Vintage Dirt Bike Q & A

I have a 81 CR250 I've working on for a while, finaly got it running but it runs very rich at low to mid range(almost unrideable)carb is very clean main and pilot jets are correct from the info that can be found.at this point I'm wondering about the needle jet(the needle) is has a 28H on it but cannot cross that number over to see if its correct and a new one is not available. Reeds look good,piston & rings looks fresh,just put in new crank seals,air filter is clean,bike looks likes its been running rich for a long time before I got it. So any ideas or info would sure help, Thanks