I am pulling my hair out. I have had this rancher ES for over 20 years and had it act up a little in shifting but never lasted long. It is now persistent so I put the bypass on it and not much has changed. Sometimes no response when I hit the up or down button and other time when it does shift it changes the gear but there is a noticeable pause before the transmission responds. I checked the shift motor and it has 9 ohms. I bought another one on amazon and it has 9 ohms also but it would not change the gears at all. It only shifted up once but never let the transmission engage fully. Tested the battery and getting 13v when running.I am wondering if the area where the reduction gears are just need to be cleaned and fresh grease. I have ordered another one on amazon (different brand) to see if there is any change. I am just wondering why it has the lag when shifting.
*I did see another video that said it should read 12-15 ohms...not sure if that is true

 

The first thing to check is if it changes OK manually. remove shift motor and gears and it is now a manual change bike, if the gears can be selected ok with emergency lever (engine running) the problem is electrical. If it doesn't, you have a selector mechanism problem. 350s were prone to cracked and broken levers inside the clutch case, star wheels coming loose and I have had two where the rod that the selector forks run on has broken through the casting, into the clutch case. All these can be seen with the clutch cover off.

Electrical faults, if you have by-passed the computer, it will be the buttons themselves or the wiring. Take the old shift motor apart and see if there is something wrong, almost always worn out brushes, or magnets dropped off, seizing the motor. Do grease the shift motor gearbox. I had an old 500 ES last week, wouldn't change back down into neutral from 1st or reverse unless you stopped the engine, shift gearbox very dry and clutch well out of adjustment, fixed them and smooth changing was restored.

 

I would remove shift motor and the gears and re lube I put gear oil and grease in wd40 lid [just small amount] and mix together to make a paste the gear oil in the mix keeps the paste from drying out through the years I would do that first then do what merryman said above.

 

Once you have the gears out, do the test with the emergency lever. When you have it back together it is harder to tell if there is a mechanical fault, as the emergency lever has to turn ES gears and motor as well as change gear.

 

I took the the shift motor gear box off and cleaned all the gears and put fresh grease. I also put a new battery in just to be safe. The old one was dragging a little. Should get a bunch of snow here in Kansas City tomorrow so I will be using it a lot and see if it continues.

 

Could the delay in shifting from when I hear the shift motor move the gear to the time the clutch kick in be from it needing a clutch adjustment and is that something I can do myself. I see the adjustment nut on the outer case.

 

Slacken locknut, turn screw clockwise a turn, then anti-clockwise until "resistance is felt" then clockwise 1/4 turn, re-tighten locknut, keep checking the nut hasn't tightened on the screw when adjusting, as you can think you have got to the "resistance" point, when it is the locknut.