1994 Force 120HP won't Trim up while under throttle

[res0n0xg]

Hi Guys, complete boat newbie here to be honest. Just got a used boat and now the fun has begun! I replaced both relays as sometimes the motor wouldn't trim up at all, you could just hear that distinct clicking coming from the relay. This was during any use, whether parked, neutral, etc. After replacing both relays the trim up issue seemed resolved as while not moving, the boat trims up and down without issue, no hesitation, etc.

Now, again, I am ignorant somewhat still, but it sure doesn't seem to trim up at all while under medium throttle and above.


What would be some basic things to check out before I sucked it up and forked over lots of $$ on this weird issue?

 

[jerryjerry05]

Re: 1994 Force 120HP won't Trim up while under throttle

What type trim do you have?
They used 2 motors on that year??
You checked the fluid?
The unit is supposed to trim to a certain point.Then the tilt takes over.
It doesn't have enough power to go past the tilt while going fast.
Does it trim up while underway?

 

[Jiggz]

Re: 1994 Force 120HP won't Trim up while under throttle

At higher speeds it takes more force to trim up but you can always trim down. I avoid trimming up at high speeds as it is very slow due to the opposing push by the engine. If I need to trim up I make sure I am no more than 2000 RPM in forward gear.

 

[res0n0xg]

Re: 1994 Force 120HP won't Trim up while under throttle

What type trim do you have?
They used 2 motors on that year??
You checked the fluid?
The unit is supposed to trim to a certain point.Then the tilt takes over.
It doesn't have enough power to go past the tilt while going fast.
Does it trim up while underway?

Wow thanks for the quick reply's!

Anyway, I do not know what type of trim I have and would be happy to tell you if you can tell me how to distinguish the two, I have not checked the fluid yet, I'm assuming this is easy?


Like I said, I'm fully ignorant at this point, but am learning slowly and feel like maybe I am expecting the thing to trim up at higher speeds when it really shouldn't be. I'm just have a hell of a time trying to get the boat on plane at higher speeds and thought trimming up would help level it out.


what do you mean trim up when "underway"



Also, one last thing I have forgotten, is after being out on the water and trying to teach my wife how to drive the boat without killing the motor I got an alarm sound for a minute or so, which I'm assuming is a basic overheat alarm. Maybe we had the motor up too high as the water was choppy yesterday due to wind so it's possible it wasn't getting enough water, but is there a way to check flow through the system? Where would the peaholes be on this motor as I didn't see where the water is supposed to be coming out.

 

[RRitt]

Re: 1994 Force 120HP won't Trim up while under throttle

make sure all electrical connections are clean and secure. the motors don't have much extra power and a single bad connection can make your trim too weak too lift against much horsepower. if all the wiring is good then motor might have gotten oil or water in it and is running weak. if you need new motor Arco makes the best ... but $$. china motors are cheap but have serious galvanic issues. make sure you install a ground strap directly from base of motor to an anode.

 

[res0n0xg]

Re: 1994 Force 120HP won't Trim up while under throttle

make sure all electrical connections are clean and secure. the motors don't have much extra power and a single bad connection can make your trim too weak too lift against much horsepower. if all the wiring is good then motor might have gotten oil or water in it and is running weak. if you need new motor Arco makes the best ... but $$. china motors are cheap but have serious galvanic issues. make sure you install a ground strap directly from base of motor to an anode.

To the best I can see all wiring looks pretty good actually, no corrosion, fraying, exposure, etc. I'll keep that in mind on the motor, but I really don't think that is the issue, at least for now.

 

[JPatterson350]

Re: 1994 Force 120HP won't Trim up while under throttle

To the best I can see all wiring looks pretty good actually, no corrosion, fraying, exposure, etc. I'll keep that in mind on the motor, but I really don't think that is the issue, at least for now.

Sounds to me like you may have a bad oring in the trim cylinder this is directly under your motor I started having this problem and eventually my entire system stopped working until I replaced the orings.

 

[RRitt]

Re: 1994 Force 120HP won't Trim up while under throttle

Sounds to me like you may have a bad oring in the trim cylinder this is directly under your motor I started having this problem and eventually my entire system stopped working until I replaced the orings.

bad cylinder orings will leak down even with engine turned off and on a trailer. if it won't trim up with throttle but holds position then motor torque is the #1 suspect. If it slams down on throttle then it would be a ram or pump issue.

 

[jerryjerry05]

Re: 1994 Force 120HP won't Trim up while under throttle

Post a pic.

As for trimming under power:
My boat,drives all the way down,I accelerate and get on plane.Then as I speed up, I trim the motors to raise the nose.
The pump should have no problem trimming it at ANY speed.

If you have trouble getting on plane ,do a compression test.
Profile? Location?
Guessing you have the standard Prestolite system.
Check oil level:motor down,undo screw see if oil comes out.
Should be regular motor oil.Someone suggested using a ketchup dispenser/bottle to add oil(great idea).
Add oil until it comes out.Thenscrew back in,and cycle the unit.
Then leave it all the way up and see if it comes down on it's own???

 

[res0n0xg]

Re: 1994 Force 120HP won't Trim up while under throttle

Post a pic.

As for trimming under power:
My boat,drives all the way down,I accelerate and get on plane.Then as I speed up, I trim the motors to raise the nose.
The pump should have no problem trimming it at ANY speed.

If you have trouble getting on plane ,do a compression test.
Profile? Location?
Guessing you have the standard Prestolite system.
Check oil level:motor down,undo screw see if oil comes out.
Should be regular motor oil.Someone suggested using a ketchup dispenser/bottle to add oil(great idea).
Add oil until it comes out.Thenscrew back in,and cycle the unit.
Then leave it all the way up and see if it comes down on it's own???

So you start with the motor all the way down? I probably just have a problem getting on plane because I suck at driving boats...

Compression is good and strong on all 4 cylinders, I was there and got to see that my self. Looks like first order of business is to check the oil, which I'll do today and snap a picture or two.


So for the oil level.... If nothing comes out when I undo that screw it's low? I can see orings being an issue I guess but I see no leaks on my driveway, nothing on the trailer, and notice no residue on the motor either so unless it's bone dry I'm not sure that would be it.

Thanks again for all the suggestions, I would hope it would be something as simple as orings or just low oil.

 

[jerryjerry05]

Re: 1994 Force 120HP won't Trim up while under throttle

Over time oil gets used on the rams and tilt.
No leaks is a good thing!!

 

[emoney]

Re: 1994 Force 120HP won't Trim up while under throttle

Definitely keep her trimmed down to get on plane, then use your trim to raise the hull a smidge for best performance. If you're porpoising, that's when to hit that trim switch up or down. Lower is torque, higher is horsepower (that's how I learned what trim was about). As to your overheat, best suggestion I received on here (well, equal to the best anyway), was to purchase one of those infrared thermometers. I picked one up at harbor freight pretty cheap. You can shoot a temp reading on your heads and then you can be accurate to see if she's overheating/t-stat opening, etc. Odds are, she buzzed because you did, in fact, have it too high in the water. A little chop can cause your prop to come out when it's all the way down, let alone all the way up.

 

[res0n0xg]

Re: 1994 Force 120HP won't Trim up while under throttle

Definitely keep her trimmed down to get on plane, then use your trim to raise the hull a smidge for best performance. If you're porpoising, that's when to hit that trim switch up or down. Lower is torque, higher is horsepower (that's how I learned what trim was about). As to your overheat, best suggestion I received on here (well, equal to the best anyway), was to purchase one of those infrared thermometers. I picked one up at harbor freight pretty cheap. You can shoot a temp reading on your heads and then you can be accurate to see if she's overheating/t-stat opening, etc. Odds are, she buzzed because you did, in fact, have it too high in the water. A little chop can cause your prop to come out when it's all the way down, let alone all the way up.

Well, checked the oil with the motor trimmed up (that's what the big warning label said to do) and it spilled out immediately upon loosening that screw.

what type of oil is that? seemed thinner than regular motor oil but not like ATF?

 

[RRitt]

Re: 1994 Force 120HP won't Trim up while under throttle

1994 Force 90-150HP

if the fluid is red then it is a type of ATF. If the fluid is tan then it is a type of hydraulic oil. If the system stays lifted in your garage then the rams are okay. If the system falls as fast as the pump can lift then the trim cylinder is probably blown. if the system lifts and drifts down then you'vwe probably gotten debris into the pump. if the system holds in the garage but falls on throttle then you've probably gotten water into the system and rusted out a spring in either tilt ram or hydraulic pump. If tilt ram is bad the top seal is not replaceable. If top seal is cracking (how the water usually gets in) then it is cheaper to throw away ram and replace with chrysler type design. to get new top seal it has to be custom made. last quote i got required 500 piece run which is about a 50 year supply.

 

[res0n0xg]

Re: 1994 Force 120HP won't Trim up while under throttle

1994 Force 90-150HP

if the fluid is red then it is a type of ATF. If the fluid is tan then it is a type of hydraulic oil. If the system stays lifted in your garage then the rams are okay. If the system falls as fast as the pump can lift then the trim cylinder is probably blown. if the system lifts and drifts down then you'vwe probably gotten debris into the pump. if the system holds in the garage but falls on throttle then you've probably gotten water into the system and rusted out a spring in either tilt ram or hydraulic pump. If tilt ram is bad the top seal is not replaceable. If top seal is cracking (how the water usually gets in) then it is cheaper to throw away ram and replace with chrysler type design. to get new top seal it has to be custom made. last quote i got required 500 piece run which is about a 50 year supply.

It definitely stays up on it's own without issue. The concerning part is the falling on throttle though, which I'm not sure it does.... But definitely what i'll keep an eye out when I get it back out.

Also, the fluid was black and seemed very much like a regular oil, is that not normal?