I’d forgotten how tricky 2 strokes are to tune.

But so nice when it's right. Finally got the CR80 running great with the new PWK carb...at 65-75 degrees & 70%-80% humidity anyway.  Did hours of needle research on getting the MX hit smoothed out & found some Sudco straight taper needles that don't have steps & therefore no big 9,000-10,000 rpm hit where you flip over backwards since the wheelbase is short & more weight on the back. Came close a few times when tuning with the stock needle.  Got the jetting really good with a bit of slightly rich at 1/4-1/2 throttle then it smooths out & away you go. 3rd gear now on pavement the front wheel will gradually come up but is very controllable. The reed cage spacer & the pipe spacer help also to lower the hit rpm.  Also got the kickstand adapted & installed the lights. Waiting for the Li-ion battery to arrive. All the electrics will be behind the front #plate. 

I picked up two thrashed 1989 YZ80's a few years ago and did a ground up rebuild on them for two of my kids. I painted one frame white and one blue to tell them apart. We promptly seized one because it was running lean and I didn't notice, so I quickly ordered a new piston and a crank and rod kit from Ebay. But the crank and rod turned out to be from a later YZ85 and had a longer stroke. I built an aluminum spacer to go under the jug, drilled out the new piston to take the thicker wrist pin, and changed the timing a little. What an absolute rocket. It had all the short wheelbase put you over on your ass snap of an 80, but the extra 15 ish cc's and longer stroke gave it quite a bit more torque and I could trail ride it. All 200 pounds of me. I thought with a longer swingarm it would have been fun to do a hare scramble on, and I could have just picked it up and carried it over obstacles. 

That's what I'm doing to this one-lengthening the swingarm by @1" to run a 16" tire in the back. I also have a spare cylinder & head that I'll be sending to Eric Gore for higher compression & 100cc. It's a lot fun to ride & fast enough for me. 
I made sure it wasn't too lean. I kept stepping up the the main jet until it was blubbery at wot then went back 1 step. 
The forums I read are really close at this sea level.