Erratic Trans Problem. Shifts up OK but will not downshift every time, is erratic on and off. Trans lube full and clean, linkage & clutch OK seems.
Some examples; run several miles in 5th, gear down to 4th OK but then won’t drop down any further, lever feels like it’s already in 1st. Get stopped at light, shift lever back and forth then it may or may not drop any further than about 3rd, sometimes 2nd then no more. I've released clutch on and off and play with until at least getting it into 2nd. Have had start off in second then again shifts up just find. I have also noticed that after slow starting in 2nd I've then been able to then to drop it down to 1st.
Other times noticed I can run light to light, say lower gears then seems to downshift OK as if no problem at all.
It's crazy. And advice on which way to go on repairs needed is appreaciated and thanks in advance.
Etuck

 

Check the shift linkage again to make sure it moves freely. Make sure the shift lever at the transmission is tight on the shaft.

Does the shift lever spring back to its centered position?

 

Yea linkage is OK and shift lever springs back.

 

With the engine not running, try shifting from first to fifth and back down (you will have to roll the bike back an forth a bit so that trans will shift), does it shift ok?

If it shifts ok when the engine is not running, it is probably a clutch issue, remove the primary cover, and disassemble the clutch plates and disks (you will need a special tool to compress the clutch spring for disassembly), inspect for warping and damage, especially the spring disc in the middle of the clutch pack, they are notorious for failing.

Another cause could be the shift pawl is out of adjustment, you will need to remove the top cover from the transmission. The adjustment is very simple, the worst part of the job is removing the oil tank.

 

Found out today that the back spring in the transmission on the shifter is broken. I guess all the gears in the tran case will need to come out to replace he three dollar part. Not sure how long the project will take to get her fixed, but I'm thinking a good half day or better.