40hp 4 stroke bottom end question?

[Cold Atlantic]

I can't figure out why they this motor will not go into forward. I have had it apart three times but nothing Is jumping out at me. So I want to replace the bottom gearbox.
My question is what other bottom end model/s fit this 2010 40hp 4 stroke?

 

[Cold Atlantic]

I found a lower unit for 200 bucks but the hearing is different. Mine is a 2.00 to 1 this one I found is a 1.83 to 1. Will this make a huge difference? I really don't care for top end speed so i assume it would just hole shot better and plane faster right?

 

[Cold Atlantic]

Nothing huh?

 

[Mercurylips]

What happened that it is not going into forward? Did you just replace the water pump impeller? Pretty newish motor to need a lower end already.

 

[Silvertip]

There is a reason the 4-strokes use 2.00:1 vs the 1.83:1 on the two strokes. The four strokes don't get out of the hole as quickly as a two stroke. Therefore they compensate for that by the gear ratio change. That is also the reason the two stroke gear case will allow faster boat speeds at slower rpm than the 2.00:1 assuming prop pitches are the same in all cases.