Compression release mechanism may be the small gear in the pic. According to manual all HH120 had a CRMI'm not sure what may be hanging it up, Jazz? If that is a HH120, the crank cover came off pretty easily on my 1975 MF12G while still in the frame. Had to re-power the tractor though. The only mechanism I saw in there was the governor. I do remember from 20+ years ago, go kart racing, some engines had a compression release ground in the cam lobes. This engine may have been that way too?
DAC
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Jazz, looking at your picture and MFDAC's picture it looks like the one bolt on the top just right of the crankshaft needs to come out. The one with the metal piece on it with a hole in the end. I counted 9 bolts that hold the cover on, the 2 guide pins will make it a difficult to move for the 1st 1" or so coming off.This is engine from my Avatar
I’m convinced compression release mechanism is not functioning. Trying to remove this crankshaft cover. Does not seem to want to leave the mother ship. Any suggestions, all bolts removed. Am I missing something? TIAView attachment 32883
Correct. Cover came off easily. Seems the CRM is working. The spring is intact so valves must need adjusted. The engine is hard starting and it’s not the starter.Jazz, looking at your picture and MFDAC's picture it looks like the one bolt on the top just right of the crankshaft needs to come out. The one with the metal piece on it with a hole in the end. I counted 9 bolts that hold the cover on, the 2 guide pins will make it a difficult to move for the 1st 1" or so coming off.
Hmmm. Is that notched gear on crank gear a timing mark? Just noticed it. Intake is 010, exhaust is 020, should be 020 View attachment 32929