This blasted ES system!
Hoping someone can give me some ideas as to what to look at. I'm no stranger to the single week link in the Honda off road empire. The bloody electronic shift system. My 250 has it, my 420 has it and i have heartburn.
My 420 lately has been randomly refusing to down shift. It can happen after an hour of using it, or 10 seconds pulling it out of the garage. Sometimes it doesnt happen at all. There seems to be no repeatable series of actions that will repro the issue.
Things i've done:
1) replaced the shift motor
2) replaced the tilt/angle sensor
3) pulled the shift motor checking the teeth, re-gasket and reinstalled
4) checked battery health to make sure it has enough power to shift.
Everything checks out, i did some research to find that the motor oil is also what lubricates the gear box, so adding lub is out (from what i can tell please tell me if im wrong).
What other sub-system should I check.