1989 Force 125hp ignition help /idles great-no power

[xjskins]

I have a new to me 1989 Force 125hp. I have had it out once and all seemed well until the float bowl fell off. I have fixed that, now the darn thing will not run right.

I believe it to be an ignition problem.

Symptoms:
-Once in gear (under load if you will) the engine has great difficulty in increasing RPM and thus accelerating the boat.
-It does not reach max RPM, (no tach) but I would guess 2500-3000 RPM tops
-I assess that it has greater than normal vibrations
-I can remove the coil wire from 1,2, and 3 without stalling the engine. If i remove 4, the engine immediately dies.

I have:
-Complete cleaning of carbs
-new fuel lines
-completed the link and sync as per this forum direction. I pulled plugs and ground coils to set timing at 28 deg WOT at cranking speed. RPM were set by feel, slightly above stalling when shifted into gear.
-clear fuel filter prior to carbs. (always a decent amount of fuel available)
-fresh gas at 50:1
-new marine battery (non agm) (charged with charger prior to each testing)
-Compression test is 140-145 on all cylinders

SO, what next?

Should I set timing at 30 deg WOT on the water even if the engine is not running good?
Should I learn about DVA readings and follow instructions? who has the best instructions to follow?
What should I be looking at first?

It the long weekend and I want to go boating.....Thank you to all those that can help

Cheers
Rick

 

[Jiggz]

You have good compression so the next step is to validate you have sparks on all cylinders and not misfiring. If you have sparks on all cylinders then the next step is to make sure fuel gets into the cylinder and that the throttles do open with the control lever. double check the fuel air mixture screw is set to 1 - 1 1/4 turn out from lightly seated. I have mine at 1 1/4 turn out.

Do not confuse the choke throttles located at the mouth of the carbs with the throttles located at the back or throat of each carb. After this the next step is to run the motor on muffs. Using the tie bar rev up the motor and it should respond smoothly and quickly.

 

[xjskins]

I will confirm spark tomorrow morning.

Throttles open equally and horizontally. Mixture screws set at about 1 1/4.

When using the tie bar (in neutral) the engine revs up as one would expect, smooth and snappy.

So, I was grasping at straws and disconnected the rectifier, insulating the stator leads. It was troublesome to start, but once started, accelerated (in gear) as nice as one could test while tied up to the dock. I then did a diode test and it checked out, however the ohm rating was out of spec. I will order a new rectifier and conduct an open water test (after confirming spark).

Thanks Jiggz for giving me something to focus on.

Does this new info on the rectifier change any probable diagnosis?

Thank you forum

 

[Jiggz]

The rectifier can affect the stator power to the CDM's. There are two circuits (ckt) in the stator. One for the charging ckt (green/yellow wires) and the other I refer to as power ckt as it directly powers the CDM's (yellow and blue wires). If the rectifier is faulty it can affect the power ckt causing intermittent misfiring. Hence if you disconnect the rectifier it'll run smoother.

You can test if the rectifier is faulty by doing voltage testing. With engine off read battery terminal voltage. Start engine and place it in fast idle to about 1500~2000 RPM. Read voltage across the rectifier input and it should read around 16~20 volts AC. Then switch to DC voltage and read rectifier's output and it should be above 13.5 volts DC (or at least higher than the battery terminal voltage taken earlier). Just make sure all accessories are in off position. If your readings are in this ball park the rectifier is good. If not then it is faulty.

I've replaced my rectifier with a Radioshack rectifier for less than $5. They got them at the bidding store also. The rated voltage should be 12V with an ampere rating of 25 amps. Minimum should be around 10~12 amps. Even though the stator charging ckt is only rated at 7 amps.

 

[Jiggz]

I'm quite sure you are well aware of this starting procedure: But I'll re-iterate just to make sure:
1. Ensure motor is in full vertical
2. Depress the primer bulb until it gets firm (usually 4~5 times)
3. Place control lever in fast idle position. Depending on style this means pressing a center button and pushing the lever forward or like in my case pulling the lever straight out (towards driver or towards port side) and pushing it forward. It doesn't have to be all the way forward. You'll have to experiment how much it takes for easier starting.
4. Press down on the ignition switch to activate the choke (you should hear it click, if not choke is not working)
5. While pressing down on ignition switch, turn to on and finally to start position. And the starter should crank over the engine.
6. Continue to crank until either it starts, or "coughs" (disengages the starter if it does this) or no more than 5~7 secs at a time.
7. If it "coughs" reset ignition switch to off.
8. Restart again but this time without choking, i.e. just turn ignition switch to on and then to start.
9. If it would not still run or fire after two additional tries, Try again starting back to step #4. DO NOT OVER CHOKE AS IT WILL EASILY FLOODS AND MAKES IT VERY HARD TO GET IT STARTED.
10. As soon as the engine starts, let it warm up for about 30~60 seconds before placing the control lever back to neutral.
11. Idle speed in neutral should be around 1000~1200 RPM depending on the size of the prop. Idle speed in gear should be around 700~800 RPM, again depending on the size of the prop.