Just googling HT1 & this came up. Hope link works.
ridermagazine.com/2018/01/29/the-seminal-motorcycle/

MarkT you are correct the HT1 didn’t have blinkers in the USA on mine I made the wire loom for the blinkers on my bike I worked at Butler’s Yamaha back then and have a movie of me riding it on the first day I got it and it didn’t have blinkers was so happy to get it

I bought my new 1970 DT1C off the showroom floor in December of 1970. The new 1971 models were also in the showroom with turn signals. As I recall I saved $50.00 buying the 1970 model and I liked the RED a whole lot better then the Orange.

"Turn signals were not and are not required for street use in the USA if bike was manufactured before 1-1-1973."
So you are saying that even though turn signals were OEM from 1971 on they are not required on my 71?

When I lived in Texas you didn't have to have turn signals on your bike, at least classics/vintage so not sure about "modern" bike but if they were they then they had to work. In Texas you have to do a yearly safety inspection.

In Tennessee we could get a motorcycle license at 14 yrs old had to be under 5hp and have crash bars at Butler’s we would put a throttle stop and have a letter from Butler’s that it’s under 5hp and we made up some crash bars to use to get our license then we would take it off and reuse it for the next customer Cops never checked us and no turn signals. Man those were the FUN days 

I rode to high school on my 72 175 Enduro, no license, cops left us alone but then I grew up in a small farming town.

Cheers for the reply’s guys, I’m still working the site out so am missing replies,
I’ve had the bike dated via the vin/engine numbers as looking at registering it over here in the uk.

"So you are saying that even though turn signals were OEM from 1971 on they are not required on my 71?"

Short answer:  Check your state law.

Federal law did not require turn signals on motorcycles until 1973.  Most states follow Federal law, but there could be exceptions. 

The ORIGINAL Nevada law on motorcycle turn signals hit the books in 1971 and said any motorcycle manufactured after 1-1-72 had to have turn signals.  That law was repealed and replaced to be consistent with Federal law that said 1-1-73.

Every state I've checked has their current motorcycle turn signal law consistent with Federal law...  that doesn't mean all do...  and it's likely Yamaha started putting turn signals on bikes in the 1971 model year because some states started requiring them?

The "motorcycle sold in USA must be manufactured so headlight must always be on with engine running" law was something the Feds came up with in about 1978...  but every state I've checked still follows the "common sense" headlight on rules which are usually headlight on half hour before sunset and half hour after sunrise...  or if visibility conditions warrant the use of a headlight.  So you probably don't need to ride around on the street during the day with your headlight on if you want to be a rebel and have an older bike that has a headlight on-off switch.  Again, check state law. 

One thing about all state light laws is generally "if you have them, they need to work".  So you can't have turn signals installed on a 1968 bike and try to say it's ok if they don't work because you don't need to have them...  or ride around with a burned out headlight because it's daytime... if you have them, they have to work. 

My HT1B has US lighting and headlight lens and came with indicators. As you stated Mark, my bike is a 71and has the round rear light and reflectors.
It also ended up in Canada . I'm sure i read some place on another post that Yamaha offered them as an optional extra on all their bikes of that era.

Shyted, I have the stay for the left side as you sit on the bike, so only need the right hand side, deffo interested in in the bits of switchgear and the sleaving

Kev