Motoplat testing

[Auto5guy]

When testing a 2 wire internal rotor Motoplat stator are the Ohm values supposed to be the same as an external stator with red connectors?

Matthew

WARNING: The Surgeon General has determined that castor smoke can be hazardous to your health.  It is highly addictive and causes delusions of grandeur.

[TGTech]

Matthew,

   First off, be aware that Motoplat never sanctioned resistance testing of any of their CDI type stators and coils. Husqvarna and Sachs did publish figures in their literature with figures, but they were "on their own" as far as the accuracy goes. Motoplat only gave their blessing to actual dynamic testing.

   As far as using the same readings, I can't believe that they would be the same figures, because the RPM test figures in dynamic testing, are dramatically different between the two types of ignitions. The internal rotor systems, late model versions, were supposed to be producing an 8mm   spark by 480 RPM, while the external flywheel models, were not producing an 8mm spark until 800 RPM. The capacitor charge coils in the internal rotor type systems were much larger than those in the external flywheel versions.

Dane

[Auto5guy]

Dane

So are we just fooling ourselves when we test with a multimeter and the specs posted in the yahoo site?  I'm to cheap to send all my components in to be tested and to lazy to pull a flywheel over and over to test them at home.

I have some components that read infinity when they should give a readable value.  Those are clearly burned open inside.  The 2 internal rotor stators I have both read 7 Ohms wire to wire.  Less than half what the external one would read.  Based on what you just said that could be meaningless.

I guess I won't know until I try them.

Matthew

WARNING: The Surgeon General has determined that castor smoke can be hazardous to your health.  It is highly addictive and causes delusions of grandeur.

[TGTech]

Matthew:

   To be very honest, I've never even looked for or read any resistance testing specs, because of the information from Motoplat's engineers. Since they were the electronics experts regarding their systems, why should I question their knowledge? And besides, I've got the dynamic test bench here to do the actual function test on anyway.

   One other thing that I've learned over the years of testing the PVL systems, some parts of which can be resistance tested, is that there is a caveat regarding resistance testing. If you test a part and it shows that it's bad, it normally is. But if you test it and it falls into the range of acceptability, then you're still only partially sure that it will work OK. There is still a chance that actual factors that the engine adds, can make the part not function.

   The bottom line, is that running the ignition on the test bench, is the most accurate testing procedure because you can actually load the system.

Dane

[Rain Man]

Dane,  I have an internal rotor ignition on my  MC250.   So does  the 450 rpm and 8mm spark contribute to the bike starting 1st kick, even when cold ??
  This is the best starting 250 I've ever owned.
  Even the MZB equipped 6 day needs 2 kicks, minimally.

Also can you still purchase the Internal rotor ignition ??

Raymond
 Down East Pentons

[TGTech]

Raymond,

The spark threshold of the internals does contribute to the easy starting. The 250 engines kick started at about 625 RPM's, so the low spark threshold of the internals are far enough below the normal kickstarting speed, that they'll light the engines pretty easily.

Dane

[sparks]

Mathew,

I know this might be a bit late but I thought I would put it, there are two types of internal rotor system you say yours measures 7 Ohms this is a straight line ignition with no maping the other measures 4.5 Ohms this has about 10 degrees of advance, this system was generally usde on 250cc engines.



Regards

Steve.
UK Motoplat.

[Rain Man]

One thing I've been doing with some of these "rebuildable Pentons" I've been picking up is to hook a Radio shack (wicked cheap) Analog meter to the motosplats output and  kicking the motor over.  You should see that meter move up to almost 6v.
 The digital meters don't seem to give an "honest measurement"
 while kicking the motor over.
 Don't forget to leave the spark plug hooked up either

Raymond
 Down East Pentons