Hi -

I have a 1975 DT250B "survivor" that has the following symptoms:

1. Bike will start and run regardless of the ignition switch position - no key needed to start.
2. Kill switch will not shut down the bike.
3. Headlight and turn signals have worked in the past, but not robustly.
4. New, charged battery installed.
5. New bulbs installed.

Ideas on how to correct - would like the ignition switch to function - is that a ground problem that is also tied to the lights not working? ...or do I have a bad switch?  An ideas or knowledge appreciated.

Thanks!

++UPDATE: Shutoff by the key now possible - thanks! Now on to the kill switch and lighting...

Greetings from Tennessee 
 Is the ignition switch plugged in to the harness and have you checked out all of the connections and ground 

Hello
A multimeter to check for continuity is the cats meow , i never really knew how to use one until I visited this Great forum , you could check out my posting kill and key switches won't shut engine off, or something like . 
john
 

Key switch and kill switch not working is the name of my posting type that in the search box

I would start with the key switch itself.

The black and black/white should connect with key "off" and disconnect with key "on".  Those are the wires for the ignition.  No battery power to either.  Black goes to ground and black/white goes to ignition coil.

The red and brown are opposite.  Red is disconnected from brown with key "off".  Red connects to brown with key "on".  Battery connects to red (through a fuse)  Brown powers all the battery-powered items...  taillight, turn signals, horn, brakelight...  i think that's it on that model.  headlight and gauge illumination is AC powered and only work when engine is running.

Many times here people post up with the same/similar issues...  here's the other thread.  There is good info there...  warning though...  some of it makes my head spin, even the stuff I wrote!

yamaha-enduros.com/index.php/forums/74-7...l-switch-not-working

MarkT you were on a mission to get it figured out jewel kutter you did a good job following MarkT instructions Great job to both of you  Now my head isn’t spinning anymore 

Hi DCWILSON, if you haven't already you could check all the connections for oxidation maybe get some deoxit or sand em clean then plug em back in if the fit a little loose you could gingerly squeeze the females a hair so the males will fit tighter or clip em an replace them with new you can get decent wiring connector kit on the web check the nuts and grounds on the rear blinker stems look for cracked or frayed wires at every connection .
There's excellent people here on the forum , very knowledgeable when it comes to our old bikes and willing to go the extra miles to help . I'm glad I came here.
It took 13 pages I'm still a little dizzy , but it was worth the time. so glad MarkT was patient with my mix ups , Great teacher ! wicked great teacher . .now I understand how the meter works for testing continuity and
how the switches function . it's a good tool to have . Wish I would have know a long time ago.
the signal light on the tach is another blinks off the battery on my 74. it all can be tested for continuity each individual circuit GR8UNCLEAL mentioned that on page 1. when I was just starting to learn it . I love this place .
John