Mercruser Alpha 1 engine stalls will not attempt to go into gear

"Hi Everyone
I just signed u

"Hi Everyone
I just signed up, a lot of good info here.
I have a 1986 Imperial / Mercruser / alpha 1
I just took down the bottom of the lower unit
to inspect the impeller.
[engine running a little hot]
My problem is after I put everything back together, the engine starts and run's fine
throttles up ok. When I try to engage the prop
the engine stalls. I don't get the normal little grinding noise when the prop attemps to engage. The engine dose not attempt to throttle up it just stalls
I must have put something together wrong.
I don't think I had the throttle control in the forward position when I droped the lower unit.
I have read sence, that it is supposed to be in forward position before you dropped the lower unit. Could that be my problem, if so how can
I Fix It?
Any info would be very much appreciated.
Thank's
Bill"

"take it back off, put in fwd.

"take it back off, put in fwd. re install. probably have shifter splines wrong. shift interupt is killing engine. another reason not to remove only the lower with drive on boat. be happy that you saved $6 on gasket. then do it over. you may want to consider doing it right this time."

Thank's for the info.

Thank's for the info.
I'll try to do it right next time !
Bill