Picked up a 71 CT! 175 last night. I drove three hours to pick it up and didn't get a bad deal on it. It definitely needs some work but the paint looks great so that's a plus. The carb needs a good clean, breaks are stuck, needs some wiring, and is fairly dirty but it isn't stuck and still has compression so that is a plus. It has 8000 miles on it and everything import is there which is nice, Cant wait to get it running again after I get the rust out of the tank haha. I would love to add photos but for some reason, I am unable to today.

Look forward to the pics when able to do so. Love CT1's. Bring back piston port models i say.

Here it is! Also picked up a 1980 Suzuki sp400 in the deal.

Your CT1C looks good. I am going thru the same bike right now. Mine was also very complete and I decided not to restore or refurbish this one. Instead I am just tearing it down for complete cleaning. I have ordered all new seals, brakes, air filter, and a few misc parts. Hope to be done by spring.
 

Wow, great looking bike there!! Trying to get mine to look that good by spring!

I tested spark and it appears to have good spark which is good news even with the ignition switch disconnected which confused me.. The coil has two mounting holes but only one place to mount but Ill figure that out. I need to get a new spark plug wire and boot as that connection is sketchy at best. I'm going to clean the carb and de rust the tank and see if it goes here in the next week. It is looking good and I am going to order cables, brakes, levers, air filter, petcock, grips and really get it cleaned up!

If the ignition switch is unplugged, the bike will start up. The reason I know this is my 1971 CT-1 was stolen that way back in about 1973. It's an odd quirk in the wiring.

By the way I'm in the process of fixing one up as well, it's been sitting unridden for over 20 years. I got a ton of rust off the rims, cleaned out the carburetor, and for a week I've been trying to clean black goop out of the tank. It has a real hard layer that's solidified in the tank.

I also just got a new battery, and changed out the gearbox oil with Yamalube 20/50.

If you have E85 near you, fill tank with that.  It will dissolve the gunk.  Or get Ethanol from hardware store.  Just let it sit a few days.

I appreciate the reply. I've been trying to do this so I don't create a big hazardous mess I have to dispose of, so have been trying to avoid filling it with gas that will have to be disposed of when it's contaminated. I had been using vinegar, but today I changed tactics... I emptied the vinegar out and sprayed some Onan 4C carburetor cleaner in there, with all kinds of nuts and bolts and drywall screws. It seems to be dissolving everything right now, so I'm going to let it sit overnight and see how it is tomorrow. Then I'll just have a small amount of hazardous material to dispose of.

By the way, I just hooked up the new battery, after it was charging during the day, and I can't believe it... all of the lights and the horn work! Of course the headlight doesn't come on because I can't start the engine yet. The turn signals come on and don't blink, but I'm thinking maybe that will work when the engine is running. If not I may open up the flasher relay and see if I can clean it up. 

I wouldn't call running with the ignition unplugged a quirk in the wiring. It's a pretty common design choice so that the engine runs if something goes wrong in the wiring. Cons = easy to steal, but if you loose your key or a wire rubs through thirty miles out in the middle of nowhere, you can at least get home.

I'd did similar with a tank and still needed to run an inline fuel filter after the cleaning. It still picked up a surprising amount of junk over the next year, enough to plug the filter. They are cheap and easy to install, plus give you a nice visual indicator of gas flow so why not, unless you really want the 100% original look.