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  #1  
Old 06-02-2013, 02:46 PM
Flyguytki's Avatar
Flyguytki Flyguytki is offline
 
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Default P-mag timing question. urgent!

When timing p-mags does cylinder one have to be at TDC or can it be one of the other cylinders? The manual simply states rotate propeller to TDC.
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  #2  
Old 06-02-2013, 02:52 PM
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Omega232Devils Omega232Devils is offline
 
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Default any

Any cylinder will do!!!!

CORRECTION: You may time the PMag on either Cylinder #1 or #2 at TDC, compression or exhaust stroke does not matter. Verify TDC with mark on starter ring gear.
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Last edited by Omega232Devils : 06-03-2013 at 02:00 PM. Reason: Correction
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  #3  
Old 06-02-2013, 03:55 PM
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Flyguytki Flyguytki is offline
 
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Default

Thank ya much!
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  #4  
Old 06-02-2013, 08:42 PM
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frankh frankh is offline
 
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Default Mark on the flywheel

there is a mark for TDC on the flywheel as I remember.

I used the blow in the tube method but went away from that this last time.. just seemed an extra thing that might go wrong.. so I cleared the timing to its native timing, then set it up as close as I could.

Then I did the blow in the tube but it was only a fraction of a degree difference.

Frank
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  #5  
Old 06-02-2013, 09:17 PM
cguarino cguarino is offline
 
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Default Whoa!

Quote:
Originally Posted by Omega232Devils View Post
Any cylinder will do!!!!
I don't think that is correct. Number one can be on either the compression or exhaust stroke but it needs to be on one or the other. I don't think timing it with number three or four at TDC will work. It may work with number two at TDC but why do that. Just put Number one at TDC and blow in the tube. I may be wrong but if you could time it on any cylinder, then why would you have two coil banks? I'd either check deeper into this or just use number one to time your PMags. Good luck.
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  #6  
Old 06-02-2013, 09:27 PM
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Toobuilder Toobuilder is offline
 
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Default

#1 cylinder TDC - does not matter if on compression or exhaust stroke. The ring gear will be marked on the engine side to line up with the top split line of the case, or the propeller side will be marked to align with a pin inserted into the starter nose case.

There is no longer a "native" timing on the PMags... The "blow" method is the way to time them now. you can find what appears to be a "native" timing, but it is in fact a completely random artifact of the software.
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  #7  
Old 06-02-2013, 09:45 PM
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Don Patterson Don Patterson is offline
 
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Default P-Mag timing

#1 cylinder TDC - does not matter if on compression or exhaust stroke
Is correct.
Make sure you are spinning the prop in the direction of rotation before stoping at the TDC position. Don't spin the prop beyond TDC and back it up. That would put back lash in the timing gears which would give you an error in timing.
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  #8  
Old 06-03-2013, 06:51 AM
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Omega232Devils Omega232Devils is offline
 
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Post From the manual

Quote:
Originally Posted by cguarino View Post
I don't think that is correct. Number one can be on either the compression or exhaust stroke but it needs to be on one or the other. I don't think timing it with number three or four at TDC will work. It may work with number two at TDC but why do that. Just put Number one at TDC and blow in the tube. I may be wrong but if you could time it on any cylinder, then why would you have two coil banks? I'd either check deeper into this or just use number one to time your PMags. Good luck.
From the 114-Series Installation manual:
"-Rotate your prop to the engine TDC (or TC) timing mark (see exception
Note 4) . By approaching this mark with the prop moving in the direction of
normal engine rotation you can minimize play in the gears.

Note 2: It does not matter whether the engine is on the compression or
exhaust stroke for a particular cylinder. "
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  #9  
Old 06-03-2013, 08:37 AM
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Flyguytki Flyguytki is offline
 
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It seems everyone is correct, as long as it is at TDC for any one of the cylinders you are good to go, We retimed the mags during troubleshooting this weekend after I had my first flight adventure on saturday and this was the main questions that came up, does it matter which. The answer is No it does not matter.
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  #10  
Old 06-03-2013, 10:11 AM
cguarino cguarino is offline
 
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Default It does matter!

Quote:
Originally Posted by Flyguytki View Post
It seems everyone is correct, as long as it is at TDC for any one of the cylinders you are good to go, We retimed the mags during troubleshooting this weekend after I had my first flight adventure on saturday and this was the main questions that came up, does it matter which. The answer is No it does not matter.
I just called my friend, Brad, over at EMag. We had a long discussion and the answer is it does matter. You could time it with either 1 or 2 at TDC which is going to be the same. However, you can not time it with 3 and 4 at TDC. Time it with the TDC mark. Compression or exhaust doesn't matter but DON'T time it with 3 and 4 at TDC. I hope this helps.
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