Does anyone have this shifter problem

I have a 73 850 and it starts and runs great, but I do have one little bugabo. It goes like this: at least once each outing when I am in fourth gear and preparing to stop and start to shift down, it will not get out of fourth. If it is reasonably flat, no big deal, I just reach down and down shift with my hand. It takes a little rocking to get it out of fourth, but from third on it is easy. All this is a little inconvenient on a steep hill in traffic so I would like to fix it. Tranny is otherwise in great shape and I use Redline MTL. Shifts like butter all the rest of the time. Any thoughts would be appreciated. Jim

Are you coming to a stop while still in 4th, and then downshifting while stopped. ??
Do you have this same problem while in 4th, and shifting back to 3rd for say a tighter corner, or to overtake something ?

If stopping, most riders would be downshifting while still moving, so you end up in 1st while coming to a standstill, and then just click it into neutral.
You'd get a fail in riding school if you aren't doing this....

If your clutch isn't well adjusted, or your primary chain is too tight can cause some odd shifting problems.
Old or tired springs in the shifting mechanism could be involved here too, maybe.

Rohan said:

Are you coming to a stop while still in 4th, and then downshifting while stopped. ??
Do you have this same problem while in 4th, and shifting back to 3rd for say a tighter corner, or to overtake something ?

If stopping, most riders would be downshifting while still moving, so you end up in 1st while coming to a standstill, and then just click it into neutral.
You'd get a fail in riding school if you aren't doing this....

If your clutch isn't well adjusted, or your primary chain is too tight can cause some odd shifting problems.
Old or tired springs in the shifting mechanism could be involved here too, maybe.

Click to expand...

Remember it's only one time a ride. Yes, I try to shift down while moving but on that one time, my foot cannot make it shift. That's why I end up doing it when stopped. All the rest of the time, it shifts beautifully up or down. It's like it gets hung up on something for that one time a ride occasion. Jim

When its that one time, have you then tried shifting it UP a gear - just in case 4th isn't properly engaged somehow.

Clutching at straws here...

If it keeps doing it, you are going to have to open it and have a look.
After checking chain tension, clutch adjustment, etc.
Probably with a spare spring in hand for the change mechanism...
And have a look at the pointy index plunger thingy, in case its not so pointy any more.

Rohan said:

When its that one time, have you then tried shifting it UP a gear - just in case 4th isn't properly engaged somehow.

Clutching at straws here...

If it keeps doing it, you are going to have to open it and have a look.
After checking chain tension, clutch adjustment, etc.
Probably with a spare spring in hand for the change mechanism...
And have a look at the pointy index plunger thingy, in case its not so pointy any more.

Click to expand...

My first reaction is to first make sure it is fully in fourth. So I do do that, but thanks for the very good pointers and I will check for these. Jim

Try loosening the primary chain a little to see if it helps.

Remove the outer cover, check that the little spring allows the shift pawl to wiggle slightly, if not bend both legs a bit to have around 0,2mm play each side of the pawl. The pawl needs to move freely, some problems are coming from everything rusted up inside the outer cover. Check that the small spring is fitted the right way round - both legs parallel to the quadrant.

I'd fit a brand new shifter spring . New quadrant positioning spring too. Original ones are 45 years old and weakening a tad.