Ignition Timing Check



I have a 2005 WR450 and reading through the manual I saw an topic on 'Ignition Timing Check'. See scanned image from the manual below.


I'm failing to paste an image here. Ok, I've managed to attach it.


My question is this: If this check fails, then is there anywhere to ajust ? I'm thinking of timing on the distributor on a car.

Or if it fails does it mean that the timing chain is incorrect on the cam sprockets ?


If cam timing is correct on TDC, then the ignition timing check should be ok.


If it is wrong, the manual reads: 'incorrect firing range - check rotor and pickup assembly'. There's nothing realy to check on the rotor (magneto) as this has a woodruff key and can only go on one way. As for the pickup assembly - what is it and where is it located ? The bits inside the rotor I guess ? How can one adjust this to get it within 'firing range'.


Just wanting to hear what others have to say about this topic.





Edited by alexszl

There's nothing to adjust on the ignition system.  The stator is under and inside the flywheel, part of it charges the ignition system.  Then theres a little coil on the outside of the flywheel that signals it when to fire.  Flywheels usually have a magnet or what looks like a strip of sheet metal welded to the outside that has to pass the signal coil to make it fire.  If the pickup coil is too far away from the flywheel maybe that could cause problems.   Or maybe the pickup coil resistance being too high or low.  The only reason for ignition timing problems I've seen on bikes with this type of system is a sheered flywheel key.  

If cam timing is off it won't affect ignition timing since the ignition is driven off the crank.  A wasted spark system.  There's an extra spark at the end of the exhaust stroke that does nothing.  

If you're having a problem with your bike running poorly it's most likely something else.  

Thanks for that flyandride.


I guessed something like that. Basically there's nothing to check to adjust - either it works or it doesn't.


I was just pondering with another thought. 4 stroke car engines have timing advance (the tiny vacuum hose - old school) - do modern dirt bikes have something like that (don't think so) or how does that work ?  computer CDI mapping ?


My bike is running sweet - just being Inquisitive to know more about 'Ignition Timing Check' and what is that all about.









Advance / retard curve is controlled by the CDI mapping

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