Hey all.
Am hoping someone can help please.
I have a 2000 Honda foreman 450 foot shift,
Sometimes when I try to shift from first to second, it goes back into first.
Sometimes when I shift, it will click click click, then go into gear..Every Time I shut the machine off, something in the engine winds down and then clicks and stops.
Things I have done is I replaced both clutches and one way bearing.
I have the engine completely apart with the transmission exposed and I can see nothing wrong, no wear to an untrained eye.
Any help would be greatly appreciated.

 

You have two separate faults. The gearbox could be anything on the selector mechanism. The sprung wheel that rides in the star wheel is quite strong so, once over the tip of the star it takes quite a force to make it drop back. The pawl that moves the star wheel round can crack or a bit break off and the lever that moves the pawl can crack too. I've just had a 450es with a loose star wheel but you would have noticed this during the strip down. I've also just rebuilt a 500 gearbox and slight wear on the ends of the dogs that engage when changing gear makes them jump out of one gear into another, bent selector forks can also be a problem, as can worn grooves on the drum where the forks run.

The only thing I can think of that can continue to spin after you shut off is the starter motor, your one way starter clutch could be sticking, it may cure itself. The one way clutch you replaced could also wind the mainshaft up in neutral, if dragging, but couldn't do it if you switched off while still in gear.

 

Just re-read your post, and the gearchange problem could also be the multiplate clutch. Are you sure you adjusted it correctly after fitting the new one?