86 Force tilt cylinder leaking. Advice needed.

Zink357

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I have an 86 Force 125hp and I just tore apart the tilt and trim cylinders and replaced all the O-rings in them. After putting everything back together and bleeding it, everything is working except there is a leak from the hole in the top of the tilt cylinder where the down line connects to it. There is a metal strap around the cylinder and a fitting that screws into that strap which is just supposed to hold the fitting tight to the cylinder. I have that tightened as far as I dare and it is leaking around where that fitting meets the cylinder. If the pic inserts properly, I marked it with the black arrow. I am wondering if I just need to file it down so its smooth and use a drill bit to smooth out the countersunk part as it seems a little rough around the opening and it isn't sealing properly? I'm a little afraid to go at it like that and wreck it completely. Anyone ever had this problem or have any ideas? The fitting is not threaded all the way into the metal strap yet so I know it's not just loose because that bottomed out. I'm stuck here. It's not leaking like crazy, but it's leaking regardless.
 

Zink357

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Here’s the pic of what I’m talking about.
 

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jerryjerry05

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The strap fitting, banjo fitting.
Try to loosen and tighten again.
The wall of the cyl. is very thin and trying to drill it out will probably end in disaster??
Check the banjo fitting for grooves and burrs.
You'll probably end up getting new.
 

Zink357

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Yeah I agree it could end in disaster. I just thought if it wasn’t smooth I could very lightly hit it with a bigger bit to make it smooth. I’m worried it might be the hole in the cylinder and I’ll have to replace the whole cylinder.
 

jerryjerry05

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If the new banjo fitting doesn't do the trick?
I might have a cyl.
It's yours if I have it, BUT!!
You pay shipping and donate 25$ to an animal shelter.
Let me know.
It will need a new banjo fitting.
So try the fitting and if it still leaks, I'll see if I have the cyl.
 

Zink357

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You’re awesome! That’s a deal. I’m going to pull it apart today or tomorrow and see if I can fix it then I guess I’ll have to find a new fitting if it doesn’t work. Thanks!
 

Zink357

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I cleaned up the fitting and ran a chamfer bit in the cylinder hole. I couldn’t get the cylinder hole perfectly smooth but I got it as good as I could without risking going too far and it’s much better now, but still has a small leak. I might try to find a better bit but it rattled around too much with the drill I’m using and cutting into aluminum. Still going to work on it some more.

Side question: I had it out on the lake today and at WOT the tach was showing 7200+ RPMs. Is that legit or is my motor about to explode?
 

jerryjerry05

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Your motor's capable of 9k and more.
The 5500 is suggested as optimum and keeping the motor together.
Get a Tiny Tach or something similar.
I paid 20$ for one on eBay
Then hook it up?

1986 125
What prop? Boat size?
 

Zink357

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I’m not sure of the prop, is the size/pitch stamped on them? The boat is a 18’ thundercraft and weighs like 1300lbs empty. I will probably do that. Motor runs strong and sounds good. I just wasn’t sure since the tach only goes to 8k. Thanks again!
 
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jerryjerry05

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It should have a # someplace on it?

Might have a 17 19 or a 3 # code maybe a 5 digit code?
Look under the nut and spacer?
 

VivaLaMigra

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Well, you're down to a little weeping, so maybe it's time to resort to the ol' JB Weld. It's no miracle cure but I have had it hold on pinhole leaks on a trim pump. If you got 90% of the original leak, and the JB Weld gets 90% of the remainder, you're probably in the "I can live with it" territory" until you score another tilt cylinder,. and they aren't an extinct species - after all you only need the cylinder and I just may have a good donor. As for RPM, a Chrysler with heavy dome pistons isn't built to turn seven grand so if the thing sounds like it's screaming then you either have too flat a prop or a slipping hub. Yeah, fix that before you put a rod through the block. Check that the tach is set to the right pulse-per-revolution setting, too. If the tach was used with a 3-banger it's going to read 33% high.
 

Zink357

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Well, you're down to a little weeping, so maybe it's time to resort to the ol' JB Weld. It's no miracle cure but I have had it hold on pinhole leaks on a trim pump. If you got 90% of the original leak, and the JB Weld gets 90% of the remainder, you're probably in the "I can live with it" territory" until you score another tilt cylinder,. and they aren't an extinct species - after all you only need the cylinder and I just may have a good donor. As for RPM, a Chrysler with heavy dome pistons isn't built to turn seven grand so if the thing sounds like it's screaming then you either have too flat a prop or a slipping hub. Yeah, fix that before you put a rod through the block. Check that the tach is set to the right pulse-per-revolution setting, too. If the tach was used with a 3-banger it's going to read 33% high.

It's supposed to rain here tomorrow so I think I will tear it back apart and attempt to smooth out the mating surfaces and try your JB weld idea as well. As for the engine, I adjusted the timing and messed around with it til I got it running as good as possible. Have had it out on the lake a couple times since and it is maxing out just over 6,000rpms so I think I am good to go there.

Thanks everyone for the help so far! I will update when I get the tilt issue under control. Probably going to build a livewell for this thing tomorrow too. If I can find room to hide it!
 

jerryjerry05

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If you can get 6K then it's still not propped right??

The lightly loaded, 1/2 tank of fuel and Coastguard equipment and 1-2 people the motor should run at 5500.

The tach you sure it's right?
They sell a test tach, Tiny Tach or equivalent, I got one that cost 16$ and is 6-7 years old.
Just make sure you get one that you can replace the battery.
 

Zink357

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So I bought a better chamfer bit and got the hole really smooth and I decided to use the JB weld on it at the same time so I wouldn't have to pull it back off again and so far it has stopped leaking, BUT... The damn thing is still slowly leaking down. Will this happen if there's still air in the system and its not completely bled out? I believe it is a self bleeding system is it not? I ran it up and down several times and then let it sit for awhile and then up and down a bunch more times, but still slowly leaks down exactly the same as before I replaced all of the O-rings. What gives? I couldn't get the cylinder cap off the shock absorber cylinder (the one without any hydraulic lines) to replace the O-rings on it so I just left it. Could that be my issue? IDK how I'd get that cap off. The holes on the top have ripped thru so I cant use a spanner on it and I even gripped it with a vice grip trying to get it off but won't budge.
 

jerryjerry05

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The leakdown isn't in the cyl.
The bottom of the pump has 2 valves.
Look/read the posts in the first 4 posts in this section.
One covers the repair/replace of the seals in the valves.

There is a leakdown test in the posts too.
 

Zink357

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Thanks jerry, ordered the parts! I knew the stickies were there too. Just really thought it was the tilt cylinder since it was leaking out the top.
 
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