Checking ignition timing...

Joined
Feb 1, 2001
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#1
Hello,

On my 2000 Gas Gas XC 250 with EC ignition, there is no marks on the case to align with the mark on the stator for timing. It was sugessted use a degree wheel to check the timing, so I got a degree wheel. I am not sure how to use it though. I found TDC and marked the case & flywheel and set the degree wheel at 0 on the mark.

My question is from what point do I measure the degrees from TDC? Is it the distance from TDC to when the magnet on the flywheel just passes the pickup, or something else. The manual says 1mm BTDC, but how do I check this. I have never had to set or check timing without having a reference point on the case and stator to go by before, so this is new to me. Any help would be appreciated.

Thanks,
Domenic
 
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Feb 1, 2001
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#2
With the help of Steve at Motowest, and GlennP, I have found out that timing is checked when the magnet on the flywheel is centered under the pickup on the stator. I verified this with a timing light and by doing so found out that the mark on the stator and mark on the flywheel line up when the magnet is centered under the pickup, so that must be what those marks are for. Since there are no marks on the case, a dial indicated must be inserted into the sparkplug whole to measure the distance the piston is from TDC when a spark is triggered. This spec is 1mm.

Thanks,
Domenic
 

yarbonwick

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Mar 7, 2000
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#3
Good info, thanks.:)