Re: Yamaha OX66 experts help I have a gremlin
and ill tell you again, the pulser coils on the OX66 DO NOT control ign timing unless an ign timing controlling sensor fails.
then the engine will lock base timing at 7 degrees BTDC and depending on the failure may lock it there for the entire throttle range.
means idle speed increases and top speed cannot be reached.
on an intermittant the winky blinky may be to slow to see it.
however my CD77 would.
lose a pulser input and you lose spark for that coils cylinder AND you lose injection for the affected cylinder.
if its a sensor failure, fuel is controled by the ECU based on other inputs.
usually fixed rich at low speed and lean above 4000.
its a very simple speed density type EFI system that uses a closed loop O2 sensor.
the pulser coil assy is mounted in a fixed position at guess what?
7 degrees before top dead center.
this allows the ECU,in the event of an ign timing control issue, to lock base timing at 7 BTDC idle speed increases and top speed may or may not be reached depending on the failed sensor.
the O2 sensor is NOT monitored by the ECU for failures but if its unplugged fuel is fixed rich at low speed and lean above 4000 DO NOT run above 4000 RPM.
however if the sensor is contaminated and telling the ECU the exhaust is rich it will react by leaning the fuel mix above 4000 RPM and burning pistons.
thats why at least yearly cleaning AND testing the o2 sensor output voltage is critical on OX66 engines.
and ill tell you again, the pulser coils on the OX66 DO NOT control ign timing unless an ign timing controlling sensor fails.
then the engine will lock base timing at 7 degrees BTDC and depending on the failure may lock it there for the entire throttle range.
means idle speed increases and top speed cannot be reached.
on an intermittant the winky blinky may be to slow to see it.
however my CD77 would.
lose a pulser input and you lose spark for that coils cylinder AND you lose injection for the affected cylinder.
if its a sensor failure, fuel is controled by the ECU based on other inputs.
usually fixed rich at low speed and lean above 4000.
its a very simple speed density type EFI system that uses a closed loop O2 sensor.
the pulser coil assy is mounted in a fixed position at guess what?
7 degrees before top dead center.
this allows the ECU,in the event of an ign timing control issue, to lock base timing at 7 BTDC idle speed increases and top speed may or may not be reached depending on the failed sensor.
the O2 sensor is NOT monitored by the ECU for failures but if its unplugged fuel is fixed rich at low speed and lean above 4000 DO NOT run above 4000 RPM.
however if the sensor is contaminated and telling the ECU the exhaust is rich it will react by leaning the fuel mix above 4000 RPM and burning pistons.
thats why at least yearly cleaning AND testing the o2 sensor output voltage is critical on OX66 engines.