testing ignition pickups

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spaz
Posts: 22
Joined: Fri Apr 28, 2006 12:00 am
model: 750 Paso
year: 1987
Location: Osceola, Indiana

testing ignition pickups

Post by spaz »

I finally got the pickups from Electrix and installed them, problem is that it still will not start. I'm going through everything to make sure it all works but how do you test the pickups, thanks.
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paso750
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Re: testing ignition pickups

Post by paso750 »

just check the workshop manual.
It says there (p. M.14) to measure the resistance which should be 220 ohms +/- 5%.

G.
spaz
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Re: testing ignition pickups

Post by spaz »

ok, G so I know what they should be but how do I do it?
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paso750
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Re: testing ignition pickups

Post by paso750 »

as mentioned in the Haynes manual (ignition section) that you also find in the downloads you disconnect the two pin connector from one ignition box. Then you set your ohm-/multimeter to ohms x100 scale and measure between the two cables red and white. Write down the value, reconnect and then do the same with the other connection on the second ignition module (by memory it should have a black and yellow wire).
Values should be the same on both pick ups.

Interesting btw that the Haynes manual for Supersport/Monster says they should have 95-105 ohms which is quite a difference to what the Paso manual says which makes me wonder as all shops sell the pick ups to fit all carbed belt driven Ducs. Was the resistance reduced to gain a stronger signal, anyone know ?

G.
angelix
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Re: testing ignition pickups

Post by angelix »

pickups can be tricky, but they are very simple devices the either work or don't.

the distance from the flywheel is VERY important, you will need to checvk this carefully; sometimes 1/10 mm is more than enought to cause problems.

another thing is the way they are connected, I never tried, but I was told that if you swap the wires (polarity inversion) the pickup will not send the right signal to the ECO/MODULE.

Another issue is that the you need to be carefule in connecting the right pickup to the right module, by inverting them its a SURE non starter.


My suggestion is to remove one plug, tghe fuel tank and see if you can drain the fuel from the carbs.

then with ONE PLUG ONLY start checking if you have spark and see if you can start it by squeesing some fuel directly into the the carb mouth (only the cilinder with the spark plug)

this system will allow you to focus on ONE pckup and ONE set of casbles at the time and by using a small syringe of petrol you can also be sure you are not flooding the engine.

if the cooections are correct the engine should start straight away on one cilinder and run for 3-5 seconds.

once one Cilinder is done you do the same with the other.

It is a little bit tedious, but this was the way I sorted mine and it took only 30 minutes in the end...

NOTE: with an IGNITECH ECU the software will tell if the pickup are working and allows to invert polarity and swap pickups without touching the engine.
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paso750
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Re: testing ignition pickups

Post by paso750 »

but I was told that if you swap the wires (polarity inversion) the pickup will not send the right signal to the ECO/MODULE.
How would that be possible ? The connector fits only in one direction.

G.
angelix
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Re: testing ignition pickups

Post by angelix »

paso750 wrote:
but I was told that if you swap the wires (polarity inversion) the pickup will not send the right signal to the ECO/MODULE.
How would that be possible ? The connector fits only in one direction.

G.

very simple: the pickup cables have to go through a small hole in the crankcase and to be able to do so, you need to have the cables (and related fastons) separated from the connector as the connector(s) is too big; I think that if you check a haynes or a Ducati workshoop manual there will be the procedure of how to remove the connectors from the cables (without damaging them) explained

basically whenever you disassemble the original pickups you NEED to mark which way the connector goes in relation to the pickup cables

with brand new pickups you do not have this markings (cable colors do bot really tell which way they need to go) , therefore you will need to either "be lucky" or go "trial and error".
spaz
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Re: testing ignition pickups

Post by spaz »

You can tell by the color of the wire, also on mine one set was longer than the other.
jayh
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Re: testing ignition pickups

Post by jayh »

Also heat / oil damage to the wires requires new silicone heat resistant wiring be fitted to avoid shorting .If this has been done previously ,odds are that the wires are all the same colour ,very easy to mix them up :oops: :oops: :oops: . J.
Mc tool
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Re: testing ignition pickups

Post by Mc tool »

Why not just hook up your timing light to one plug lead, point it at the timing window and see if the correct timing marks show up when it fires, just swap the spark plug leads over from one pot to the other if it aint right
I wish I was young again............Id be heaps smarter than last time
spaz
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Joined: Fri Apr 28, 2006 12:00 am
model: 750 Paso
year: 1987
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Re: testing ignition pickups

Post by spaz »

So, for the sake of argument lets say you're not an Engineer nor do you have a timing light that you are just a rider forced to be a mechanic. How do resolve the issue?
angelix
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Re: testing ignition pickups

Post by angelix »

spaz wrote:So, for the sake of argument lets say you're not an Engineer nor do you have a timing light that you are just a rider forced to be a mechanic. How do resolve the issue?
I already posted "my" system in this thread.

basically you need to do one cylinder at the time; by doing this way you only have ONE set of cables that can go one way or another.

As I already mentioned before, it seems that inverting the polarity could cause issues.

on the pickup plate it should be indicated the correspondece with the cylinders, therefore that part is fairly easy to sort out although you will need to remove the cover on that side.

then there is the polarity, at this point you do one cylinder at the time, leaving the other unplugged and test if it starts and runs well on one cylinder only; by feeding the fuel with a small syringe directly in the carburators mouth you can make sure the engine is not flooded.

once one cylinder is sorted, you do the other; the whole procedure will take 30 minutes at most.
bobst2
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year: 1988
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Re: testing ignition pickups

Post by bobst2 »

i used a snap on vantage to test my pick up coil it showed ohms and a pattern.
strangle enough my 88 paso only uses one pickup coil . i am haveing some trouble
with the ignition dropping a cylender after it totaly warms up the front/horizontal
cylender looses spark.
i found a source for new marelli digiplex boxes.i ordered a couple & a spare coil
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higgy
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Re: testing ignition pickups

Post by higgy »

Most frequently dropped cylinders are loose or poor connections,don't forget the spark plug wires, very common and can be hard to trace when intermintent. Vacuum leaks at the carbs can also cause dropped cylinders sometimes using the choke can help pin it down if it improves with the choke on. Marrelli Ignitions don't generally go bad on their own, poor grounds will fry them quickly so make sure you track down the cause before you put it a replacement :beer:
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bobst2
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Joined: Sun Jul 24, 2011 1:57 pm
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year: 1988
Location: delta b.c. canada

Re: testing ignition pickups

Post by bobst2 »

i did go through the whole bike servicing all grounds and connections i am going to go for an extended test ride today.the worst two connections were where the battery & engine cable meet on the frame & out front at the starter.
this seems to of helped correct charging voltage rates & starter speed.
i will post results.
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