Trim Lowering Problem

Hello I have a 1984 Procraft 1650V with an Evinrude 115 4cy. My problem is that the trim will not lower down. It raises fine and when I press down I can hear the motor and things turning but I have to manually lower the unit. Any idea what is wrong and is this something i can fix or do i need to take it in?

1983 Evinrude 115hp
E115TLCTE

Thanks,
Leon

I would suggest you take it in.

I got a hold of the guy who I bought the boat from today and he told me that the problem is a Check Valve. This this sound correct to you all? A check valve keeping the unit from trimming down?
Thanks

That would be correct but there are several check valves in the trim system.

Roger that! I will find someone to take a look at it, Thank you