Electrics diagnosis please.

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hzbloke
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Joined: Tue Nov 15, 2011 2:24 am
Location: Bottom right corner of Oz

Re: Electrics diagnosis please.

Post by hzbloke »

Thanks for all the suggestions.

The battery seems to be charging fine. When it wouldn't (and still won't) start the battery was able to keep turning it over for many, many tries. The gen light works.

The ignition module certainly sounds like a possibility. What is it about plugs, leads and coil that make it fail? Thanks for the offer of a test one Steve, I'll do what testing I can before I ask for a lend of it.

When I crank the bike the tacho does move - the one test I have had time to do.

More news as it comes to hand.
1986 BMW R65
2008 Moto Guzzi Breva 750
2019 Kawasaki Z900rs
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mattcfish
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Joined: Mon Aug 02, 2010 11:18 pm

Re: Electrics diagnosis please.

Post by mattcfish »

hzbloke wrote:Thanks for all the suggestions.

The battery seems to be charging fine. When it wouldn't (and still won't) start the battery was able to keep turning it over for many, many tries. The gen light works.

.
Important details.
Could very well be an ignition trigger issue. I had a Boyer Branson leave me stranded in a tunnel at rush hour once.
I assume the timing is spot on...didn't come loose?
Bellingham, WA USA
1975 BMW R90/6
1975 BMW 2002
1971 VW Westfalia
1985 VW Vanagon
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Motu
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Joined: Wed Aug 04, 2010 5:05 am
Location: New Zealand

Re: Electrics diagnosis please.

Post by Motu »

hzbloke wrote: What is it about plugs, leads and coil that make it fail?
The old water analogy works - resistance and pressure. The coil has to work harder to jump a wider gap and to push through more resistance - the module doesn't know this, it thinks the plugs had the correct gap with sharp electrodes, and the leads are as per spec, and so is working harder to control the current draw.

Japanese cars put the ignition module in the distributor on the cyl head, the module is dumping heat into something at 95c. I spent years replacing them in Japanese cars. The Europeans are a bit smarter and put the module outside the dist, sometimes on an alloy heatsink - I've hardly ever seen a fried Euro ignition module. The airhead has it bolted to the frame under the tank, so there is some air flow. I'd like to see them on an alloy heat sink, and might do my own one day.... but they seem to be pretty reliable anyway.
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hzbloke
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Joined: Tue Nov 15, 2011 2:24 am
Location: Bottom right corner of Oz

Re: Electrics diagnosis please.

Post by hzbloke »

It's the coil. The primary winding had the right number of ohms, the secondary had none. I'm about to order a Dyna Coil from Motorrad Elektrik.

In doing some homework today I found that the coil that died came from a GPZ1000 Kawasaki so it may have been as old as my bike.

The other thing I found today was that pricing is akin to interpretative dance - you can make up anything you like. The local BMW dealer laughingly came up with $610. He actually did laugh at how ludicrous that is. Munich Motorcycles want $320, Motobins want $135 and the Dyna Coil (which seems to be well spoken of) is $95. It wasn't a difficult decision.

Thanks for all your help. I'll let you know if it works.
1986 BMW R65
2008 Moto Guzzi Breva 750
2019 Kawasaki Z900rs
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SteveD
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Re: Electrics diagnosis please.

Post by SteveD »

Always good to find the answer. Brown dyna?
Cheers, Steve
Victoria, S.E.Oz.


1982 R100RSR100RS supergallery. https://boxerboy81.smugmug.com/R100RS
2006 K1200R.
1994 R1100GS.
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