Need help with jack screw power trim on a 305 omc/omc 800 I/O

[fabrimacator21]

Hard to explain but my trim won't move anymore, it just clicks (soleniod). I need to trim it down in order to change the belt I fried but I can't get it to budge. Tried prying on it to help it out but no cigar. Anyone have experience with this type of power trim? Basically I want to get the motor seperated from the jack screw but I can't because I have to use the trim in order to unscrew it from the bracket. Tried manually unscrewing it but it only goes so far then won't move. HELP!

 

[Howard Sterndrive]

Re: Need help with jack screw power trim on a 305 omc/omc 800 I/O

check voltage drops from battery to trim motor to find high resistance part of circuit.
OMC specs are 1 volt drop max allowed at any connection, at least 9.5V drop across the motor itself.
otherwise, removing all the heavy current side terminals at the relays and filing them all shiny on both sides usually helps if not doing voltage drop tests.
check the two 50A barrel fuses that feed all of your electrical in the engine compartment for corrosion.
There is usually a grease fitting on the worm gear part of the trim unit. could try greasing it.
finally, the motor often gets water in because it sits low in the bilge - remove/clean/repair/replace motor.

 

[fabrimacator21]

Re: Need help with jack screw power trim on a 305 omc/omc 800 I/O

Yeah grease would defienetly be a good idea.

For checking voltage drops... can I just put the multimeter on the terminal itself?

Also what do you mean by side terminals? I did pull all the connections at both solenoids and clean em up but it still won't move.

I noticed I can move the motor up and down by screwing/unscrewing the jack screw rod by hand but it doesn't move far until it stops. Doesn't feel like the motor is turning when I'm doing this as theres not much resistance at alll. Could this just be slop? When it stops could that be because of the motor?

 

[Howard Sterndrive]

Re: Need help with jack screw power trim on a 305 omc/omc 800 I/O

by "heavy current side", I meant that if they are clicking, there's no point in cleaning up the small terminals, just the large terminals.
Voltage drop measures difference in potential from one point in a circuit to the next. Usually a 2 person job, as it can only be done while current is flowing.

They say .1V
.1 would be nice, but a 25 year old boat isn't going to be that good unless all terminals are cleaned up
.5V drop would be fine.

 

[fabrimacator21]

Re: Need help with jack screw power trim on a 305 omc/omc 800 I/O

Ok... thanks...

Where are the heavy terminals?

 

[Howard Sterndrive]

Re: Need help with jack screw power trim on a 305 omc/omc 800 I/O

on the relays, right next to the little ones.

The little wires make it "click", then the large wires carry the current to the motor.

 

[fabrimacator21]

Re: Need help with jack screw power trim on a 305 omc/omc 800 I/O

Cleaned all those up and got nothing....

I pulled the motor out today and found one of the wires in the motor was not connected... the connector was so corroded that it just plain fell off. Gonna solder it up and try it see if it works.

I also found out my crankshaft pulley was rubbing on my trim bracket/motor mount. Seems to be loose motor mount studs that caused it. Basically I just found out that I need to do some serious work to my stringers in order to get them solid again. I have a few ideas that could work without actually replacing the stringers.

Thanks for the help.

 

[fabrimacator21]

Re: Need help with jack screw power trim on a 305 omc/omc 800 I/O

Is there a certain marine specific grease that should be used or will axle grease work?

 

[THE BEEF]

Re: Need help with jack screw power trim on a 305 omc/omc 800 I/O

I use OMC triple guard grease on mine. So far no problems. I hope I don't put the dreaded triple pecker pigeon curse on me!
Beef