Condensor 'bodge'

[A100man]

All

Suspect at least one faulty condensor on the GT 250 - difficult to start (arcing at one set of points..)

Want to try out my theory NOW (Eaaster w/e and all that). I can prob get a old school Beetle condensor to bodge fit locally rather than wait a week - thoughts?
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Now: A100, GT250A, XJ598, FZ750

Then: Fizz, RS200, KL250, XJ550, Laverda Alpina, XJ600, FZS600

[Robby]

Give it a go.

[steve the grease]

I believe there's a range of capacitances used , probably depending on the magnetic flux the coil develops - which is a function of turns and current flow. Yeah it will work , but maybe not 100 %.

" Almost all automotive coils use a 0.25-0.29 microfarad capacitor."

found online.
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All the above is my personal opinion, you can see my lips move, but I'm talking out of my arse.
I've been riding, and fixing , bikes for 50 years, in that time the more I learn, the less I am absolutely sure of.....

[stinkwheel]

Swap the condensers round and see if the arcing changes to the other set.

The old test used to be to set the points to closed with the ignition off. Turn it on then seperate the points with something non-conductive. If a spark arcs across, the condenser is probably toast. Of course, this doesn't work if it's a self-exciting ignition.

Make sure the voltages match if you are using componants off different motors (not sure if the GT is 6V).
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Easy-X]

[stinkwheel]

[Easy-X]

It's all a bit hazy but from what I recall of capacitors in general (bearing in mind I did GCSE Electronics >30 years ago) one would use a capacitor rated to the voltage expected or higher. E.g. making a regulated 12V power supply? Use at least 15V capacitors.
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Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[A100man]

[jeffyjeff]

[WD Forte]

As long as the condenser/capacitor is rated at or above running voltage you're good to go, It wont affect current
The important thing other than rated voltage is operating temperature but any automotive type (as opposed to a PCB type) will probably be up to the job.
As to any differences in capacitance, you'd need a scope to see how it operates but even with a scope what are going to compare it to?
as long as its near or near enough I wouldn't worry.
Most auto caps are low capacity, high temp.

Other than the above volts and temp, physical dimensions and getting it to fit would probably be my main concern
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bikers smell of wee

[A100man]

Hmm,Beetle condensor didn't seem to work too well.. points on that pot still arcing. Went for a ride anyway, at the end of about 15 miles misfire, nursed it home.

Maybe points/condensor or non charging battery. More investigation needed, as usual..
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Now: A100, GT250A, XJ598, FZ750

Then: Fizz, RS200, KL250, XJ550, Laverda Alpina, XJ600, FZS600

[pepperami]

[WD Forte]

As well as closely examining the condition of the faces of the points
I'd be checking ground continuity from the points assemblies and condenser bodies back to the battery neg terminal.

Dunno what meter you have but setting the meter to its
lowest resistance range and noting the reading when you short the probes together before testing will help you see how good the ground continuity is.
Ideally I'd want to see less than 1 Ohm from any ground point to battery neg

One quick and dirty cap test is to disconnect the caps from the points
and measure the voltage from the terminal to the body
if they vary ( even if they dont) ground each one to the base plate
for a second or two to get them, both at the same potential.

Then do a resistance check from terminal to body which applies a small voltage to them
and quickly switch to voltage to see if they both have roughly the same voltage.
As I said quick&dirty plus too many variables to get any conclusive results, but it may show up significant variations between the 'good'
and new condenser.

Re Pepperami's post
A diode test on the RR wont hurt.
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bikers smell of wee

[bikenut]

Some dmm's have capacitance measurement function...

Compare one with the other...

Do your capacitors have a yellow wire and a black wire ?

Post a picture of the points area...
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nuts about bikes

[A100man]

Fired it up again this morning and it's running nicely. The retrofit reg/rec I fitted lat years also seems to be working as I'm going from 12.5 up to 13-14 with a few revs (the original GT250 only has a rec no reg...)..

Couldn't see much arcing either during running but I can when I test it 'statically' opening the points with my thumb and check for spark with a spare plug.

To wire up the beetle condenser I had to common the single green wire to both points and source. I'll order a proper replacement anyway. Will re-read WDs post to see if I can understand the check procedure too

TTFN
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Now: A100, GT250A, XJ598, FZ750

Then: Fizz, RS200, KL250, XJ550, Laverda Alpina, XJ600, FZS600

[bikenut]

You do realise there should be 2 condensers/ capacitors, one for each set of points, 2 seperate indipendent systems but with a common 12v to the ignition coils ?
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nuts about bikes

[A100man]

[Islander]