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'75 CB500T - a work in progress ; '74 CB750
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Discussion Starter · #1 ·
Hi guys,

Wondering if there's a way that I can adjust valve clearance without breaking the cam chain and cracking the top off of things?
I've got the timing set quite closely and well according to the pinned post and the HONDA manual.
I have ZERO compression on the LEFT side so think the valves aren't closing properly.
Or possibly a bent valve i guess (but hope NOT).

Thanks in advance.
 

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If you have the Honda manual, the valve adjustment procedure is in it. You pull the valve covers (the rectangular covers on the front and back of the cylinder head with 8 bolts in each) and the 3 screw alternator cover so you can turn the crankshaft, rotate the engine to TDC on compression stroke for each cylinder and adjust the eccentric follower shafts to set the clearance between the follower and cam lobe at .002" for both intake and exhaust valves with the engine cold from overnight. If you have zero compression on one cylinder, it's unlikely a valve adjustment will cure it.
 

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'75 CB500T - a work in progress ; '74 CB750
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Discussion Starter · #3 ·
Yeah the valve adjustment didn't help at all. I was hoping i wouldn't have to open things all the way.
A work around really.

Any tips for opening up the top end? Besides not dropping the cam chain into it.
 

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Remove the tappet covers and watch the rocker arms while you turn the engine over, see if they both appear to rise and fall the same amount.
 

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Discussion Starter · #5 ·
Hi guys , just giving a bit of a bump here.
My chain breaker took a very long time to arrive + xmas + a very cold snap and non heated garage has slowed things.
I'm going to measure as best i can the travel of the valves. But seems like the fix is to pull the valves and god from there - thinking one may be bent and not seating/closing completely.
 

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Discussion Starter · #6 ·
I was able to confirm using a strong flashlight that the left intake valve is not closing completely.
Is there a method where i can adjust the tappet and valve without breaking the cam chain and pulling everything?

Hopeful.
 

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You might check the torsion bar valve spring to see if it has a problem before taking things apart.
 
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Discussion Starter · #8 · (Edited)
Thanks Mike.
Any tips on how to do that?
It all seems to move freely and properly, besides not closing.
 
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