Reply #3 on: July 09, 2010, 11:09:46 AM »
I defer to the music man and appreciate the info.............
Dennis in Wisconsin
'64 Triumph Cub Bonneville Salt Flats AMA Record Holder
'63 CL72 Project(s)
'66 CL77 Red
'67 Triumph T100C
'73 750K3 Owned since New
'77 750F2 Cafe Project
2000 Aprilia Pegasso

bobjohnson

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Re: CB450 K6 valve adjustment question
« Reply #4 on: July 13, 2010, 01:52:26 PM »
The T mark will line up both at TDC on compression and exhaust stroke though. I found the easiest way on the 450 is to just do each valve seperately, turn the crank until the cam lobe points straight up, and then adjust. There are other marks on the camshaft you can look at to see if its at TDC on compression but on my bike they werent there (should be an index mark on the cam that lines up with a score mark on the head, the mark on my cam didnt exist).

Also remember on the adjusters, the index mark needs to face OUT from the motor. If you turn it far enough around that the index mark points towards the center of the engine, you can get the clearance right but the cams wont open the valves properly.

I also like to set my clearance to 0.04mm which is 0.0015" (0.03mm is the honda recommended clearance).

Offline tbpmusic

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Re: CB450 K6 valve adjustment question
« Reply #5 on: July 13, 2010, 02:34:40 PM »
The T mark will line up both at TDC on compression and exhaust stroke though. I found the easiest way on the 450 is to just do each valve seperately, turn the crank until the cam lobe points straight up, and then adjust. There are other marks on the camshaft you can look at to see if its at TDC on compression but on my bike they werent there (should be an index mark on the cam that lines up with a score mark on the head, the mark on my cam didnt exist).

Also remember on the adjusters, the index mark needs to face OUT from the motor. If you turn it far enough around that the index mark points towards the center of the engine, you can get the clearance right but the cams wont open the valves properly.

I also like to set my clearance to 0.04mm which is 0.0015" (0.03mm is the honda recommended clearance).


The cam marks will not line up on compression stroke. Cam timing on a 450 is performed on the "off" stroke - this is to help keep the alternator stable while hooking up the cam chain, allowing one person to do the job.

Valve adjustment and ignition timing are performed on the compression stroke. But the cam marks will not line up in that position.........
"If you can't fix it with a hammer, then it's an electrical problem"

Bill Lane
 '71 CB450 Mutant/ '75 CB200/ '81 CM200/ '71 C70M/ '72 CL350
http://home.comcast.net/~tbpmusic3/450site.htm

bobjohnson

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Re: CB450 K6 valve adjustment question
« Reply #6 on: July 14, 2010, 01:27:26 PM »
Just going by what the clymers manual says (which is proven to be crap when it comes to valve adjustment). The honda manual actually just says "Line up the T Mark with the left cylinder at TDC". It doesnt explain how to tell if its there. On my old bike, i used the straw trick, but with the 450 since i can see the cam lobes, i find it easier to do each one seperately. Also saves wasted time when the bike rolls itself over TDC while youre trying align the T mark.

 

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