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Barnett Trials

TR34 Electrics

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Can anyone help ?

No spark from a TR34 I've just bought. Looking at the electrics:-

Blue and brown wires come from the bottom terminal of the coil. Blue goes into the harness, brown is split into two, but unconnected (has there been a kill swithch ??)

Black wire comes off the top terminal on the coil - goes into harness

Green wire comes out of harness, goes nowhere. Yellow wire comes out of harness and loops back in.

Fitted a new spark Plug cap (the original looked well used).

Before I start on anything expensive - any ideas ?

 

cheers

John

 

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Check the ignition first you might have a faulty Motoplat ignition, the fault can be either in the coil (fiited with incast electronics) or the stator also fitted with internal electronics in both are diodes build in which fail very easy.

I hope you know how to measure if thes items are sound or not with a multimeter, if not, you have to use a multimeter with diode test, you can check the flow voltage of the diodes in both directions as a quick diagnosis.

The attenuated current direction is the voltage drop with a milliamperesed sample current for example 527 MV and when the two cables (red and black) are exchanged, the flow voltage of the other diode (without 30 ohm resistor) is measured, the voltage drop (or the flow voltage of the diode) should then be about 500 millivolts! However, the specified flow voltages are only indicative, because they are also highly temperature dependent. However, if one of the two flow directions does not yield a reasonable reading or infinitely high flow voltage, the fault is clearly localized.

 

I know heavy stuff and even more worse to translate in proper english … anyway I had the same problem and with a replacement of the diodes the bike run again.

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6 hours ago, Barnett Trials said:

Can anyone help ?

No spark from a TR34 I've just bought. Looking at the electrics:-

Blue and brown wires come from the bottom terminal of the coil. Blue goes into the harness, brown is split into two, but unconnected (has there been a kill swithch ??)

Black wire comes off the top terminal on the coil - goes into harness

Green wire comes out of harness, goes nowhere. Yellow wire comes out of harness and loops back in.

Fitted a new spark Plug cap (the original looked well used).

Before I start on anything expensive - any ideas ?

 

cheers

John

 

I know your bike's been around for many years now and I'm sure it would've reared it's ugly head a long time ago but I had one from new and the flywheel cover wouldn't fit flush with the casing because the brass inserts weren't set in properly. It was a pig due to water getting in.

It gave me the runaround until I sussed it out !

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 Have you pulled the flywheel yet? The early Beta's would shear the flywheel key on a regular basis.

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