1970 CT90K2 , yellow , unrestored but in pretty good shape @ 5,200 + miles , I took it out to Borrego Springs , this is in the Eastern Anza Borrego Desert , & rode the crap  out of it at the annual Antique Motocycle Club Of America's gathering , they have decided to allow vintage Japanese Motos in and everyone was quite friendly and most said they'd had or had ridden a CT when they were young .

I rode it hard , far & wide for two days .

Friday we took a Road Trip up the Mountain to Julian for lunch , interestingly , all the $40,000 restored Indians and Harleys slowed way down in any corner so as soon as the twisty bits began , I was able to catch up to and pass , all of them banana dance .

Naturally , as soon as there was a straight bit , they all came zooming past me like a rabbit in a thicket , tooting their horns & giving me thumbs up .

On one flat bit , I was clocked @ slightly over 50 MPH ~ a big surprise to me as I now weigh 238 # and the CT90 only has 7 HP IIRC , at the time I had (as usual) the throttle pinned and it was buzzing merrily along rock on .

Once I got there I tanked up on fuel and headed back down because it was only 45° F & 35 MPH winds there and I only had my leather jacket & gloves so I was freezing my butt off Sick .

A couple guys I know  saw me going past downhill and later said they'd never seen a CT90 go that fast , I was surprised as I didn't pin the throttle on the downhill parts as I don't believe that's good for it .

BTW : ANY Diesel rated multi - vis oil is what's best for any non catalytic converter equipped vehicle's engine .

I highly recommend using synthetic oils at all times as they stop the wear cycle dead wherever it is , do expect some more than usual seepage (not leaks !) from synthetic oils .