Help with stalling motor and other issues

[trooper1822]

Hey guys, been out enjoying nice Texas weather and getting some great fishing in. Got the boat running decent enough but still a few issues. So first issue is with the motor. It is a 1988 85hp force mounted on a 88 bayliner bass trophy. So when I run it on the muffs it runs and idles fine. But when I put it the water it will fire up and run for a few min but then slowly idles down and dies. Once it does this it will start back up but dies again unless I immediately put it in gear. But even in gear at creeping speeds it acts like it wants to die. Once I get out of the no wake zone and gas it it goes great. Any ideas? I already tore down the carbs and cleaned them real good, new fuel lines, inline fuel filter and added a fuel water separator. New plugs also. I'm able to get up to 27mph shown on my gps fish finder. Feel like I should be getting into the 30s.

2nd issue is with the navigation lights. It is weird because when I turn them on they will not come on. But if I turn the bilge pump on or hit the trim button they start working. I can turn them on and off just fine. But if I turn them off and come back 5 min later they wont work again unless I hit one of the other switches. Tested the wires at the switches and they are getting power. So i feel like something isn't wired correctly.

 

[trooper1822]

This is running at full throttle. Gps said 28.2

 

[trooper1822]

Also just decided to empty my fuel/water separator for the first time since installing it back in March. Had the boat out around 15 times. Also see some crud floating around in there. Nice to know the filter is doing its job.

 

[Jiggz]

If it runs fine on muffs and doesn't die but chokes and dies in the water, this is an indication of exhaust leak inside the cowling either coming from the idle relief hose or from the bottom seal.

To confirm this try running it in the water with the cover off to see if it smooths out. If it does, then you need to trace where the exhaust leak is coming from.

If it's not exhaust leak, then it could just be a case of a too low of a idle speed setting. Remember in the water in gear, idle speed should be around 700~800 rpm. In neutral out of the water on muffs, 1000~1100 rpm.

 

[trooper1822]

Hmm never thought of that. I noticed when I put it in the water and while waiting for my friend to park the suv, I putt around the launch area and at first it runs fine but after a few min it slowly dies down until it cuts out unless I give it more throttle. Same as when we get to a fishing spot. If I kill it and then try to start again it is a pain to get going. But if we sit and fish for a while and then decide to move, it fires right up and is fine. I'm going out again on Friday and will try like you said. I'm assuming because it is out of the water on muffs the exhaust exits freely vs. the leg being under water and having back pressure. Exhaust possibly building up under the cover and choking out the motor.

 

[Jiggz]

That is absolutely correct. When you have exhaust leaks and the motor is on muffs, it will ran fine without choking. But as soon as you submerge the leg into the water, the exhaust will accumulate in the cowling and eventually choking the motor.

You can also test without going to the water using a large trash bin.

 

[trooper1822]

Ok perfect. I think I have a large can I can use to run the motor on. I'll try tomorrow and see what happens.

 

[trooper1822]

Ok so did some work on the motor today. I disconnected the vacuum line under the intake manifold that runs to the fitting under the number three carb. Inside that fitting is a small orifice and it was totally clogged with gunk. As I have read this can lead to hard starting/using and fuel coming out of the #3 carb. After I installed everything I fired it up and let it run for 10 min without the cover on. Then I put the cover on and let it run. Ran for 10 min and never died. So now i am running it with a gallon of fuel mixed with sea foam. One thing i was wondering is is it normal for this much oil to be in the water or am i running way to rich? I have each carb set at 1 turn out from loosely seated. It does smoke a lot but figures thia is normal. I dont want to lean it anymore as i know 1 turn out is about as low as you should go.

 

[trooper1822]

Also at idle for 15 min running off the one gal can, the motor consumed half a gal. Is this too much?

 

[Jiggz]

Loosely seated is not the proper term when it comes to seating the idle needle. It should seat and should be able to tell if you are just using your forefinger and thumb to do the tightening. And from this you should set it 1 turn out. I am not sure where you got the term vacuum line, but there is no vacuum system with these motors.

Advancing timing is all done mechanically through the timing tower and the trigger plate system. The hose you are referring to is probably the fuel recovery system.

Anyways, if the motor does not die anymore when in water and starting is not as hard. Then you can start tweaking it by ensuring the idle rpm is correct and the idle mixture screw setting is also correctly set.

 

[Jiggz]

Another thing you might want to check regarding the "vacuum line" you are referring to is that maybe this is the choke system. There are basically two common types choke systems used on Force motors. One that uses a solenoid to flip a "butterfly" and one that uses also a solenoid to open and close a fuel line.

The "Butterfly" type is easy to determine if it's working properly or not but not the solenoid fuel type. The most common problem with this choke system is the solenoid not closing properly thus keeping the system "choked" (too rich of fuel mixture). A quick check by pinching the fuel line feeding this choke system can confirm such problem.

If you can post a pic of the location of the hose you have in question, it'll help in id'ing it.

 

[jerryjerry05]

The 88 used the old style choke.
The fitting he's talking about is the fuel recovery line from the plenum.
Keep it clean.

The carbs need to be set at 1 turn out(per the factory) BUT!! some 85's run crappy unless they are out more.
One of my customers his needed to be out almost 3 turns before it started???

Do a compression and spark test?
Check the trigger leads, wire is very thin and breaks easily, under the shrinkwrap it can be broken and still look good.

Does the ball pump up hard?
Does it go soft.
It should get soft after starting.

Excessive fuel use:, bad fuel pump.

Seafoam, it's like adding soap to your fuel, does nothing(my opinion).
If you want to do something use Mercury's Power Tune or OMC's Engine Tuner.
The only additive you need is Sta-bil or maybe an ethanol stabilizer but only if your gonna let the
boat set for extended periods.
The very best thing, keep it full when not in use.

 

[trooper1822]

Sorry I was out fishing today and enjoying the lake. So update. Boat is now idling fine and not dying when put into gear or just idling. So think that is fixed. New problem I'm having. Well two. First, the neutral kill is acting up. I have to hold the throttle back while turning the key to start the boat. The other issue that is more serious is my reverse is acting up. It has worked without issue and today when I was out I would try and go into reverse and it made the grinding noise but would not fully go in. Only way I could get it to go in was to rev it real fast to almost max reversing power and it would catch. Going to drain the lower unit tomorrow and hopefully no shavings. Dont think there will be as it only did this 3 times and then I just avoided situations where I needed reverse.

Also my last compression check was like the high 120s if I remember correctly on each cylinder and they were all close to each other. Was about 3 months ago. I tested all 3 spark plugs and got good spark on each. Rebuilt the fuel pump 3 months ago and installed a new diaphragm. New ball and it pumps hard and does get soft after running.

when I set the carbs 3 months ago I tried going further out and it ran worse but when I went in it ran better. When i actually bought the boat the previous owner was running it at less than 1 full turn out. I reset it when I rebuilt the carbs. And just to make sure, out would make it more rich and in would be more lean.

 

[trooper1822]

With the motor off I can spin the prop by hand in neutral, shift it to forward and cant spin it, shift to reverse and it acts like it is close to engaging but doesn't. Makes a clicking noise but still spins.

 

[jerryjerry05]

Read the top 3 posts in this forum.
I believe one has a linc and sync post.

It sounds like the N safety switch needs adjusting.
And the shift linkage needs adjusting.

U tube has some good video's.

 

[trooper1822]

Ok so did the linc & sync again and in the process discovered why I was not getting full speed. So the last time I did it I must have messed up somewhere because when I took the intake manifold off and looked down the carbs, the butterfly's were not fully open when in full forward or reverse
they were barely opening up. So that would explain the low speed issue. Redid everything and took my time and now they fully open and close as they should. Now I'm going to reset the idle. Also think I fixed the reverse issue. The cable needed to be adjusted. Made some adjustments and now it locks in when I put it in reverse. Seems to also have fixed the neutral kill. Turns over with every turn of the key now. But new issue Is my tilt/trim pump is leaking. The deal that makes the pump is worn out and sits flush with the metal surface. Fix one issue and a new one pops up.

 

[jerryjerry05]

What does this mean??
"The deal that makes the pump is worn out and sits flush with the metal surface."

Where's it leaking?
​

 

[trooper1822]

Sorry, auto correct. Ok so there are 4 bolts that hold the pump on, remove them to take the pump off and there is a rubber seal on the bottom of the pump. That seal is worn. When I bolt the pump back down and fill with fluid and cycle the tilt/trim, fluid seeps out around the mating surface.

 

[jerryjerry05]

Ok
Too bad I just got rid of a bunch of seals

I'll look and see if I might have one.
I think this is the part#

O-RING F17522