DT65 rectifier smoked!

[lumpy_63]

The rectifier failed on my 1981 DT65 (smells very burned). Do I also have to replace the stator and CDI? If so, does anyone know where I can get a stator?!? Thanks.

 

[rodbolt]

Re: DT65 rectifier smoked!

testing as per service manual is the fist place, normal rectifier failures can be tracked back to bad battery connections or bad cables.
why would you check a CDI for a rectifier failure ?

 

[lumpy_63]

Re: DT65 rectifier smoked!

rodbolt, thanks for the reply. I will be doing some tests today. As for the CDI, I was told by a mechanic that I would probably have to replace it and the stator, too. I am not too electrically inclined so I appreciate any input you could give.

 

[deejaycee_2000]

Re: DT65 rectifier smoked!

The CDI hardly ever goes bad, they are expensive so the machancic might sell you your own one .... watch out for that ...

 

[rodbolt]

Re: DT65 rectifier smoked!

on that motor the CDI is completly seperate from the 12v system.
the stator is basically two coils, one is used to supply AC current to the CDI where its rectified and stored in a condenser until an ac signal from a pulser coil triggers an SCR to discharge the capacitor into the ignition coil primary windings.
the lighting coil provides AC current to the rectifier/regulator assy where it is rectified and sent to the battery as a modified DC or pulsed DC. some systems actually filter the DC pulses but I dont think the DT65 did.
both these coils sit under the flywheel. the lighting coil and charge coil derive the current from the magnets in the flywheel rim spinning past the stationary coils. hence the term stator.
CDI simply stands for Capacitor Discharge Ignition.
so what you need to do is look up the resistance specs for the stator and test the lighting coil for opens and shorst to ground. if it passes its ok. most rectifier failures are due to poor connections. it creates excessive heat in the components.
some of the 35-40 amp systems can generate enough heat to actually set the regulator on fire and melt the stator windings.
however the DT65 really does not produce enough amperage to fry the stator unless something really bad happens.
its very simple if you break each engine subsystem into its subsystems.
as a whole machine it looks complex, as subsystems its actually quite a simple machine.

 

[lumpy_63]

Re: DT65 rectifier smoked!

rodbolt and deejaycee 2000, thank you very, very much for sharing your knowledge of these motors and systems. You are a great help to a newby like me.