Mk1 Ignition system

[Adrian Dale]

need a bit of advice:
I have a very intermittent spark on my recently overhauled FV. Actual symptom is that with one pull a spark is delivered just once, from then on, with the remaining rotations, it is not strong enough to register. If the rope is wound back on and another crank is given immediately, no further spark is seen, but if the time between cranks is left for 10 minutes of so, one more spark will be the reward!
The following has been checked:
Points.. Replaced, New
HT lead.. Replaced, New
Spark plug.. Replaced, New
Coil.. Continuity check, ohms 3k Checked against new coil and as recommended on the main site
Magnetism ok (tried the old drill trick)
Condensor.. Have ordered a new spare direct from Villersparts.co.uk (not yet delivered)
Cables and soldered joints checked for continuity.

Any suggestion where to go from here? My guess is the condensor but it will take a couple of weeks for delivery. I have fully functioning Mk1 systems on both an LS, and 102 but don't want to disturb them to test the FV. Definitely do not want to put a Mk2 on.
AJ


AJ

[1charan]

Your condensor is dying, with every pull you are getting it closer to death. So yes, replace the condensor.

[headdownarseup]

thats interesting
i have a similar problem on a 102 i'm playing with.
same symptoms, very weak spark.

jon

[Gannet]

A very interesting topic.
Apart from a poor spark, how can one determine whether the condenser is the culprit? In other words, how does one test a condenser?
I have tried two methods, but am completely confused what the results mean:-
1. Connected a analogue ohm meter across the condenser and observed the resistance slowly decrease from infinity to 1kohm on one condenser and to 500ohm on another. I would have guessed from that result, that both were functional. Is that correct?
2. Connected a 1.5v battery across each condenser whilst observing the voltage on an anologue voltmeter. The voltage went up to 1.4v and then when the battery was disconnected the voltage dropped down to zero very quickly ( ie at the normal needle speed). I would guess this indicates that the condenser doesn't hold charge and is therefore defective. Or am I not measuring the rate of decay accurately enough? Any comments?

Hopefully, somebody, unlike myself, with proper electrical expertise will advise.
Thanks.
Jeremy

[headdownarseup]

thats a very good point JEREMY
ignition coils are fairly easy to check whether alive or dead?
but condensers are something else.
i've always wanted to know if there is a simpler way of testing a condenser as well.

can anybody shed some light!

jon

[Adrian Dale]

When I get the new one I will do some testing to compare results. however, I do not think a 12v battery will give anything of value with the voltage so low. Like you, I have not found any info on testing. That is why after testing or replacing each other single part of the system I came to the conclusion, by process of elimination, the condensor has failed.

be really interesting to find a sure fire way of confirming status of the condensor

AJ

[Keith.P]

As its basically a capacitor, its tested in the same way as a capacitor.
Seems easy enough.

https://www.youtube.com/watch?v=FxD1OpPQaS0


http://www.ehow.co.uk/how_5526059_test- ... ngine.html

[Adrian Dale]

This is the method from one of Keith's email searches copied and pasted below: Thanks Keith for this insight

Instructions

1) Remove the condenser from the engine. Place the condenser on an insulated wooden surface such as a workbench. A metal surface may cause the test to fail. You will note that there is a small metal connector located at the top of the condenser. This connector is the "hot" or power connection. The metal case of the condenser is the ground point.

2) Switch the volt ohmmeter to the ohms position. Place the red lead into the "ohm" connector on the meter. Insert the black lead into the "com" or common connector on the meter.

3) Touch the red lead to the hot connector on the condenser. Place the black lead to the metal case or ground point on the condenser. The meter's deflection needle should have jumped slightly to the right. The needle may also slowly rise in the right hand direction. Hold the leads in place for 15 seconds to 20 seconds. This action places charge to the condenser.

4) Remove the leads and reverse the placement to the condenser. In other words, move the red lead from the hot connector to the metal case, and move the black lead from the metal case to the hot connector. At the moment where both leads are touching the correct points, the meter should jump towards the right. This action discharges the condenser.

5) Movement from the meter's needle indicates the condenser is good. If no movement was indicated on the meter in either circumstance in Step 3 or Step 4, the condenser is bad and must be replaced. Retest the condenser several times for a consistent reading.

[Michael]

If you are interested there was an article in the Antique Oatboarder in July 1991 that described how to build one. Everything could be found at a Radio Shack in the USA. I did build one in about 1992 and have used it ever since - it does work. I can't seem to load it here, so if anyone wants a copy, PM me and I will email it too you.

[haventaclue]

PM sent

[Adrian Dale]

Checked the condenser as per Keith above ... It dead, now waiting new coil

Thanks Keith

AJ

[Keith.P]

Its strange that the condenser being a vital part of the ignition system is always the last thing that gets tested.
Probably because its not a common item to fail, its an out of sight, out of mind type of part.
Never found a dead one, not on a seagull anyway, but it would still be the last of the ignition system I would look at.

[Adrian Dale]

an update on the original post re the Mk1 Ignition system on the FV. The condenser finally arrived yesterday from Villiers and was fitted this afternoon. Result; excellent spark by simply spinning by hand. So after replacing everything else the culprit was the condenser. The FV, from being a basket case with both gearbox and cylinder seized plus a duff ignition, is now nearing completion. Another old engine saved looking forward to a trip on in the D'entrecastuex Channel.

So if you are having a problem with the Mk1's and have tried the usual suspects check the condenser it could be your problem too

AJ

[Gannet]

Well done Adrian,

Its nice to know that there is another FV in good working order.
As you know your FV1580 is a very old one, and once it has had that trip on your dinghy will probably be the oldest FV to have been used in earnest this year.

Do condensers progressively loose performance? In other words would the spark get weaker as the condenser starts to fail? Or is it a matter that the condensers functions tp enable the system to produce a good fat spark or has failed so that there is no spark?

Jeremy

[denchen]

Condensers used to be a wrap of alloy film rolled up tight with a layer of brown paper to separate each roll and ensure the foil does not touch the metal case. An engine should run for a while with the condenser disconnected, but the point would soon blacken and burn. So if the condenser is suspect a quick test is to run the engine without the condenser connected, but only for a short test or you will want new points.