I have a 1975 Dt250b that I am trying to get firing. The PO pulled the source coil but before that he said it ran. My question is how do I correctly hook the coil back up. A black wire is coming out of the bottom of the coil and it looks like the top wire clip from copper wire wrap is missing a wire. My next question is under the lighting coil is a thin brown wire that is disconnected, where is the home for this? Ive attached some pictures below. Any help would be greatly appreciated.

Hi CaptCove, ironically I was solving a problem that will help you, only last week when upgrading my lighting coil to 12v. Some of the DT250B source coils were earthed via a few 'extra windings' wound on to the lighting coil. You don't need the cross connection wire, so what you need to do is simply cut this wire where it feeds into the lighting coil to tidy that side. On the source coil that frayed wire clamped to the paxilin former its wound on needs to have some of its varnish scraped off and solder a small extention wire on so you can put an eyelet on it and earth it down via the source coil fixing screw right next to it. Next, that black wire coming up from the source coil and unconnected to anything in your pics should be connected to the big blob of solder on the condenser (i.e. so three wires actually connect through the blob to the condenser. Don't get any of that solder blob shorting over to the earthed condenser casing though. (Before soldering the black wire its an opportunity for you to check your source coil resistance which should be 1.65ohms +/-10%). When you get to setting up your timing 3.2mm BTDC this resistance measurement is handy to know because your multimeter will change from 0 ohms (i.e. points CLOSED) to give you your coil resistance value (i.e. points just OPENED) . Hope this all helps, Andy L

I'm thinking--if the earth end of the coil is obvious--& will be coming out of the inside-- then just solder a screw terminal to it & earth it to the coil mount screw. Then run the other end coming off the outer end of the windings over to the condenser. This in the end should find its way up to the coil under the tank once joined with the condense & points. Usually is a black starting from the condenser then heading into the main loom from the mag loom. Can short cut it direct if you want & take the mag loom black straight to the plug coil. If you go direct just be damn sure the throttle is nice & free operating & most importantly shutting right down as sure don't want it taking of minus the rider.

Sorry AndyL above, i hadn't read yours first & just got straight into it from my email telling me something was going on lol. Hope i've not confused the OP with my woffling & messed with your good info, Cheers,

Glad to see that your wiring issue is getting some attention. It would be great to see some pix of the bike and that great New England scenery. The back story on your bike from the intro forum was interesting. Sounds like you found a previous owner with some great adventures.

Ok, sorry for the delay I have project ADHD and have been giving my 63 Honda Dream 305 some attention. Andy I attached a photo for your inspection, my first time soldering not pretty but I think it will work. Resitance on the coil was 1.6. Thanks for your help Andy!

As soon as shes running theyll be pictures galor for you. One of my good friends has more of a vintage addiction than me I think his current count is 4 bikes and 9 mopeds ranging from 1959 to 1979. But we plan on doing a couple rides up in NH and VT Im envisioning a lot of photos of her under covered bridges and fall foilage.

Yep CaptCove technically you have everything correct with regards to my wiring advice so well done. Practically I have a couple of concerns because from your last picture the red wire running from the condenser to the points looks as though it will be 'rubbed' bare when the flywheel is installed and rotating with the shaft, so you need to route the wire away from the centre and more towards the lighting coil winding. The outer black wire from the source coil to the condenser looks to have a very flimsy solder connection to the blob and possibly is routed too far out, which means it could be rubbed by the flywheel magnets. Similarly the green wire you've used to earth the source coil looks as though it has 'kicked' clockwise as you've tightened down the source coil retaining screw. Maybe it's all o.k. and just appears like that, only you know if it's good to go. Look at the curvatures on the four 'shoulders' of the coil formers and ask yourself 'if they were all part of a circle, would all my wiring be tucked safely INSIDE the circles circumference' because that's the path the magnets take with very little clearance (flux gap). Lastly where is the fixing for the small oiled felt pad that should rub on the inner face of the flywheel shaft? You need this to ensure the face that interacts with the points rocker arm is clean and very slightly lubricated. Overall though it looks like you are getting there. All the best Andy L.