1990 Force 120HP trim and tilt not keeping motor up no leaks

gica

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Feb 24, 2016
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So I rebuilt this motor successfully. I have a fual motor on my 24 footer. And after I raised it up it slowly started sliding down. It foes stip but too low for confort. The other one slides down only half way. There are no leaks on the outside anywhere. So I read and bought some cylinder kit for trim tilt and shock, but after reading some more I found out that the pump is most likely the culprit. So I wanted to know where I can get some o-rings and info on what to do so I do not screw things out.
I read every post with thos issue beforehand. There was mebtion of some brighs carb kit that includes the small rings. Didn't find the part number.
I did find some ebay listings for pumps for 80 bucks or so but I don't know how reliable they are.
 

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brodmann

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I can't understand a lot of your typing, but I purchased a tilt/trim motor "pump" for my Yamaha 115 4 years ago, and it's still working fine. Mine just stopped working one day. Raise the motor up all the way and remove the fill plug and fill it with oil. Some take a standard 30 weight oil, others recommend transmission fluid. If you can hear the motor working, but the motors aren't going up and down all the way, then I'm pretty sure the o-rings in the cylinders need to be replaced. All the motor does is pump the hydraulic fluid where it needs to go. If it's turning and pumping but things aren't working correctly, the cylinders most likely need to be rebuilt because the fluid is making it past or around the O-rings.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Your pump either has bad load holding check valves, or your cylinder seals at the piston are leaking
 

gica

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Yeah sorry for the typos auto correct on the cell is the cause. So the motor works it drive it up, but it immediately wants to slide back down. I know there are seals for the shock plus tilt trim which I already have, but upon reading more into it there seems to be the check valves seals in the pump at play. The
Sticky on this forum mentions the carb kit that includes really small o-rings for the pump to be rebuild. It's written for an 85 HP though. Hope it works for my 1990 Force 120HP, pumps might be similar.
Jerry? Help
 

Nordin

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If you have not read the Force & Chrysler FAQ in top of this forum read it first before digging into the T&T.
Pnwboat, jiggz and jerry are the guys right now that knows the T&T best.
 

jerryjerry05

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May 7, 2008
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The shock does nothing about keeping it up.
All it does is give it some resistance when going down and no bouncing around.
The drifting down is due to the seals in the bottom of the pump.
The 4-5 posts in the first part of this forum(#4) covers the T@T and can lead to where to buy the seals.
CAUTION!!! if it's been in salt water it will probably be real hard to dismantle.
The pump itself: there is NOTHING in the actual pump that you can work on so leave it alone. The nut and screws can not be adjusted. So DON'T TOUCH!!!
Somone on here was willing to send the seals for free?? Maybe they'll see this and make the offer again.
The cheapo Chinese(junk) pumps are just that But for 40$ what do you expect??
They might sell them here(can't find it) but https://maxrules.com/quoteform/form2.php has a good one.
 

topgun3690

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May 7, 2019
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Still got a few......PM if interested. Briggs & Stratton part# 398188. Not a problem if you are in the lower 48. And you only need two (2).
 

gica

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Feb 24, 2016
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393
Is the thumb picture the 398188 seal? And it takes 2?
 

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gica

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Still got a few......PM if interested. Briggs & Stratton part# 398188. Not a problem if you are in the lower 48. And you only need two (2).
I am , since I need it. Trying to figure out the PM part hahaha
 

jerryjerry05

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To start a PM Click on the persons name. Then look for the spot that says start a conversation. Thats all it takes.
 

gica

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Feb 24, 2016
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393
Ok so the motor runs great but it doesn't go in gear. When I put it in gear with engine off and spin the propeller by hand it doesn't spin the pistons like the other one does. Wtf. I remember when I was rebuilding the engine I did that and it was the same, no spinning. But I ignored it. I don't think it's from the top end. The propeller locks when I put it in gear but doesn't spin the main shaft so doesn't spin the engine. Before I rebuilt the engine it was working fine drove it on a lake no issues. What could happen while sitting.
Spun hub!? How?
 

jerryjerry05

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You didn't change the drive did you?
Put a shorter drive shaft lower unit on.?
You hookup the linkage at the front of the mid section?#12
1689934256171.png
 

gica

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Feb 24, 2016
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393
You didn't change the drive did you?
Put a shorter drive shaft lower unit on.?
You hookup the linkage at the front of the mid section?#12
View attachment 385258
I did not touch the drive. So the main shaft is not being turned by the drive. With engine off when I put it in forward or reverse the propeller locks as it should when turned one way and when I spin it the other way it feels a little heavy as if the drive is engaged but not as heavy as the second engine feels because it is not spinning the main shaft to turn the crank. So whatever is wrong is at the main shaft level. I checked movement of the shifter rod on top at the #15 nut and it is the same as the 2nd engine.
Again it engages the drive but not the main shaft.
Could it be that I pulled the shaft out of where ever it goes the forst time I pulled the engine?
 

gica

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OK so I pulled the drive and before I did that. I drained the liquid Inside and surprise surprise there was water with a little bit Of fluid luckily it was only lake water. I removed the propeller and the shaft inside I didn't see any rust
I looked at the spines in the crankshaft and they look fine.
I saw o rings In several places Including the lower shaft.
Now when I when I lower the gear link Rod And spin the propeller It seems to engage the main Shaft
 

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gica

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So I took the drive apart. Need some bearings and seals
 

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Nordin

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Now when you have the LU apart check the clutch dog.
It is the clutch dog that make the shifting from forward and reverse and vice versa.
The edges at the clutch dog teeth should be sharp and perpendicular not rounded.
If they are rounded it maybe slip out of gear under load.
 

gica

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Feb 24, 2016
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393
Now when you have the LU apart check the clutch dog.
It is the clutch dog that make the shifting from forward and reverse and vice versa.
The edges at the clutch dog teeth should be sharp and perpendicular not rounded.
If they are rounded it maybe slip out of gear under load.
Will do
So there are 2 bearings one on the main shaft which was definitly full of crud and the other attached to the reverse gear don't know if it is salvageable.
That one is big. I cannot find a part number for it. Any ideas?
Here are pics of the bearings and clutch dog(I think)
 

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