Just brought home a 74 with 500 miles on it. It's been in a barn for 30 years or so.I will be here asking all kinds of questions no doubt.
I can't get the pic to attach though.

74 what?

Hopefully it’s a motorcycle, possibly a Yamaha and preferably a two stroke

Welcome from NZ. Be a Dt250a or 360a is my guess. Pics are a problem but need to be linked through an external thingy. I'm not the expert but use Google photos to link here. Most others seem to use "Imgur". Look forward to viewing them sometime soon. Cheers. Ps, I feel your excitement though. 500 miles,  great they're still out there to find. No chance of that where I live, they've all been well worn out. Are you in the USA?. I did ride a dt360a to work about 30 years ago, was good too. Was a rough one in the shed out the back at work. Was well seized. Probably no oil in the autolube tank. But new piston kit & a clean up then used it for a long time.

that may be helpful.
it's a 125 enduro
tried linking pics via imgur with no luck. 
I'm in the frozen tundra above you folks.

Hope to hear more about your bike and where you are from.