how to replace 98 force 120hp tilt motor ?

[Bustedknuckle84]

new to the boat world. Im a decent mechanic just cannot get enough info for replacing the tilt motor for my 98 force 120hp 2 wire design. I show the arco motor is the 6276 design.

However i see a fill plug and a drain plug at the bottom of this motor. Does anyone have directions on how to replace the motor and what oil is used to fill it with? thankyou guys for your help in my research.

 

[RRitt]

Re: how to replace 98 force 120hp tilt motor ?

lift engine and block in place. disconnect wires and feed back out of engine cowl. remove continuity strap between trim motor and anode. punch out lower mounting pin. swing unit up and punch out upper mounting pin. remove unit from boat. slowly loosen filler plug to release pressure. rock unit back and forth and dump out most oil from reservoir. replace filler plug and seat but do not tighten. clamp piston shaft mounting eye in vice so that unit is upside down. remove four bolts securing motor reservoir to manfiold. Reservoir will still have oil in it so keep motor upside down. get new motor. use 3-4 very small dabs of super glue to hold gasket in place. If it comes out of groove during installation it usually gets pinched and broken. use old driveshaft is new motor is same as old. If not, carefully select correct dirveshaft from install kit before proceeeding. the rest of process is reverse of above. If you are having any hydraulic problems this is a good time to address them as well. a cylkinder rebuild kit is fairly simple. I've never sold any, but if i did, they would be under $30 for sure. If you have the spanner wrench and your system is off the boat then it takes less than an hour. Getting piston off of shaft can be tricky. Clamp it vice from top to bottom rather than around edge - use a nice long breaker bar. Otherwise simple. No need to hone. Inside of housing is anodized.

 

[Bustedknuckle84]

Re: how to replace 98 force 120hp tilt motor ?

i couldnt have asked for better directions thankyou times amillion!

just have another question though, you said hydraulic problem only thing i noticed was the alittle bit of fluid coming out of the top of the hydraulic pump smells like tranny fluid maybe dextron 3 however do you recommend to do the rebuild kit on the cylinder?

 

[RRitt]

Re: how to replace 98 force 120hp tilt motor ?

whether to rebuild the ram or not is up to you.

Mercury has been using your system since 1988 on most of their Merc & mariner 120HP and smaller engines. This system is actually not as good as the 197x-1992 prestolite. It is an easier system to repair than the Force but it costs a lot more to make and doesn't last nearly as long. While the Force system routinely goes 20-23 years the Mercury system seems to have problems around 15. If you rebuild pump & ram at the same time as putting on motor then you should be good to go until sometime around 2025. If you replace the motor then you have a 50/50 shot of going back in for a pump sometime in the next 5 years. If it was my boat and I was putting it away for winter then I would rebuild the ram. That way i could see how much rust has formed around the trim spool and gauge whether or not to expect pump problems while also putting a new seal on the piston shaft to prevent future water intrusion.

 

[Bustedknuckle84]

Re: how to replace 98 force 120hp tilt motor ?

rritt i couldnt thankyou anymore for taking the time to give me this info. Ill try to update after this tuesday with my results.

 

[Bustedknuckle84]

Re: how to replace 98 force 120hp tilt motor ?

bump with update:
installed tilt motor however the hydralic pump isn't working. I hear the motor spinning but no movement from the pump regardless of lowering or raisng the motor. . Can i get instructions on how to fill the the resevior after installing the unit. . I spent few hours trying to get the hydraulic pump to work no luck. i dunno if theres air in the hydralic pump or what.
heres what the parts look like;
http://www.dougrussell.com/partscat...6,13,20,8,17,18,2,3,23,19,7,5,4,14,21,22,9,15

 

[RRitt]

Re: how to replace 98 force 120hp tilt motor ?

were you careful to put in the right drive shaft? As regards filling - do it before attaching lower pin so that you can fill at any position. Run system up and down a few times while adding fluid. System is self bleeding and trapped air bubbles are of no consequence. Correct fluid level is to bottom of filler hole while fully extended.

 

[Bustedknuckle84]

Re: how to replace 98 force 120hp tilt motor ?

were you careful to put in the right drive shaft? As regards filling - do it before attaching lower pin so that you can fill at any position. Run system up and down a few times while adding fluid. System is self bleeding and trapped air bubbles are of no consequence. Correct fluid level is to bottom of filler hole while fully extended.

there were 3 sizes i used the same size that came off the old motor. I see the shaft spinning while looking through the fill hole while moving trim up and down. However im not able to run it up and down by tilt switch motor spins but no movement.
When you say its self bleeding do i keep the manual valve thats on the side of the motor slightly open or closed?
do i keep the fill cap off during the filling up process?
the problem is when i have the fill cap open and manhandle the motor down it seems to take fluid in then moving it up spits the fluid out of fill hole.

 

[RRitt]

Re: how to replace 98 force 120hp tilt motor ?

if the motor style changed then the shaft has to change also. If you are positive that the gear is engaged and the system does not move when the motor spins then there are 3 possibilities:

1) no fluid in reservoir
2) release valve not seated. It should be seated but not torqued. You can permanently damage system by applying too much torque to the nylon release plug.
3) pump is busted

rebuilt is better. mercury wants the deed to your house and rights to your first born in exchange for a new one.

 

[Bustedknuckle84]

Re: how to replace 98 force 120hp tilt motor ?

thankyou for all your info rritt, turns out that even though the motor was the same design the drive shaft needed to be longer. i replaced with the same size drive shaft and that was the problem. $150 mistake but a $150 learning lesson.