89 Force 50HP turns on and stays on only on high idle start

[Eddie Rivera]

1989 Force 50 HP 507X9B

I mixed a gallon of fresh 91 octane and 2.6 oz of oil and 1/4 can of sea foam to decarbonize the motor since I have not turned it on for almost a year - on a carburetor with a new main niddle, a new float and gaskets and let it sit there and run "with the motor cover on"

Everything was going great until I -
---put it into forward gear and went full throttle with no propeller on.
Then as I brought back the shifter to the center slowly it just turned off and it would not start again.
I cranked it for a long time using choke and used some starter fluid even, after a real long time it started again but only on neutral high throttle.

--- I felt the motor kinda hot. Noticed the water tank level was too close to the lower leg water inlet hole. I put the the earmuffs specifically for this motor and put it back in the tank full of water as a backup.

Now it stays on but only giving it some throttle.

I mixed a new gallon of fuel but only with oil and no sea foam - and still won't stay on. I messed with the air mixture screw and did no good so I put it back to one full turn back from seat.

P.S. Last year at te lake in my first run I gave it full throttle and only did 10 miles PH and would not stay on with motor cover and also turned off when I brought throttle back and would not turn on. But then I had a horrible leaking exhaust gasket and loose carb hose clamps and I was about 3500 feet above sea level.

Please help!

 

[MickLovin]

Re: 89 Force 50HP turns on and stays on only on high idle start

Have you done a compression test on it since you think you overheated it? Do you have spark on both plugs? Why did you go full throttle with no prop on, it is bad enough with a prop on, when the test these motors and go full throttle, they use a test prop which will put a load on the motor, running it at full even with a normal prop on can do damage. When you put an outboard in a tank it is best to have the water level at least above the water pump height, if you are just going above the inlet you are asking for trouble.
So 1. check comp 2. check spark, 3. Is your fuel primer getting hard?

 

[Eddie Rivera]

Re: 89 Force 50HP turns on and stays on only on high idle start

Thanks for responding.
Trust me! - I feel so stupid and horrible! Specially after working on it for so long and doing so many things to it.
I made a stupid mistake and I did not know it would damage anything.
I did not test anything else after I stopped. I will check on my compression in a few hours in the morning. It's 3 am right now. Last week I checked it with 2 different testers and I got about 93 lbs on each cylinder.
I assume I get spark because it starts, even though I need to start it in fast idle start.
Bulb gets hard. Should I still check the fuel pump and maybe change the diaphragm and gaskets as a maintenance?

What exactly is the damage that I caused? So it's not a simple matter of idle speed? Is my motor done?

 

[MickLovin]

Re: 89 Force 50HP turns on and stays on only on high idle start

No if it is starting in high idle it maybe just an adjustment with your points, when it runs is it running on both cylinders?
You may have not caused any damage so don't panic yet, check comp and spark on both, check your points to make sure your timing is ok.
If it is running ok at fast idle it but not at idle, could be just an adjustment gone out of wack, or your carbie may just be blocked up.
As I say don't panic yet, if it still has good comp, its probably something simple.

 

[pnwboat]

Re: 89 Force 50HP turns on and stays on only on high idle start

Have you adjusted the idle speed screw? Take a look at this picture below. This is not the exact same motor as yours but similar. Yellow arrow points to the idle speed adjustment screw.



Like Mick says, do your compression test first.

 

[Jiggz]

Re: 89 Force 50HP turns on and stays on only on high idle start

As mentioned, before going on any further, do a compression test. The test of 93 PSI two weeks ago sounds too low. Was this before or after the seafoam run?

 

[Eddie Rivera]

Re: 89 Force 50HP turns on and stays on only on high idle start

Ok guys these are my findings.

- The compression test that I did last year was 93 pounds the compression I did yesterday was for 90 pounds on both cylinders I have lost 3 pounds.
-- I adjusted the idle speed with the top screw on the throttle tower and moved it in 1/4 turn and it idled rough but eventually died.
--- after installing the compression tester and installing new spark plugs I noticed that the spark plug would not fit tightly so the hole on the cylinder plate is ruined, so I thought I would repair it and put an insert and glue it with the proper silicone however someone told me not to do that because it will eventually blow out the sparkie.
---- I was going to remove the cylinder head plate to properly fix the hole with the insert and prevent metal shavings to enter the cylinder so I decided to pull out the cylinder head plate because I wanted to replace the cylinder head gasket anyway and it would also allow me to take a look at the cylinder's condition

This is what I found:
There was a little bit of metal shavings possibly from the bad threading of the spark plug also there was a little bit of debris I think it's from the removal of the screws holding the plate I think it's the corrosion in them. The most important thing I found was that the middle screws holding the plate were not as tight as all the others and I found signs of water in the little work cylinder it was milky combination at first I thought it was the water from the water passages but that leaked out and also showed up in the front of the cylinder, so there is evidence of water in the lower cylinder and I think that is from the face of the cylinder being chipped in two different places one of the chips is halfway thick, The gasket seems to be the original one because all other gaskets on the mortar have blue silicone and this one this not so if this is the original maybe it's not holding enough pressure and it's allowing water to enter the cylinder through that small chip.

----- The cylinder itself is very smooth even to my wife's delicate hands she said they have no grooves or palpable scratches.

I feel that I can replace the cylinder head cover and replace the gasket but I'm afraid that chip may continue letting water in or may do so eventually or even worse completely break off on the chip at the cylinder's face so I feel I have hit a dead end proving that the threading of the spark plug hole the mild looseness(not loose just not as tight) of the middle bolts holding the plates and the gasket plus the chip may have been the cause for the low compression.
I'm stuck. I welcome all suggestions. Will include pictures and video.

 

[Eddie Rivera]

Re: 89 Force 50HP turns on and stays on only on high idle start

 

[Eddie Rivera]

Re: 89 Force 50HP turns on and stays on only on high idle start

 

[MickLovin]

Re: 89 Force 50HP turns on and stays on only on high idle start

Sounds like it is idling too low for out of gear idle, in forward it should be 750 rpm but out of gear around 900 - 1000 rpm. That motor is idling way too low have you a tacho?

 

[Eddie Rivera]

Re: 89 Force 50HP turns on and stays on only on high idle start

No tachometer - it's not even idling - it won't idle, what you see and hear is the motor on neutral with some throttle up.
Did you see the pictures? Did you see the chipped part with the red arrow? What would you suggest as a next step?

 

[Jiggz]

Re: 89 Force 50HP turns on and stays on only on high idle start

From the sound of the engine it is misfiring and probably only running on one cylinder as indicated by the clean spark plug. Double check both plugs to make sure they both have sparks in them using a spark tester. This is the main reason it will not idle.

If it were me this will be my plan of action:
1. Clean the top of the head and especially the top of the cylinder. DO NOT GRIND, use brass or copper wire brush (DO NOT USE STEEL WIRE BRUSH) if you must or some fine sandpaper to remove dirt but not sand the head's metal surfaces

2. The chip on the cylinder top you highlighted are not really at critical point at this time. I do not believe welding them will add anymore structural strength as it is really small. You can however fill them up with some high-temp epoxy to prevent further deterioration.

3. Repair the spark plug hole using the proper sized helicoil. Google "Repair spark plug thread" and there are many videos and kits to choose from.

4. Replace with new head gasket and torque properly in three step process. The final torque requirement for an 89-50HP is either 225 inch-lbs or 270 inch-lbs, you need to find out which one applies to yours. Three step mean in this case we will use the 225 inch-lb final torque. Starting with the middle bolts (follow pattern provided below) and going in spiral direction, initially torque each bolt to 75 in-lb. Then start all over again and go to 150 in-lb following the spiral direction. And then the final torque of 225 in-lbs. Thereafter, go back to the starting point and double check all bolts for 225 in-lb. If a bolt turns more than 1/8 of a turn, you will continue to re-check all bolts again following the spiral direction until no bolts turn more than 1/8 turn at 225 in-lb.

Put everything back and do a compression test again. You should at least get into the 110's if not more. If satisfactory, do an op-test. But after running the engine for the first 1 hour, you will need to re-torque the head again. It is critical you re-torque.

The picture below is for a 125HP head but the sequence for your 50HP should be the same albeit lesser number of bolts. The starting point is #1 marked with a blue spot and then just follow the arrows and you will have a spiral direction.

 

[pnwboat]

Re: 89 Force 50HP turns on and stays on only on high idle start

Sent you a PM Eddie.

+1 what Jigzz says.....Looks like it's only firing one plug. Both plugs should have some carbon on them. Clean plug can be an indication that it's not firing.

 

[MickLovin]

Re: 89 Force 50HP turns on and stays on only on high idle start

If you are going to use something to repair the spark plug hole I would be using an insert, they are the best to use for this, heli-coils will have a tendancy to come out after a while of changing plugs in and out, or so that's what my engineer mate has told me.
Hey Jiggz sorry to be lazy but where is that spark plug hole repair sticky, could you give me a link you know I am old :facepalm:

 

[Eddie Rivera]

Re: 89 Force 50HP turns on and stays on only on high idle start

Wow!! Thank you so much for your feedback guys. Jiggz you are impressive!!

So you approve of my original plan of action? I thank you for including such details it's exactly what I need and love to hear. When you say clean the top of the head you mean the surface where the gasket contacts the plate and the cylinder correct? What about the passages? Should I do both spark plug holes?

There is a shop nearby where the guy is super out of this world expensive and he is mercury and force certified - he told me not to do a helicoil cuz it will not hold - and will eventually blow it out. But you are saying I could do it huh?

I bought a helicoil today for my size spark plug at Pep Boys and it's an oem fix a thred - thread repair system and also some permatex ultra copper high temp rtv silicone upto 700 degrees F. Handles oil and gasoline. I will include the picture.
So I should let it sit for a 24 hr period to be sure. Put back the new gasket I will order and then I should test correct?
Compression and spark. I understand the torque sequence how ever I want to ask how can I torque the lower bolts since I have so little space for the torque rachet??
Please advice. I'm for ever thankfull to everyone's for their input. May you all be blessed greatly for your time in helping this little me.

 

[Eddie Rivera]

Re: 89 Force 50HP turns on and stays on only on high idle start

 

[Eddie Rivera]

Re: 89 Force 50HP turns on and stays on only on high idle start

Micklovin - I thought they were all called helicoils but I saw the others with a little pig tail to insert and brakes off but this is different. Take a look at the actual items. The insert has threading inside and out - in the inside there is a little bit with no threading but on the outside there is 2/3 threading and las 3rd is knurled. So this is apparently different than a regular helicoil.

 

[Eddie Rivera]

Re: 89 Force 50HP turns on and stays on only on high idle start

 

[MickLovin]

Re: 89 Force 50HP turns on and stays on only on high idle start

Hi Eddie yea that second picture you posted looks to me like an insert, a heli-coil is normally just that a coil of hardened metal in the shape of a coil which inserts into your old thread. The one you show second, can't quite tell from the first pic, but the second one is an insert.
Don't know about using copper silicone, wouldn't think it would react with your alloy, unsure about the silicone, others would know.
No expert here btw just trying to help with what I have already come across with my outboards.

 

[MickLovin]

Re: 89 Force 50HP turns on and stays on only on high idle start

Actually put my glasses on and yes the top is an insert as well.:facepalm: