1980s morbark eager beaver 200 chipper misfire problems

[Wood1987]

I got a 1980s morbark eager beaver it's the 200 model and it has the Ford 2.3 l 4 cylinder in it and once it gets warmed up it wants to misfire when it's running at top speed with no load once you start running wood it clears out and then I'll go back to misfiring real bad and I've changed all the electrical components and put a new carburetor on it does anybody have a wiring diagram on this or have any ideas what it could be I rewired it with the Ford dura Spark ignition wiring diagram thanks please help