Tech Tip: Dyna 300 Rev Limiter

[XJ900...@aol.com]

                I recently upgraded my ignition to include a DynaTek -- Dyna-300 Rev Limiter ... chiefly because the 300 has an "Ignition kill" function that can be used as an Anti-theft feature.

                When a hidden switch is closed ... to provide 12 Volts to the Kill feature ... the engine will NOT start.  Most thieves won't troubleshoot ignition's ... so, the "Kill" feature is a nice option.

            The same wire can be used with an Intermittent On Switch -- so, that you can kill the engine, momentarily -- for clutch less shifting up through the gears in a Drag Racing configuration.

 

                Those, installing a rev limiter, to protect the engine -- by setting an upper limit below the Red Line will need the following information if using a device from DynaTek.

 

                The DRL-300 requires a feedback signal from the coils that is GREATER than found on Yamaha's manufactured in the early eighties.  Stock coils and igniter will not supply enough energy to activate the rev-limiting function.

                DynaTek supplies owner's of -- Yamaha Inline Four's -- with a small add-on kit containing small transistors to boost the signal needed to activate the rev limiting function.

                When the kit is soldered ... inserting it between the Limiter Box and the coil's Ground wires, enough energy reaches the Limiting Box to activate rev limiting.

 

                Also of interest -- is the "Set-up" required to make the limiter "See" that your ignition is -- Two coils firing four cylinders.

                The Default setting on the limiter reads the ignition pulses from the pick-up coils incorrectly.  Therefore ... setting the dip switches to read 4 impulses from the pick-up's -- every two revolutions of the crank shaft -- needs to be over-rided.

 

                The default setting of recognizing 4 pulses per 2 crankshaft revolutions -- actually activates the limiting function by fifty-percent -- such that -- setting the pot to 9 K will have the limiter "Kick-in" at 4.5 K.

 

                This problem is easily rectified by setting the dip switches to a lower setting and tweaking the pot to "Find" the high limit after the dip switches give you a new set of parameters -- which are higher than what the values are found marked on the unit.

 

 

                RickCoMatic