magneto ,no spark

admin

1-Got my welder done up ( painted, new gasket, wired ) ,but now the thing wont spark at the plug,it was running good till i took it apart and re-wired the thing ( LOL ). My question is, the wire going to the side of the magnito ,is connected to a switch that connect to ground,so if i understand this write, when switch is on it grounds the magnito and the engine will stop as you cut the power to the points sort of speaking by shorting it.2-got the cap off  to where i see the points,now by turning the engine should i see some spark at the point , or is there some way to test if power is going to the points or out of the coil, so i can try to pin-point the problem.3- the oil pressure switch ,when you crank the engine, is there enough pressure to make them work or does the engine have to run,cocomunkLast edited by cocomunk; 10-16-2010 at 07:22 PM.
Reply:if the points spark it has a bad condenser.  Points don't spark except on HF TiG units.
Reply:Thanks, no spark at point, now is there a way to know if there is current going to the point, can this be check with a test light while crancking.cocomunk
Reply:1 - Yes the switch grounds the points (coil actually) so that it's as if the points never open (at the appropriate time) to allow the magnetic field in the coil primary to collapse as it normally does.Did you do anything to the mag like change points and condenser or take it apart?  Are the points set correctly at .015" +/-.002" at high cam?2 - A good operating mag will generally jump spark from the coil tab to the mag housing when turning by hand or cranking.  Or you can short a screwdriver to the housing and hold the tip 1/4" from the coil tab and it should jump a good spark.  Keep the screwdriver shorted to the housing or you'll get a good jolt! 3 - Cranking speed is typically sufficient to close the OP switch if the oil pump and bearing clearances are up to snuff.  If not, it could be the switch set point is higher than it needs to be.  A 4psi switch is usually used as 7psi is the minimum idle speed oil pressure for the F162/163.MM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!
Reply:1. Switch in the "On" position?2. Is the bolt that comes out of the magneto grounded against the magneto on accident? I had one where the insulator was missing and the little bolt was grounded so it wasn't getting any spark to the plug.http://www.facebook.com/groups/sa200weldersCurrent machines:Hobart G600 Powered by 1967 Chrysler LH-318 (Project)Hobart GF-250(Traded)68 Redface81 Blackface
Reply:switch on meaning it is making contact, but duaneb55  answer what i needed to know.I did check the insulator and it is fine,it is not grounding to the casing, thanks for the advise though.duaneb55 when you say the coil tab , are you talking about the flat piece comming out of the coil that contact with the lead rod going to the distributor rotorand no i did not touch the magnito at all on the rebuilt.  Could the condenser be de-ernergise ???? just a question in the air for that one,as i know they can keep a good jolt when you grab them . lol.thanksLast edited by cocomunk; 10-16-2010 at 09:32 PM.
Reply:Most all mags work on an impluse principle, that is, the internal mechanism operates on an over center principle where the armature passes quickly enough through the field during startup, to produce the voltage needed to jump the spark gap at the plug.  If you didn't disassemble the mag, then it's timed incorrectly.  Does the mag have a drive gear or does it have a tang at the driven end?  If it's a tang, it's probably 180 degrees out of sync,  If it's a gear drive, you'll need to time the mag to the engine.  A good place to start is setting the engine to TDC (on the firing stroke with both valves closed and play in both valve actuators).  Most engines have TDC marks on the flywheel but you need to ascertain what stroke the engine is on.  4 stroke engines are just that, intake stroke, where the piston falls and the intake valve opens allowing a fresh charge in, compression stroke, where the engine compresses the charge and at or just before TDC, the charge is ignited by the spark and drives the piston sownwatd and the exhaust stroke where the piston rises and expells the spent charge.  The piston then falls and the process is repeated.You need to set the engine on the compression stroke, at TDC and then install the MAG, with the timing marks on the MAG directly across from each other, or the points just starting to open.The physical relationship of the MAG to the timing gears is everything.You can ascertain if the MAG is operating correctly by grasping the mag on your hand and rotating the drive gear until you feel resistance.  At that point the MAG is just starting into the over center position or impulse position where the internal mechanism will rotate the armature as a speed fast enough to generate the current needed to spark the plug(s).  Just put your finger in the HT plug on the cap and keep turning.  If it knocks you on your butt, all is well.  if not, either ther points are set incorrectly or the condenser is bad.  The impulse mechanism is foolproof, well, almost.  If you took the MAG apart (big no-no) you might have problems getting the springs and weights back together again without a specific manual/diagram.Finally, if the MAG has a helical gear drive, timing is even more difficult because as you seat the MAG in the timing gear casting, the helical gear will advance or retard (depending on the gear cut) the timing.  In that case, the most important tool is a shop manual with the proper insertion schematic.  The engine builder has already determined how many teeth the drive gear must be advanced (or retarded) to allow insertion and final position to be at the proper timing sequence.
Reply:played with it this morning and magnito does spark from  coil tab to the mag housing, good news for me lol. Now will check the rest one by one, the point had some built-up on it, clean it off and adjusted the point , look to be sitting at  .018 ,so it should be good,now time to put her back together and give it another try.cocomunk   Thanks
Reply:Big thing on these mags is the oil seal, if it leaks there is an oil mist in the mag itself and won't fire. So if you happen to see oil in the mag, and clean it, as soon as the engine spins over, the oil will reappear in the mag.
Reply:Properly setting the mag for initial timing is quite simple and takes just a couple minutes to do once familiar with the process.Continental L-Head Magneto Timing.pdfAnd of course here's Lincolns offering on the subject:http://content.lincolnelectric.com/p..._IMS/IM179.pdfIf - when properly install - you still don't get spark at the plugs, it may be due to a crack in the cap allowing spark to travel to the mag housing (ground) rather than out the wires to the plugs.MM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!