Topic: Question about a 1978 CB750 engine

[lucky]

I am putting new valve guide seals in my cylinder head.
When I was putting the engine in position to remove the cam (which I did not have to do BTW). I did not have to remove the cam to install new valve guide seals.

I noticed that when the engine is on the 1-4 T mark that number one cylinder did not have the cam in the right position even though the NOTCH on the end of the cam was pointing at 12 o'clock like it was supposed to be to take the cylinder head apart.

I thought the engine had to be with No. 1 piston TDC, and cam in position for valve adjustment. Cam lobes facing down at 45º. But then the cam NOTCH is facing down NOT upwards for cam removal.

Is that right?


Because most engines want piston at TDC Compression stroke, for valve adjustment AND engine teardown.

[lucky]

No one knows anything about this?

[lucky]

I will try again.

The honda workshop manual says to remove the cam and top end that the crank needs to be on the 1-4T mark. OK...
And the notch (looks like a woodruff key slot in the end of the cam, facing up 12 o'clock position. But then the no#1 cylinder valves are not in the position that you would set the valve clearances at. Instead of the lobes for intake and exhaust facing downwards at 45º angles, the lobes are facing up at 45º angles on this stock engine. Not in position for valve adjustment. Is this to get the full slack of the cam chain?

So engine disassembly is TDC#1  and valves on overlap - not in a position for setting clearances. Just seems like they should be but if I turn the engine over one more time the valves are in position for setting clearances( lobes on #1 facing down at 45º angles), but then the notch on the cam is facing down in the 6 o'clock position.

[Bill/BentON Racing]

That;s right.When you found #1 to be not in position to adjust did you check #4? I'm sure it was in position to adjust.Check and see. Good Luck,Bill

[ekpent]

Correct,when setting valves for instance and plate is set at 1-4 T you have to physically check that the lifter arm is loose on that particular valve be it 1 or 4. #1 loose,set,turn plate one revo and #4 would be loose and ready for setting.