1990 force 120hp outboard HELP!

[jerryjerry05]

New marine battery???
Deep cycle???
Don't use a deep cycle.
They will work but your charging system isn't designed to charge them.
Can cause problems after a while.


Spinning starter: battery hooked up backwards?? (been done a lot)(my very first boat )
The Bendix on the top of the starter might need grease?
Lift it up and clean the screw threads with a wire brush.
Then lightly grease the threads.
Too much grease/oil can cause the rubber in the Bendix to fail.

I might have a rectifier?? let me look.
Send me a pm with your address.

Now that it's running? clean the carbs, clean the recirculation system.
Then a can of starting fluid, while running, spray around the intake side of the motor.
If the spray makes any difference then it 's sucking air and needs to be resealed.

 

[puffitu]

Thanks

the starter is brand new and already fired it up once before I re re did the head gasket again; this time right. Brand new marine battery. Seems like a voltage drop somewhere. I’ve sent you a pm-

 

[jerryjerry05]

Brand new starter or battery?? means nothing.
The "new" crap from china is just that "CRAP"
Seen them bad right out of the box.
Battery's too.

Do another compression test.

Replace the cables with new #4 or #2 cables.
You change the oil in the lower unit?
Sometimes they get water and it rusts bearings and they can slow the turning.
If everything else shows OK??
Drop the lower and then try turning it over.

A deep cycle will still turn the motor but not as good.
You need at least a 450CCA or better I had 800CCA's for my starting battery's.
One 800 has enough power to start any motor and can operate radios and depth finder all day,
without draining the battery.

 

[jerryjerry05]

The rectifier:
I have one.
Sent it today.

The part costs $10 and shipping about $5

Instead of paying me. I usually ask that whoever I sell these things to, spend the $15 at a local pet shelter.
Take them $15-20 worth of food or supplies.
If you don't want to do that?? then you can send me $50 and I'll get it to the shelter.
So far no-one has sent me any $$

If I'm breaking any rules about selling on here? I apologize and please remove it and we can
work it out through PM's

 

[puffitu]

Wow you’re the man!!
I will definitely do that..!
as of right now: I did buy a new started and as I said it just spins; the bendix is not engaging. I kept old starter and swapped it out and it does the same thing. Brand new marine battery(SuperStart) MCA@32degreesF =1000, not deep cycle. Cleaned pretty much all contacts and ground points. At this point I’m thinking it’s something to do with ignition switch?

 

[jerryjerry05]

ignition switch won't affect the starter or Bendix.
You sure the cables aren't backwards?

 

[puffitu]

ok
so after fumbling through the battery troth I found the culprit; a ground cable got mashed under the battery. yup, stupid...Anyways, I got it to turn over several times but just coughed and thats as far as Im getting as of now. I plan on comp test as soon as I charge up the batteries again. Feel as though making some progress...Thanks again Jerryjerry05.

 

[puffitu]

With a head hung low, and hoping im doing things right; I went and got a comp tester from harbor freight and did and got some bad test results after Ive replaced the head gasket(twice; torqued in sequence the second time). Before, the comp test revealed #1 at 85, #2 at 140, #3 at 155 and #4 at 150. NOW, Im getting 60, 60, 120,120...Plus after removing the plugs I noticed a milky/oily mucky substance on 1,2,and 3.
The engine is trying to run but coughs and backfires. I don't know what to do at this point

 

[jerryjerry05]

First, the Harbor Freight tester is part of the reason the tests are so low.
They are cheap and don't give the true results

The water on the plugs is probably from a bad gasket or the gaskets in the exhaust chest.


The 60/60 is probably the head gasket or the mating surface along with the HF tester.
The 120 is again the HF tester.
The 120 on both cyl. #3/4 shows the new gasket improved the comp on the them before they were 140 and 155
The results are even like they should be.

Remove the head and take some close up pics of the cylinder walls #1 and #2 cyl. and post them.
Turn the crank and take pics of the cyl. walls and then pics of the cyl. head.

You might need to use silicone to make sure the seal is good??
I use Black RTV

I recently sold a 225 Mercury.
The guy shows up with a new HF tester.
He hooks it up and starts taking a reading.
#1 80# #2 80#
I stop them as the comp is supposed to be 150# on all.
I get my tester and let him use it.
#1 150# same on all the others.
Take the HF tester back.

 

[puffitu]

My marine mechanic who did the second install of the head gasket used a sticky gasket sealer( he called peanut butter) which he gets from Promarine supply shop. He did the initial comp test with his tester. I did the second/last test with the HF crap tester. So you think I should just take the head off again because the readings were so low right? Or re test? I did pick up a fuel pump kit also,

 

[puffitu]

My marine mechanic who did the second install of the head gasket used a sticky gasket sealer( he called peanut butter) which he gets from Promarine supply shop. He did the initial comp test with his tester. I did the second/last test with the HF crap tester. So you think I should just take the head off again because the readings were so low right? Or re test? I did pick up a fuel pump kit also,

 

[puffitu]

Edit to the comp test results with HF tester: 1@90,2@100,3@120,4@120

 

[jerryjerry05]

Yes remove the head and take some "close up" pics of the cyl.
It's possible the rings on #1/2 have seized and the compression suffers.

If the walls are ok? then remove the port covers on the intake side.
They're the things the fuel pump is mounted on.
The #3 cyl operates the fuel pump.

The fuel pump shouldn't have anything to do with low comp.
Does the squeezie pump up firm? NO? then the diaphragm in the pump might be bad?.

Post some pics???

 

[puffitu]

[No message]

 

[jerryjerry05]

That shows a bit of wear on the cyl. wall.
Clean the head and mounting surfaces.
Turn the crank, move the flywheel and get some pics of the top cyl. walls.
Remove the port covers and check the wear on the sides of the piston " close up pics"
That's the one with the low comp.
Your my eyes and without good pics?? I'm guessing?

 

[puffitu]

[No message]

 

[jerryjerry05]

The pic shows some wear from the rings.
It also shows the mating surface isn't clean enough to mount a new gasket.
Next step is remove the port covers and check the rings and see if they still move?
You can push the piston back and forth and see how much slop is there.

 

[puffitu]

Port covers 1/2. Both piston ring sets move

 

[puffitu]

[No message]

 

[puffitu]

[No message]