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blanc

01 Beta Rev3 250 Electrical Problems

19 posts in this topic

Hi All,

I bought an 01 rev3 250, I bought it as a non runner. (Didnt spark)

I bought a new ht coil, lead and spark plug cap that didnt fix the problem. I realise that these bikes have cdi and stator problems can a newer model be fitted to cure the electrical problems? Also how do I test both the cdi and stator to ID the problem?

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When it happened to mine, Lampkins sent me a CDI and a stator, charging me for both. He told me to try them one at a time, the CDI first, and return the part which I didn't need which he then refunded me for. You'll need a flywheel puller as well.

In 2004 it was about

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Hi Blanc,

I've just bought an 01 Rev3 and so am keeping my eyes on the various electrical threads ready for (what me be) the inevitable! I have a few comments:

Mine didn't start on Sunday. This was the first time I've tried apart from when I collected it. It had intermittent spark. It turned out to be the nut securing the coil earth to the coil had come off. Relief or what! It does bring into focus a point I made on another thread; electics need security. Before you do anything else, disconnect, clean and reconnect everything. Corrosion ALWAYS affects the earth route (it's known as 'black wire syndrome', or dendritic corrosion); once you lose an earth on the generating circuit, the regulator doesn't,er, regulate and the generator is under free load. It's all over then!

Secondly, a stator plate is not a Saturn V control panel! I defer to those with more Rev3 experience, but I'm guessing there's going to be 2 or 3 coils of wire and a crank position sensor? It should be an easy job to test this. There will be a nominal resistance across each coil and between each coil end and ground (should be open circuit). The Crank position sensor may require a slightly more involved test, but any auto electrician should be able to put a scope on it and rotate the crank to find a pulse.

What we need on here is a nice definitive resistive test for the coils that anyone with a

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Thanks all, Graham nice informative post.

A quick question, the ht coil. Is it secured to the frame or is it secured via the plastic shield by a bolt? Surley a bolt will not ground as good as the frame?

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Blanc, This was my problem!

It's attached to the black plastic shield (presumably to preven vibration damage). The top mounting bolt incorporates an earth lead on nice flimsy 16 or 20/0.2 wire. There was no star washer to bite into the earth tag. If I were you I'd take the radiator out and get into this area and check all the wiring.

Regarding dentritic corrosion (actually less of a problem on a trials bike because it has no battery so this form of galvanic corrosion only occurs when the bike is running); you can identify this by a dull appearance to the strands of wire in the crimps. If it looks like this, replace the whole thing! I'm tempted to replace all the earths with plastic coated wire braid. It has significantly larger surface area and is much more robust. It can only help...

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Thanks again.

Im quite tempted to make up a complete new wiring loom. It looks so simple, thats the first time I can say that on a bike.

In relation to the cd/stator...DOES ANYONE KNOW HOW TO TEST THESE??????????

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Yep. You will have to work out exactly which wires do what as the wiring diagram in the owners manual is not too specific, but we have a lighting coil, a source coil (for the ignition) and a crank trigger for ignition (2 of them on my Techno). The ignition source coil will look "individual" i.e. there will only be one coil that looks like it. The lighting coils are just that - many, going virtually all around the stator and all connected together ( 5 on my Techno) . The trigger (or 2) are encased in black plastic, are smaller and often have little metal posts sticking out of them. The source coil should measure roughly between 20 to 200 ohms. Any less (0 - 2 ohms ish) and they are shorted, any more (100 000 ohms +) and they are open circuit somewhere. They should not have a circuit to ground. Someone may have the actual specs for our Betas. This is a good ballpark figure though. The actual output measured with an AC voltmeter should be a minimum of about 60 volts kicking it over.

The crank trigger resistance should measure around 300 ohms. Same as above for the rest - 0 ohms and 500+ is no good) You should see AC output around 0.7 volts at kickover. Again ballpark figures but if there is a problem it will be quite different from these.

Yellow and Brown appear to be for Lighting purposes on the early Rev 3, Red and Black are Source Coil? and the Trigger... I cant see it on the diagram.

Post your results and this will help others in the future by perhaps building a reference for the various models and specifications for testing.

HTH,

Cheers,

Stork

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Well done Stork, sounds reasonable to me.

When I rewound my GS550 alternator, I went to a transformer winder and they measured the wire for me and sold me enough for 3 rewinds for a quid. I then counted the turns off the former and wound the right number on by hand. Once happy, I took it back to the winders and they dipped it in hameg laquer and baked it on for me. I'd be confident of doing the same to any stator coil. Certainly, if it's Donald Ducked I'd have nothing to lose!

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I have wound the odd source coil before. The more you can get on them the merrier. Triggers are a different kettle of fish. I suspect they are reliable as it seems that most Beta stators are fixable so the source coil is the next item on the list. Use the same gauge and get as much on as you can. It wont hurt anything.

Good luck!

Cheers,

Stork.

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Readings from the coil and pickup look good, is there anyway of checking the CDI using a multimeter?

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Also the lighting is not plugged in but the rectifier is still bolted to the frame, would this effect the spark?

Edited by blanc

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Theres no real way of testing CDI's apart from substitution with a known good one. Its unlikely to be the culprit although we are talking Italian electrics here (no offence intended). I dont think the rectifier would affect the ignition system, although it will definately affect the cooling fan. It must be fitted for that to work. Further checks to the actual ignition coil are in order, test the primary side (the single wire from the CDI and ground) it should be around 3 ohms. The secondary side (stick one probe into the plug cap and the other to the primary wire) should be something like 10 000 ohms - 16 000 (10 - 16 K) and without the plug cap about 6000 ohms - 10 000 ohms IIRC. Obviously major differences are an issue here. It is not unknown for the plug cap to fail. I have seen CDI's fail because a resistor type plug was specified but not used, pretty rare however. Double check all the electrical connections everywhere as described above.

See how this goes,

Cheers,

Stork.

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Thanks again. Will test over weekend and revert back with results. Dam spanish electrics

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I have 7 wires running in behind the flywheel.

Got the following readings all between the wire and the frame.

Yellow -which runs to the ht coil - short

Red - runs in to CDI - open circuit

Black/white - runs in to CDI - 200 ohm

White - runs in to CDI - 200 ohm

Brown - runs in to CDI - short

Black - Open circuit

Getting about 40- 50 volts AC out of the ht coil?

Edited by blanc

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