Kanyon Pershing

I have recently rebuilt my Yamaha warrior 350 engine and when I got it all back together with no “spare parts” i went to start it and realized it’s in reverse. I went to put it in drive and the shifter won’t budge, I took the linkage off and tried to use vise grips but it won’t budge at all. Any help would be greatly appreciated. I’m hoping it’s not something internal!