Installed new B1 complete unit from merc and when i put it in reverse it takes awhile for it to engage,when it's cold. As it warms up it goes right in. Any ideas? I have been playing with the cable adjustment,no real change.

External problem
1) Cable adjustment

Problems in the drive upper
2) linkage pivot or arm needs replaced
3) cone clutches have separated from the gearsets
4) cracked floor of the gearset.

You can drain the lube, and then pull the rear inspection cover off of the upper.
Remove the prop, and remove the belt to the seawater pump and you can briefly run the motor and observe the shifting. Dont try to shift with the input shaft not spinning. You should be able to see what's up

MC

Being a new drive, setup could be an issue. Being new, it should be setup correctly???
I would look at the depth adjustment on the transition block. See if it has moved. The barrel adjustment will center the linkage to the detent ball in the back cap. The slot adjustment changes the amount of rotation of the shift fork cam. Not deep enough and it not fully engage. Too deep and the cam will rub on the bump rings. There is a set distance for the slot adjustment, I just dont remember the number at this time.
Have you tried shifting it manually?? Take the cable barrel out of it's holder and shift it using the cable. If it goes in good, when cold, it is a cable adjustment. Probably needs a little more on the depth (as I call it).
Hope that helps.
Dick

Thanks for the input,i'll check out items listed. I don't see how some of these things make a difference hot or cold.