1990 Force 120HP #2 Cyl zero compression and upon opening piston shows damage

[Nordin]

Yes as The Force power and racerone says, what kind of batteries do you have and what are the conditions of them.
Generally the stator start to charge at about 1100-1200 rpm and the voltage you see at the gauges depends on how much the batteries are charged.
If they are a bit discharged the voltage will be lower and the stator is able to put out 9-12 Amperes at WOT and when the regulator regulate the voltage to about 15-16V.
The batteries are acting like a big accumulator in the system and will push the voltage down especially if they are not fully charged.

 

[gica]

Batteries are SuperStart Marine Deep Cycle. I almost always charge them before going out. I don't know if I did that when I took the picture. The motor was acting up so maybe I turned it a few 20 times and one went down a bit.
When I did test it at idle it was really slow to gain voltage but it did. I didn't know it starts to charge at 1100 or 1200 RPM.

 

[The Force power]

the voltage you see at the gauges depends on how much the batteries are charged.

In addition to this; Dash gauges are not the most accurate, for proper reading a reputable voltmeter should be used

 

[gica]

Ok but my question stands should the reading with a voltmeter read say from a standing 12.5 battery go up right away or really slowly. When I read it with a voltmeter it went up slowly, I mean really slowly like 1 volt at a time it didn't jump up to 13 or so.

 

[racerone]

I would say the voltage should rise right away.----It does on other motor brands.----Have you considered getting a pair of different motors.----Seems there are a lot of issues.

 

[gica]

I would say the voltage should rise right away.----It does on other motor brands.----Have you considered getting a pair of different motors.----Seems there are a lot of issues.

Actually, I am at the end of the issues, one motor is completely rebuilt top to bottom. I am ironing out the kinks now. if I were to change the motors I would probably do one 200HP motor not 2. But after all this work I don't want to take that route yet. I understand these motors inside out right now. I still ask for opinion because it a better choice to hear others with experience.

 

[topgun3690]

Batteries are SuperStart Marine Deep Cycle.

Install a marine starting battery and see if the charging rate changes.....

 

[gica]

I was wondering I can fit 2 batteries on one side and only one on the other. I have 2 Lowrances lives 9 inch, 3 night lights, 3 transducers, at least 3 pumps for bait and bilge and stuff. Can I just buy a 1k cca starting for both engines? Found one 27M at Pep Boys for 140. I think I saw the 24M 500 or 600 CCA for 80 or so.
Nevermind bad idea 2 engines charging same battery not good.

 

[gica]

Ok so I bought the 800 cca starting battery and installed it next to the deep cycle one. I plan to install a switch: Off, 1, 2 and All.
So my question is can the stator for the 120 charge 2 batteries, is it strong enough?
I am gonna do the same on the other side for the other engine.
I mean I can just charge the deep cycles at home and use position 1 on the switch if beed be.
Let me know and thanks.

 

[The Force power]

Ok so I bought the 800 cca starting battery and installed it next to the deep cycle one. I plan to install a switch: Off, 1, 2 and All.
So my question is can the stator for the 120 charge 2 batteries, is it strong enough?
I am gonna do the same on the other side for the other engine.
I mean I can just charge the deep cycles at home and use position 1 on the switch if need be.
Let me know and thanks.

In my opinion.....the most important thing to have is a voltage-regulator.
Either built-in with the rectifier Or hooked to the stator.
You want to keep the voltage at bay (14.5 max) to protect your electronics.

"So my question is can the stator for the 120 charge 2 batteries, is it strong enough?"
This all depends on how long the engine is running & at what RPM

 

[gica]

The rectifiers are the enclosed square ones with wires not the older rectangular ones with poles. I have no clue if they have a regulator built in.

 

[The Force power]

The rectifiers are the enclosed square ones with wires not the older rectangular ones with poles. I have no clue if they have a regulator built in.

Run the engine with the positive wire from the rectifier disconnected (leading to the battery) check if the voltage creeps up to around 16 to 19+ volt at the positive terminal from the rectifier. IF it does? its just a rectifier

 

[gica]

Dropbox

www.dropbox.com

In the link there are 3 videos on at idle second in gear at higher rpm, third pretty much same. In the first one you can clearly hear and see the issue. Sometimes I heard a little choking.
I am trying to figure out how to get rid of the stutter, at idle and less obvious at higher RPM.
I fished the wiring and I do have good idle now. But the stutter is pretty stron at idle.
It is not continuousbut it is obvious. I don't know if it is carb adjustment or cleaning or electric problem including coil.
Need advice thanks.

 

[The Force power]

You probably went thought / checked this already;
NO FIRE OR INTERMITTENT ON ONE CYLINDER:

1. Check stator and trigger resistance, trigger wire sets read approximately 50 ohms between the wire sets (DVA-4V or more), stator reads 680-800 ohms (factory) and 200- 300 (CDI/RAPAIR) DVA 180V or more from blue to yellow.
2. If readings are good, disconnect kill wire from one pack. If the dead cylinder starts firing, the problem is likely the blocking diode in the other pack.
3. HIGH SPEED MISS:
   1. DVA check stator voltage to each pack at high speed. If it exceeds 400 volts, replace the pack.
   2. Disconnect the rectifier. If the engine fires, replace the rectifier.

 

[gica]

OkForce Power, so I don't know if I am doing it right but I measured resistance between all the 4s, 3s,2s and 1s. I fillmed it all. Between the 1s I get 55ohms and between the last 2 and first 1 I get OL. The rest are 51 or 52. The other motor shows 51 or 52 also.
Mostly 51 ohms.
So between tye 2 wires that have 1s on them I get 55ohms. But from any other one to the 2/1s I get OL
Also from any of the firsts 4,3 and 2 to tye mounting screw I get 52s and from the second 4,3,2 wires to tye same bolt on tye picture below I get 0. But from the 2 wires to the same bolt I get nothing.
Gor tye stator I get 576 between 4 and 3 and 717 between 2 and 1
Again don't know if it's what you suggested. Let me know and thanks.

Dropbox

www.dropbox.com

 

[gica]

Anybody?

 

[The Force power]

Anybody?

I'm struggling with these issues myself & for myself to simplify this;
I disconnected ALL the trigger-wires from the terminal-bar to eliminate any false readings & clarity
(1) verify you're taking a reading from the correct trigger-wires (per set)
Then disconnect all the Stator-wires (except the two for the rectifier)
(1) Make sure you're taking the readings from the correct wires (per set)
by checking if indeed the two wires are in the group of coils on the stator
(2) The set that was reading 576 Ohms check the the wire-terminals by bending & pulling on it to see if the wire is actually properly secured

Hook everything back up & check the voltage-output on each set of trigger-wires & Stator-wires

 

[The Force power]

No readings are taken from the trigger-wires to ground only between the sets (#1/#2/#3/#4)
With all the wires still disconnected; take a volt-reading(with a DVA-adapter attached to your meter & meter set to DC volts)
(1) from each set of trigger-wires = should around 4.5 volts
(2) from each set of Stator-wires = should be around 180 volts

IF no DVA-adapter hooked-up to meter; set meter to AC volts & data-hold

all voltage-reading (test) is by cranking-speed

 

[gica]

Ok
But the trigger wires have to sets each one is ground

 

[The Force power]

But the trigger wires have to sets each one is ground

Where do you see any of the trigger-wires going to ground?