Re: Timing, 93 Yamaha 250
base timing is physically set at 7* BTDC by the physical loction of the pulser coil assy.
main timing modifiers are the TPS and the CPS with additional inputs from the temp sensor and the knock sensor.
if everything isd set up according to the Yamha mnual idle timing will be about 6* ATDC and wot about 18* BTDC.
figues are not set in stone and can be modified by the ECU based on the various sensor inputs.
thats how if the ECU "sees" a sensor failure idle speed increases due to the 7* BTDC timing and top speed normlly cannot be reached still due to the base 7* BTDC timing.
its also how most times we can trouble shoot a motor based on what its doing.
dont belive it,unplug the knock sensor and see what RPM does.
just dont have the motor in gear hanging off the transom when you do it.
bystanders tend to laugh
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