Bike in question is a 1975 DT100. Problem is ignition switch is missing. NO KEY... Gas cap requires a key. Is there a key number on the gas cap??? I DO NOT have the bike in front of me...

I think I may have found my answer on FLEABAY. Shows gas cap with key number. Am I correct???????

You can always take it to a locksmith, they can make a key for it. 

Hey Tony, ya but I'd like to see inside the tank before I even think about buying it

Ya I went on fleabay and saw a gas tank for same model. It had a number on gas cap lid. Not sure if that is 100% correct or not

 I have the same bike, yes it has the key code on it as does the ignition and the seat/helmet latch, unless your gas cap or seat latch have been changed out the keys should match the lock on the gas cap and helmet/seat latch as well as the ignition and steering lock. Also another note I have been in your situation, it is usually the gas cap is just rusted to the tank, I’ve used large channel lock pliers with a rag around the cap and they usually come loose, very rarely did anybody actually lock the gas cap, I’ve had over a dozen DT250’s and DT400’s and I have never actually used the lock on the gas cap.

 

 

Thank you
 

Hi John, sorry I was thinking you actually had the tank.  Yeah seeing inside would be very important, I've seen some pretty rusty tanks on ebay but the outside looked great.

OK I bought the 1975 DT100. NO ignition switch like I stated earlier. Gas cap was not even locked just on tight. So back to the missing ignition. I'd like to try to get spark at least after I get the piston unstuck..

My question is " how do I hotwire it" for a lack of better words?
  
 

What is the white plug that is just out there for???

Hi John, glad you got the bike!  There was a time, decades ago, when I knew how to "hot wire" a Yamaha 2 stroke but just can't remember how...  I'm sure someone will know.