My 1982 1050 (sn 8206)is a Yanmar tractor painted in John Deere green. I'm having problems with my PTO. While mowing the other day the PTO kicked out now it won't fully engage. I have just now adjusted the PTO clutch and it's working properly.The PTO lever is supposed to have 2 detents but it travels aft (disengage) farther than the "disengage" detent. The detent in the "engaged" position does not engage the PTO however, if I push past the detent, it will engage but not fully and will pop out at the first bump. Any ideas on what the malfunction is?