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Old 04-24-2021, 05:42 PM   #1
Jobo101   Jobo101 is offline
 
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TDC for valve adjustments?

Instead of finding TDC, why couldn’t you turn the engine until one valve opened
And adjust the other?


 
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Old 04-24-2021, 06:37 PM   #2
Bill Hilly   Bill Hilly is offline
 
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I have never did the TDC method on mine. I just pull the spark plug, so I can easily, turn the motor ,slow enough to control were I stop. I make sure the compressed spring is far enough into it's travel that I won't have to deal with the potential of any overlap.I adjust them, then I the spin the motor around, and check them again. It's no faster of a method. It's just how I choose to do it.


 
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Old 04-24-2021, 07:50 PM   #3
Megadan   Megadan is offline
 
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Quote:
Originally Posted by Jobo101 View Post
Instead of finding TDC, why couldn’t you turn the engine until one valve opened
And adjust the other?
Because the CG engine uses a single cam lobe, and the window where the exhaust valve is open and the intake doesn't have any ramp pushing on it is very small.

In theory you could do it the way you describe, but considering the difference in steps between your method and simply putting it on TDC involves removing one small cap on the top of the stator cover?
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Old 04-24-2021, 11:30 PM   #4
Jobo101   Jobo101 is offline
 
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Quote:
Originally Posted by Megadan View Post
Because the CG engine uses a single cam lobe, and the window where the exhaust valve is open and the intake doesn't have any ramp pushing on it is very small.

In theory you could do it the way you describe, but considering the difference in steps between your method and simply putting it on TDC involves removing one small cap on the top of the stator cover?
It seems that if one valve is open the other would not have any pressure. But I agree that that the effort is about the same.


 
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Old 04-25-2021, 02:15 AM   #5
Megadan   Megadan is offline
 
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Quote:
Originally Posted by Jobo101 View Post
It seems that if one valve is open the other would not have any pressure.
True, except for the concept of valve overlap that happens between the exhaust valve closing and intake opening. That means that you would have to catch the exhaust valve during it's initial opening,

For me it's just a matter of doing things the right way to eliminate any potential mistakes. Setting a single cylinder engine at TDC is probably one of the easiest things in the world to do, and the valve job on a Hawk can be done in just a few minutes whilst holding a beer in one hand.
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Old 04-25-2021, 03:41 AM   #6
Big Bird   Big Bird is offline
 
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I will admit I have done some lazy valve adjustments before but that was multiple cylinder engines. You are trying to save like 10 seconds lol.
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Old 04-25-2021, 09:00 AM   #7
idle_purr   idle_purr is offline
 
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Being a novice myself, I personally thought that setting it to TDC was the most straight forward and easy to understand method for adjusting the valves. It was as simple as finding the T on the flywheel while the engine was compressed, you could feel it in the ratchet.

So unless you really understand what you're doing, I would suggest finding TDC just to eliminate the room for error.

Also, I understand you are not comparing which method is better. Just chiming in cause I recently adjusted my valves twice, once to .05mm but then decided to readjust them to .07mm until the engine is fully broke in. Either way the valves on the cg 250 come tight as fu%k and definitely require the attention. I feel like every time my engine revolves it whispers thank you.
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Last edited by idle_purr; 04-25-2021 at 10:58 AM.
 
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Old 04-25-2021, 05:17 PM   #8
Jobo101   Jobo101 is offline
 
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Thanks for the education folks! I didn’t realize that there was overlap.


 
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