Clinician
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Post by pretendentas22 on Sept 5, 2012 1:07:09 GMT -6
I would say it is cold misfire/backfire.
I will sound a bit stupid now but I am just trying to understand misfire/backfire and their link to cam sprocket. I always thought misfire/backfire is caused by spark which comes out before piston reaches TDC or after it passed TDC. And for it is responsible CDI, trigger pick up coil and flywheel. Where cam sprocket only operates valves opening time and makes sure they are closed or opened at certain time.
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Post by pretendentas22 on Sept 4, 2012 13:52:12 GMT -6
Hi again,
At the end I assembled the engine and still have problem. In the mornings it started ok but i constantly was hearing noise. It sounded like a light blow. These blows come repeatedly in couple seconds intervals. When it blows rpm gauge is jumping as well. Plus when the engine still is cold after couple blows it just stops, unless I keep it on high rev. Does anyone had similar problem? it is a bit difficult to explain but I hope you will get me.
I am thinking may be because alignment isn't proper the valves and timing just doesn't operate properly.
Valve clearance is done.
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Post by pretendentas22 on Aug 3, 2012 2:37:10 GMT -6
I like the idea with screws  very good. Thank you all for the help  all I need now is to get last part from China and see how it starts. |
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Post by pretendentas22 on Aug 2, 2012 5:33:16 GMT -6
Thanks for the advice I will definitely check it. Other thing which concerns me is non-adjustable ignition time. The current gap between ‘F mark’ and actual TDC is longer than factory’s is set and I think it will cause an advanced fire. Is there any way around it? |
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Post by pretendentas22 on Aug 2, 2012 0:44:08 GMT -6
Yes the head is tighten down. Is it save to run like this or it will cause me problems?
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Post by pretendentas22 on Aug 1, 2012 23:25:34 GMT -6
Yes, the tensioner is off and chain on the gear.
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Post by pretendentas22 on Aug 1, 2012 14:26:45 GMT -6
This is the picture where is my TDC.  At TDC this how I am able to set cam  if I align the cam - the mark is moved to this position  It is first time I am involved into timing and don't want to smash the valves. Is it safe enough to leave it as it is? |
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Post by pretendentas22 on Aug 1, 2012 3:48:19 GMT -6
I found TDC by physically checking piston’s move and problem is if my cam sprocket is aligned correctly and piston at TDC I can’t put on the chain without turning cam sprocket to the left or right. My question would be is it better to have cam sprocket aligned before piston reach TDC or after?
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Post by pretendentas22 on Jul 31, 2012 23:42:38 GMT -6
Hello All, I have small problem I had to replace crankshaft on my GY6 125cc and now can't set up timing. When piston is at TDC the chain doesn't allow to align cam sprocket, I mean cam sprocket marks are or half tooth too early or half tooth behind. Any Ideas how to match TDC with camshaft? |
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very good. 
all I need now is to get last part from China and see how it starts.