trim problem

[GKT]

i have a 1980 mercury 200 with one trim cylinder on the transom and the pump in the boat. i have a deep vee hull center console 20 footer. the trim works totally fine on the trailor and when im stopped on the lake. but it wont trim up when im at cruisin speed. i have to keep the motor down the whole time. i can hear the motor trying but it just wont go up. do i need to rebuild the system or what?

 

[Barnacle_Bill]

Re: trim problem

Check the fluid level in the pump.

 

[GKT]

Re: trim problem

the cylinder goes all the way up so i dont think its low. and also the check plug is frozen, so i couldnt check it if i wanted to

 

[Mac uk]

Re: trim problem

Is this any use. Could have air in the sytsem.