Hey guys i have a 1978 Dt175. I started her up made it a 1/4 mile down the road and then got a ton of electrical burning smoke from the bike. I shut it off for a few minutes and inspected. I can’t find the wire that burned. My neutral and oil injection light are wildly dim now though. That’s the only symptom. Gauge lights and headlight works. Any idea where my problem is?

Check the rectifier under the fuel tank.  Has a red wire and a white wire going to it. 

Okay I’ll look tomorrow. For what it’s worth, I was a half mile from the house. I started the bike back up and rode home, no issue other than the dim indicators lights.
It had actually been a while since I started it and the battery was nearly dead. I’m surprised it started and ran without issue after that smoke show

I still have a feeling it's the rectifier.

Charge the battery if you can before you install a new one.

My first thought would be rectifier too.
But on re-thinking, if the rectifier was out of it [shot], would that then let the light glow bright at revs unregulated [as in unrectified]. I don't know, just asking--just saying!!. Food for thought or food for the scrap bin lol.

When rectifier burns up, most of the time the battery charge circuit is effectively disconnected.  No power goes into battery from magneto charge coils. 

A couple of times I've seen a rectifier "half burned" by someone accidentally connecting battery backwards for a split second...  then the battery will try to discharge through the stator with engine off... with engine running, battery will be fed with AC power which will quickly destroy it.  But that's probably not what happened here. 

This sounds like rectifier (diode) was handling a lot of current (most likely due to low battery allowing a lot of current to flow) and diode gave up.  Old diodes sometimes just short out.  I've seen that happen quite a few times. 

Earlier bikes had those bulky "square plate" selenium diodes (rectifiers) that were replaced in the early to mid-70's with the small "modern" electronics type.  It's hard to remember that the first of the Enduros were built when you could still buy a new TV or radio with vacuum tubes instead of transistors.

You beautiful man! Anyone care to spoon feed me a part number or good link to the correct one?

ibb.co/kqhCx4D
ibb.co/Tm0ZS3z
ibb.co/RvFdXbt

Yamaha still sells them.  Used on a lot of models so probably some aftermarket on ebay cheaper.

www.partzilla.com/product/yamaha/1M1-81970-60-00

Mark, Do you have cash app or Venmo?. I’d like to buy you a 12 pack

Greetings from Tennessee