Johnny Posted November 28, 2011 Report Share Posted November 28, 2011 Ok, what am I doing wrong? I think I've been away too long from Bultos racing 4 strokes with electronic ignition. I've rigged up a lamp and buzzer to test the ignition timing on the M80 I am rebuilding. There are 3 wires from the magneto. Black, green and yellow. I assume yellow is from the lighting coil and so I've blanked it off. I've connected black to the coil and green to a good earth. To test the timing I've attached one lead from the tester to the black wire which I've disonnected from the coil, and the other lead to earth. I've set the piston at TDC and rotated backwards towards 2.9mm BTDC. Problem is the light doesn't go out when the points open, which I thought it should. Have I got it wrong? Quote Link to comment Share on other sites More sharing options...
pschrauber Posted November 28, 2011 Report Share Posted November 28, 2011 Ok, what am I doing wrong? I think I've been away too long from Bultos racing 4 strokes with electronic ignition. I've rigged up a lamp and buzzer to test the ignition timing on the M80 I am rebuilding. There are 3 wires from the magneto. Black, green and yellow. I assume yellow is from the lighting coil and so I've blanked it off. I've connected black to the coil and green to a good earth. To test the timing I've attached one lead from the tester to the black wire which I've disonnected from the coil, and the other lead to earth. I've set the piston at TDC and rotated backwards towards 2.9mm BTDC. Problem is the light doesn't go out when the points open, which I thought it should. Have I got it wrong? Don't think so? 1 white, 2 kill button, 3 red from stator, 4 coil ground,earth 5 plug 6 coil 7 green from stator 8 black from stator 9 yellow 10 stator You might check your electrical cables and devices. Quote Link to comment Share on other sites More sharing options...
woody Posted November 28, 2011 Report Share Posted November 28, 2011 (edited) Ok, what am I doing wrong? I think I've been away too long from Bultos racing 4 strokes with electronic ignition. I've rigged up a lamp and buzzer to test the ignition timing on the M80 I am rebuilding. There are 3 wires from the magneto. Black, green and yellow. I assume yellow is from the lighting coil and so I've blanked it off. I've connected black to the coil and green to a good earth. To test the timing I've attached one lead from the tester to the black wire which I've disonnected from the coil, and the other lead to earth. I've set the piston at TDC and rotated backwards towards 2.9mm BTDC. Problem is the light doesn't go out when the points open, which I thought it should. Have I got it wrong? Electrics aren't my best subject (can't understand what I can't see, no moving parts etc...) but don't you have to disconnect the wire from the points when you use the buzzer/light technique, otherwise there is a constant circuit? I'm not sure where the leads from your tester connect though. However, you have the colours correct, black to coil, green to earth. As you can guess from my answer, I use the strip of paper between the points instead. Pull it taught and tension it whilst it is held with the points closed, rotate flywheel and as soon as the paper slides free, they're opening. A lot easier. Edited November 28, 2011 by Woody Quote Link to comment Share on other sites More sharing options...
pschrauber Posted November 28, 2011 Report Share Posted November 28, 2011 Disconnection of cables to the pionts, never done, seen or heard? The places where you tried to connect the lamp are OK, like the workshop manual if this might please you. BTW: Before adjusting the timing, be sure that you have the right distance between the points, should be 0,4mm exactly. The points should be fresh, not worn, no residue between them, if you have any doubts use a points file*: *not sure about the right expression in English The Lamp should burn as long as the contacts are closed. Much easier are beeper in use, as you can better focus your eyes to the scale for measuring the TDC. Many multimeter have this feature, (mostly not known). Quote Link to comment Share on other sites More sharing options...
copemech Posted November 29, 2011 Report Share Posted November 29, 2011 Depending upon your tester arrangement, things may not work with the capacitor in circuit. Disconnect it while setting and the points should then break the light and buzzer. Quote Link to comment Share on other sites More sharing options...
mrb505 Posted November 29, 2011 Report Share Posted November 29, 2011 You have to disconnect the green earth from the frame With a ohm meter I connect black to one wire from the meter, the other wire from the meter to a good earth point, eg cylinder head, my ohm meter has a buzzer as well which makes it easy, I'd say your tester with the light would work much the same. Its something to do with the earth leaking back through the l/t coil or whatever, its a mystery Quote Link to comment Share on other sites More sharing options...
Johnny Posted November 29, 2011 Author Report Share Posted November 29, 2011 Points and condensor are both new and points are gapped correctly. I agree, the fag paper method is easier but I had the bits in the garage to make the light and buzzer set up so I thought I'd use that method. Just need to use it properly! I will try disconnecting the green earth wire when I get time later. Thanks for the suggestions. Quote Link to comment Share on other sites More sharing options...
nigel dabster Posted November 29, 2011 Report Share Posted November 29, 2011 Yes cant remember why but disconnect the green too. I always prefer to set the timing by points adjustment because you get it spot on easily, would never worry about .4mm gap Quote Link to comment Share on other sites More sharing options...
Johnny Posted November 29, 2011 Author Report Share Posted November 29, 2011 Yep, you're right. Disconnect the green wire and it works. No idea why though. Cheers. Quote Link to comment Share on other sites More sharing options...
smelling123 Posted November 29, 2011 Report Share Posted November 29, 2011 Yep, you're right. Disconnect the green wire and it works. No idea why though. Cheers. As mrb505 says, the test will feed through the low tension side of the coil to earth so the tes wont work unless you remove the coil wire. Glad you sorted it. Quote Link to comment Share on other sites More sharing options...
pschrauber Posted December 3, 2011 Report Share Posted December 3, 2011 As mrb505 says, the test will feed through the low tension side of the coil to earth so the tes wont work unless you remove the coil wire. Glad you sorted it. This is a very interesting information to me as it worked without disconnecting the coil wire? Today working a little bit around in the garage for the bul I tried again and it worked. This made me curios why as the explanation sounds very convincingly. looked to my two electrical devices that I use for adjusting the ignition: An electronical multimeter with an automatic range selection and my contemporary Motoplat "Aparato puesta punto sonoro" which I bought in 1981 for adjust the ignition. I found out that there are some electronical devices inside, the unit making the buzzing sound is in the right, then thee are some resistance units a adjusting device and a condenser. in the middle is a logical unit made by TI (Texas Instruments) too. The backside is by the way the operation manual, stating on Spanish just to place the clamps on mass and where the point/ignition are connected. only thing that has to be done extra is to disconnect any battery devices. Then I took a look in the manual of the multitester: The manual reports that this device detects measuring values of approx. < 10Ω for the troughput and permanent signal sound. No I understand! A normal bulb or buzzer and batterie electric circuit connected to the ignition will not work proper because of the remaining coil as this coil consumes too much electricity. When the coil is disconnected this consumer of electricity is off and you can detect the closing or opening of the points as there are enough electricity avalable to light the bulb or operating the buzzer. While the other devices mentioned are measuring the resistance and any difference detected will affect the operation of their buzzers. Anyway thanks for the information, good to know if you are on a journey and don't have them with you. Quote Link to comment Share on other sites More sharing options...
Johnny Posted December 4, 2011 Author Report Share Posted December 4, 2011 Must have got it right! Once I'd sorted out the carb it started easily. First time I've started a Bulto since 1978! Looking forward to riding it now but there are a few other jobs to finish off first. Thanks for the help. Quote Link to comment Share on other sites More sharing options...
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