(ET) Speed / power drain / reverse problems C185

[Biophiliac <keljefs sbcglobal net>]

Hi all,
I believe I posted this question previously but still have yet to solve 
and actually use my C185 because of it.

The problem (s):
1)Reverse only works in fast cruise mode (cruise never has worked also) 
and only by putting foot to floor. It jerks hard when engages / 
disengages, especially with D1and D2.

2)When moving forward especially noteable in D1 and D2 the power draw is 
HEAVY and the front resistance coil gets hot and burned smell. I have 
never used the tractor since I've acquired it other than test driving 
short distances,  and I doubt the speed has reached more than 5-7 MPH. 

I have tried new contractors as per Harold and has not made any difference 
. (I appreciate your help Harold nonetheless ; and understand it was an 
educated guess) 

 Jim C suggested it may be diode issues in the varistor board...but I am 
currently unemployed and can't afford to keep on guessing what's wrong. 
Could someone please help?  

Jef Spalding