[Electrical] CDI Ignition Timing

[rananthan3]

I have a Huasheng 142F 49cc engine with CDI. The question I have is what kind of CDI is it. Does it advance the spark timing with engine rpm i.e have a curve? What is the procedure for adjusting the timing?

I have read online that the easiest way to tune the ignition timing is by making marks on the flywheel to indicate TDC and an appropriate mark on something stationary. Then use a timing light to determine whether you have the appropriate number of degrees before top dead center (BTDC).

The only solution I have come across is using an offset key for fine tuning. It seems like the position of the flywheel is fixed based on where the keyway is relative to TDC. The article below has a good explanation. On our forum there is a good solution too. If the key is too thin, obviously that will be disastrous.

http://www.foxvalleykart.com/timing2.html

http://www.motoredbikes.com/showthread.php?32572-66cc-timing-help-tips

Here is an excellent explanation of CDIs on this forum:

http://www.motoredbikes.com/showthr...ion-systems-trouble-shooting-how-do-they-work

Here is the CDI for the Huasheng engine:

http://www.bicycle-engines.com/Ignition-CDI-Coil-for-142FG-and-142F-1G-Engines.html

 

[rananthan3]

The article below explains how the stepped shape of the trigger coil core determines the advance.

http://archive.siliconchip.com.au/cms/A_110499/article.html

 

[rananthan3]

http://www.motoredbikes.com/showthread.php?39926-Timing-Advance