Hi
I recently bought and am in the process of trying to ressurect a 1978 Darmah that has been standing for 10 years.I managed to get her started and ran very roughly for a while then would only run on one cylinder.There seems to be an intermittant spark on the rear cylinder.Could be a number of things but having read a number of threads on here about pick up wiring i decided to check mine.The wire from the pick ups is bare copper wire for the first 3mm then each wire is covered by a loose fitting black plastic/rubber sleeve.The 4 sleeves then exit the gland nut and up to the Bosch boxes.There is no sign of the original wiring insulation of white and white/black except near the Bosch boxes where the wires are spliced.So it looks like someone has already tried to fix the usual problem.My question is whether this is likely to fix the usual problem or if it is necessary for some shrink wrap near to the pick ups to stop oil coming in contact with the bare copper wire?Does oil conduct electricity?Sorry if these are silly questions but electrics mystify me!
Pick ups
pick ups
Don`t feel bad Splanchio. Oil AND electricity mystify me!!! How they can work together like they do on a duc I don`t know. Just look at the alternator, why does`nt the windings short out through the oil?? Maybe the slinging effect of roatry motion........But I digress. All i can say is that if it were mine I would leave no copper wire uncovered and would be inclined to give all wires a nice snug coat of shrink fit and maybe a little smear of RTV silicone at each end. Not much, just a touch. Cheap insurance I rekon, even if the problem lays further afeild.
The insulation on my wires all turned to poop inside the rubber sleeve that goes through the gland nut. Externally all looked peachy keen but internally the insulation was a pulpy consistancy and the electrickary was jumping from wire to wire at will.
I left about 1" of wire out the pick up and spliced new wire and covered with shrink fit. Mind you the wire out of the pick up on mine was still in very good nick.
The insulation on my wires all turned to poop inside the rubber sleeve that goes through the gland nut. Externally all looked peachy keen but internally the insulation was a pulpy consistancy and the electrickary was jumping from wire to wire at will.
I left about 1" of wire out the pick up and spliced new wire and covered with shrink fit. Mind you the wire out of the pick up on mine was still in very good nick.
The oil itself won't cause arcing/shorting. Oil is an insulator unless it is very heavily contaminated with metal and at that point ign. would be the least of your worries.Checking the resistance of the pickups would be the place to start.IIRC they should be about 220 ohms.The important thing to check is that there is no continuity between the wires and ground and also between the wires of one pickup to the other.If there is it would indicate a short between the wires somewhere along the line from the pickups to the transducers.If there is a short my guess would be at the gland nut area as described by Lumpy.If that area is ok take a good look at the carbs and the manifold rubbers as vacuum leaks and plugged jets will have you barking up most of the trees in the forest.Anything that sits for 10yrs. will have more than one thing wrong especially if you don't know why it was parked in the first place.