Geoclinton Posted December 4, 2011 Share Posted December 4, 2011 Hi guys Q1 Just been out on the mx lost power after erratic running now no spark can any one post the simplest wiring diagram to see if i can get her going.? Q2 The wiring into the magneto/engine casing has some severed wires so I am looking at replacing them in order to put on my new loom Do I have to send the whole magneto unit away to have the wires solderd on or is there a simpler solution? Cheers Geo Link to comment Share on other sites More sharing options...
Moderator Airhead Posted December 4, 2011 Moderator Share Posted December 4, 2011 I too have some questions Did you get the old girl an MOT then? dont remember you saying? its been pissing it down all day here, how about in Brighton? How many wires does your CDI have Geo ? What about those severed wires, how did that happen...what colour are they? Link to comment Share on other sites More sharing options...
Geoclinton Posted December 4, 2011 Author Share Posted December 4, 2011 Yep through the mot thanks to a donor bike Nope not a drop of rain 7 wires through to the cdi the severed wires looks like they have come about due to a lack of care from the previous owner the colors are yellow/ sky blue /white & red /brown/ black and green there are 3 left connected I am just a little concerned about how hard replacing these wires will be. Any ideas? Link to comment Share on other sites More sharing options...
Moderator Airhead Posted December 4, 2011 Moderator Share Posted December 4, 2011 i suppose the easiest way would be to repair them and then cover them with adhesive lines heat shrink individually and then tape up the bundle. I am totally confused with your last post though because your bike wouldnt have run at all with some of those wires severed for example the white/red, Brown, Black Read this DT175MX Ignition checks There were two versions of ignition systems on DT175MX bikes. The mk1 version from the earlier bike had a 7 wire CDI the early bikes had a round section swing arm. The mk2 version had a 6 wire CDI, the red wire is absent on these. These bikes have a square section swing arm. The HT cap (AKA spark plug cap) unscrew it off the HT lead, it is supposed to be a resistor cap so should be around 5K Ohms The ignition coil primary...Orange wire to battery neg should be 1 Ohm +- 10% The ignition coil secondary...HT lead to battery neg should be 5900 Ohms +- 20% If the readings are much higher, check the ignition coil has a clean ground connection. Yes and the ignition coil mounting is a wiring harness ground point too, so check its clean and bright there. Disconnect all the wires from the CDI. Then using your multimeter on the loom side of the connectors. Black probe on a clean part of HT coil ground point Red probe on...... Orange, Meter to 200 Ohms, expect 1 Ohm (HT coil primary) Brown, Meter to 2k Ohms, expect 420 Ohms for mk1 and 300 Ohms for mk2 (Magneto charge coil) White/Red, Meter to 200 Ohms, expect 12.4 Ohms for mk1 and 10 Ohms for mk2 (Magneto pulser coil) Red, Meter to 200 Ohms, expect 13.6 Ohms for mk1 only. (Source coil 2 or high speed coil) Black female connector, Meter to 200 Ohms, expect dead short repeat for black male connector Any difference in the results for the two black wires may possibly be rectified by cleaning the front engine mounting bolt and a little of the frame behind the bolt head, then tighten to torque spec. Black/White, Meter to 20K Ohms, with ignition off expect dead short, with key on expect open circuit, with kill operated expect dead short (Engine kill operation) Link to comment Share on other sites More sharing options...
Geoclinton Posted December 4, 2011 Author Share Posted December 4, 2011 Thanks O G I will be purchasing a volt meter tomorrow and testing from your post figures. The wires remaining I assume to be the necessary wires for the bike just to function so I do have to reinstate the internal wiring from the magneto only problem being I am not sure I will be able to retrieve them in order to be fixable good thinking though! Cheers Geo Link to comment Share on other sites More sharing options...
Moderator Airhead Posted December 4, 2011 Moderator Share Posted December 4, 2011 but how can it run with the white/red and brown severed? these are pulser and charge coil wires for ignition Link to comment Share on other sites More sharing options...
Geoclinton Posted December 4, 2011 Author Share Posted December 4, 2011 The colors I gave you where of all the wires that head towards the magneto the guy who had it before me ran the bike on his own wiring so I am now in this position where I have to fit a new loom and reinstate the original electrical plan hence my concern about the magneto wiring Link to comment Share on other sites More sharing options...
Moderator Airhead Posted December 4, 2011 Moderator Share Posted December 4, 2011 heck geo getting info out of you is like trying to get blood out of a stone man! now i see its been rewired somewhere, so you want to rewire it with the right colours (big job) or just get it going again (smaller job) ? Link to comment Share on other sites More sharing options...
Geoclinton Posted December 4, 2011 Author Share Posted December 4, 2011 Well first off I would like to get her going so simple wiring, then once I am happy that she runs ok the I will fit the new loom. Soz that I am not fully open with the info will try harder next time Cheers Geo Link to comment Share on other sites More sharing options...
Moderator Airhead Posted December 4, 2011 Moderator Share Posted December 4, 2011 so then with a 7 wire CDI you would normally have 4 wires to run, yet yours has only 3, I suspect you have a chassis ground wire missing here!...black label your 3 wires a,b, and c disconnect these wires and using the multimeter take resistance readings of these wires to an engine case screw and report back the readings Link to comment Share on other sites More sharing options...
Moderator Cynic Posted December 5, 2011 Moderator Share Posted December 5, 2011 Where has the donor bike gone in all of this? Or was the donor bike's reg plate the only component swapped I take it you were running without lights, including the brake light too as there would be no charging either. Sounds wierd. Link to comment Share on other sites More sharing options...
Geoclinton Posted December 5, 2011 Author Share Posted December 5, 2011 Cynic the donor bike is in bits I used the panels barrel. piston, lights, kickstart, stand, among-st other things. I am only a novice at this but would recommend having a spare bike its like havin a shop in your shed full of spares. The electrics on my bike where at a bare minimum with the coil,rectifier and cdi unit all under the tank I ran the lighting direct of the battery(without the charge) with a fuse built into the circuit.Now I want to fit a new loom and have reached the conundrum of the severed wires at the engine casing any advice would be appreciated as I am a bit worried that I will not be able to sort it as the wire ends are just visible from the top and it looks like there isnt much room in there to attach new wires onto them. Weirdness explained? O G I have ordered a multimeter so once I have it I will take the readings and get back to you Cheers Geo Link to comment Share on other sites More sharing options...
Seana23 Posted December 6, 2011 Share Posted December 6, 2011 Bring her over and i'll give her a tickle for you. XXX Link to comment Share on other sites More sharing options...
Moderator Cynic Posted December 6, 2011 Moderator Share Posted December 6, 2011 Thats a nasty mix. Trouble is new looms aren't as complete as you might hope. There will be little sub looms and connectors that may or may not be in there too. Diagrams are not brilliant for that either, its a case of knowing what you do and don't need. As to the donor question its not unknown, positively common place with Land Rovers. The one good point is that if you remove the mag entirely there is plenty of meat to fix new wires to, i have done it with mine. Link to comment Share on other sites More sharing options...
Geoclinton Posted December 6, 2011 Author Share Posted December 6, 2011 Col thanks for that The new loom has all the wires matching to the drawing we think! So here's hoping Its good to know the mag has plenty to work with that brings peace of mind Will let you know the outcome if there ever is one!!! Cheers for the offer of a tickle seanna maybe Friedee ? Cheers Geo Link to comment Share on other sites More sharing options...
Seana23 Posted December 9, 2011 Share Posted December 9, 2011 Space has been made next to Janas 535 in the back-livingroom... and my Big Hammer is dusted and ready ....! see ya Friday evenin. X Link to comment Share on other sites More sharing options...
Seana23 Posted December 10, 2011 Share Posted December 10, 2011 Ok, so now ive got her, you need to bring the battery charger, any wiring bits, including loose wires and the switchgear off the old bike, the little rectifier off the old frame, under the seat. Oh and ya manual. thanx X Link to comment Share on other sites More sharing options...
Moderator DirtyDT Posted December 10, 2011 Moderator Share Posted December 10, 2011 7 wire CDI's Brown, Red White/Red, Black from the stator to the CDI matching coloured wires. From the CDI it was; Black/White, Black, Orange Orange to the coil Black looped back to the Black input and earth Black/White was the engine cut off so if not connected to anything the engine runs and if earthed the engine stops or won't start. It is important that the coil, CDI and stator are properly earthed. The other wires from the stator are light blue - Neutral light - earth really Green/White - which goes to the rectifier and MAY change to White only in the loom Yellow - goes to power the lights These last 3 are not required for the bike to start and are lights charging use only. No battery is required to run them. Link to comment Share on other sites More sharing options...
Moderator DirtyDT Posted December 10, 2011 Moderator Share Posted December 10, 2011 Link to comment Share on other sites More sharing options...
Geoclinton Posted December 10, 2011 Author Share Posted December 10, 2011 Nice one Dirty Thanks for takin the time to do that Ye be a star !!! Link to comment Share on other sites More sharing options...
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