Author Topic: Anatomy of a CX500 Cdi unit  (Read 1375 times)

Offline mike the bike

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Re: Anatomy of a CX500 Cdi unit
« Reply #30 on: November 12, 2017, 09:38:19 PM »
The potting, as previously discussed,  wasn't always 100% which affects the solder joints due to atmospheric exposure and, over time, capacitors go leaky so it was always going be pot luck if a CDI lasts 50k or 500k.  Upgrading with modern capacitors,  metal film resistors etc, and re potting the pcb properly will make the CDI outlast the bike.
German reliability is a myth spread by the Hitler Youth

Offline Oddjob

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Re: Anatomy of a CX500 Cdi unit
« Reply #31 on: November 12, 2017, 11:46:50 PM »
Couldn't have said that better myself Mike, perfect reply.
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Offline AshimotoK0

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Re: Anatomy of a CX500 Cdi unit
« Reply #32 on: November 13, 2017, 12:38:37 AM »
 ;D ;D ;D ;D ;D

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“Alright friends, you have seen the heavy groups, now you will see morning maniac music. Believe me, yeah. It’s a new dawn.” Grace Slick, Woodstock '69 .. In the year of the Sandcast.

Offline Woodside

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Re: Anatomy of a CX500 Cdi unit
« Reply #33 on: November 13, 2017, 07:23:14 AM »
as to the potting what will you use to reseal the cdi

Offline AshimotoK0

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Re: Anatomy of a CX500 Cdi unit
« Reply #34 on: November 13, 2017, 01:42:32 PM »
as to the potting what will you use to reseal the cdi

Not sure Jason..possibly silicone dielectric gel. I still need to come up with a test rig setup and enclosure. Engine looking really good though so definitely worth all of the effort.
“Alright friends, you have seen the heavy groups, now you will see morning maniac music. Believe me, yeah. It’s a new dawn.” Grace Slick, Woodstock '69 .. In the year of the Sandcast.

Offline Woodside

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Re: Anatomy of a CX500 Cdi unit
« Reply #35 on: November 13, 2017, 01:55:07 PM »
sound good is it this stuff

http://www.google.co.uk/shopping/product/5009981323735501408?lsf=seller:87981,store:8414587908041704960&prds=oid:5468991119695532258&q=magic+gel&hl=en&ei=kaMJWo_yC-KNgAaW6qCoBw&lsft=gclid:EAIaIQobChMI4NvdoNm71wIVypTtCh2uxQDjEAQYASABEgLCn_D_BwE


anyway we use this and can submerge 230v joints pretty much underwater ...
i took apart an underground joint filled with this after 3 years to add some more circuits and it was as good as new...and it was pretty much in a bog

Offline AshimotoK0

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Re: Anatomy of a CX500 Cdi unit
« Reply #36 on: November 13, 2017, 04:22:27 PM »
sound good is it this stuff

http://www.google.co.uk/shopping/product/5009981323735501408?lsf=seller:87981,store:8414587908041704960&prds=oid:5468991119695532258&q=magic+gel&hl=en&ei=kaMJWo_yC-KNgAaW6qCoBw&lsft=gclid:EAIaIQobChMI4NvdoNm71wIVypTtCh2uxQDjEAQYASABEgLCn_D_BwE


anyway we use this and can submerge 230v joints pretty much underwater ...
i took apart an underground joint filled with this after 3 years to add some more circuits and it was as good as new...and it was pretty much in a bog

Yes similar but the stuff I have used in the past was made by  Dow Corning.
“Alright friends, you have seen the heavy groups, now you will see morning maniac music. Believe me, yeah. It’s a new dawn.” Grace Slick, Woodstock '69 .. In the year of the Sandcast.

Offline Woodside

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Re: Anatomy of a CX500 Cdi unit
« Reply #37 on: December 06, 2017, 01:32:06 PM »
ash im using some
wiska mpgel plus...today
google it if its any good ill try and save some for you

Offline Woodside

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Re: Anatomy of a CX500 Cdi unit
« Reply #38 on: December 06, 2017, 01:32:55 PM »
code on box is
mp01100w

Offline AshimotoK0

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Re: Anatomy of a CX500 Cdi unit
« Reply #39 on: December 06, 2017, 01:42:08 PM »
code on box is
mp01100w

Wow ..cheers Jason
“Alright friends, you have seen the heavy groups, now you will see morning maniac music. Believe me, yeah. It’s a new dawn.” Grace Slick, Woodstock '69 .. In the year of the Sandcast.

Offline AshimotoK0

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Re: Anatomy of a CX500 Cdi unit
« Reply #40 on: July 28, 2018, 04:40:14 PM »
Well the bike is for sale on eBay as a non-runner. One bike project too many and not really my 'bag'. https://www.ebay.co.uk/itm/142870424113?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649


However, I recently fully rebuilt the CDI and rehoused it as shown in the pics on the bike.

Problem is I can't really test it without trying on a bike or building a simulator  for the pulser pickups etc but I am pretty sure it will work OK. In the picture is the silicone dielectric gel that Jason (Woodside) kindly donated. The intention was to re-encapsulate the PC once it was found to be running OK.

I have put an appeal into 'Desperately Seeking' for another duff CDI, so that I can carry on the good work. My next step was to come up with a simulator. OK I won't have the bike anymore but I hate  to have 'unfinished business'.  RGP750 .... I blame you for all of this  ;D ;D

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« Last Edit: July 28, 2018, 04:42:15 PM by AshimotoK0 »
“Alright friends, you have seen the heavy groups, now you will see morning maniac music. Believe me, yeah. It’s a new dawn.” Grace Slick, Woodstock '69 .. In the year of the Sandcast.

Offline rozabikes

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Re: Anatomy of a CX500 Cdi unit
« Reply #41 on: July 28, 2018, 08:04:32 PM »
Looks a great buy for someone Ash. Super find!
One day I'll have the time to restore it, not just talk and dream....

Online Laverda120

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Re: Anatomy of a CX500 Cdi unit
« Reply #42 on: July 29, 2018, 11:02:34 AM »
Great looking bike Ash. I've sent the details off to a mate who's looking for an older Honda to ride and clean :)

Offline AshimotoK0

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Re: Anatomy of a CX500 Cdi unit
« Reply #43 on: August 07, 2018, 10:14:11 AM »
Well I will be CX less next Monday and the bloke buying it is sending it to a restorer in Anglesey and keeping it standard. Happy it's going to a good home ... he had one 35 years back and wants to get back on a CX.

I am still looking for another duff CDi though if anyone has one. to continue my 'experiments'

I did come up with a crude 'ish test method which tests out the main part of the CDI but not the auto advance function.

I fed the HT AC input from a modified cheapo 12-> 240 volt inverter I got off eBay. I basically bypassed the DC and 50Hz frequency synthesis bit of the inverter and wired  straight out of the HT transformer into the CDI. How they can make these little inverters in China and sell for less than £10 beats me.

https://www.ebay.co.uk/itm/150W-Car-Power-Inverter-Adapter-12V-DC-into-11V-220VAC-with-USB-Charger-Port-GY/253755535569?_trkparms=aid%3D555017%26algo%3DPL.CASSINI%26ao%3D1%26asc%3D53379%26meid%3D260deeeafa78406e87de83fe8017ab96%26pid%3D100705%26rk%3D1%26rkt%3D1%26%26itm%3D253755535569&_trksid=p2045573.c100705.m4780

So, for anyone familiar with the CX CDI ( or who is interested ;)) , the high voltage from the inverter feeds into  the White and Blue leads on the CDI. ( this AC voltage is normally provided on the bike by an extra coil on the alternator). This AC high voltage is rectified by diodes inside the CDI and charges the main discharge capacitors via the ignition coil primaries. After connecting the coils to the CDI and powering the CDI from the inverter, I fed one phase coil of a stepper motor ( scrap from an old laser printer) between the green wire on the CDI and the Orange (left coil) and Light Blue (right coil). You then spin the stepper motor shaft slowly by hand and you should get a healthy spark across the plug attached to the secondary of the ignition coil. The stepper coil works in reverse to normal, generating pulses from its coils when spinning inside the magnets. These pulses trigger the thyristors in the CDI, via a network of resistors and capacitors. Obviously, these pulses would normally come from the pulser coils rotated by the engine when fitted to a bike.
« Last Edit: August 07, 2018, 11:29:58 AM by AshimotoK0 »
“Alright friends, you have seen the heavy groups, now you will see morning maniac music. Believe me, yeah. It’s a new dawn.” Grace Slick, Woodstock '69 .. In the year of the Sandcast.

Offline Seabeowner

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Re: Anatomy of a CX500 Cdi unit
« Reply #44 on: August 07, 2018, 01:14:22 PM »
Well I will be CX less next Monday and the bloke buying it is sending it to a restorer in Anglesey and keeping it standard. Happy it's going to a good home ... he had one 35 years back and wants to get back on a CX.
Wow that must be a wrench letting that go Ash. There must be a couple of bidders kicking themselves. A unique opportunity.
But I hated them at the time, so I must stick to form. Glad it's gone to a good home.
Phil
1971  CB500K0
1973  CB500K1
1975  CB550F1
1978  CB550K