90 HP force ignition help

[A.Hoj]

Hey guys, Was on here last summer trying to figure out whats wrong with this motor and never got to the bottom of it before winter, now I'm back at it again.

1998 90 HP Force

Motor dies/boggs down under heavy load/rough seas or high Rmps

Its not a fuel issue, I have been through the fuel system 100% and I'm sure thats not the problem.
also, it has a new head gasket and exhaust gasket.

Today I tested the stator and when I touch the two green/white wires I get 220 Ohms. The book calls for 500-600 Ohms.

Also I noticed that one of the yellow wires coming from the stator is burnt at the connector some. (see picture)


My question is, would a bad stator give me this reading? is there another way to test it before i go out looking for a new one?

Thanks
Andrew

 

[bentle]

Re: 90 HP force ignition help

For sure. I would go through all wires and find the either bad ground or wire shorting out. You only see melting like that for thoughs reasons. This may be the reason your stater is reading so high. As far as the bogging is there a possibility that the fuel vent hose is getting full of fuel or water and not allowing the tank to vent properly? This can happen if the vent hose sags lower than the tank.

 

[A.Hoj]

Re: 90 HP force ignition help

Ill check the wiring all around the best I can, I dont want to fry another stator if I end up replacing it.

As far as the bogging is there a possibility that the fuel vent hose is getting full of fuel or water and not allowing the tank to vent properly? This can happen if the vent hose sags lower than the tank.

I have two new aluminum fuel tanks, and a protable tank and it does the same thing with all three tanks. I removed the tanks last winter and cleaned them thoroughly and double checked all vents and lines and they are good.

 

[bentle]

Re: 90 HP force ignition help

If you don't mind could you list all the fuel related items you have done. Also anything done to the motor. This will help us out a bunch, so we're not telling you to fix something you may have already done.

 

[A.Hoj]

Re: 90 HP force ignition help

so far I have

-Cleaned & Rebuilt all three carbs
-Cleaned fuel tanks/added new fuel 50:1
-New fuel lines and Primer bulb
-New water seperator and fuel filter
-rebuilt fuel pump
-Installed clear fuel lines to check for air bubbles
-Inspected and cleaned fuel recirculation ports
-Inspected reed valve assy.
-new head gasket and exhaust gasket
-New plugs
-Checked timming (good)
-Did the link and sync, several times
-Adjusted the idle mixture several times.

I was sure it was a fuel problem for a while, but after going over these things and reading a lot of similar problems on other motors I realized it's most likely an electrical problem. I don't have the Test harness to test the CDMs yet so I started checking the ingition system with the stator and I'm hoping this is the problem. I would also like the test the CDMs and the voltage regulator to make sure they are ok too.

 

[riptorn]

Re: 90 HP force ignition help

What kind of plugs are you using?

 

[bentle]

Re: 90 HP force ignition help

If your not getting good spark to all cylinders then same things can happen. This could be related to the stater problem to and that burned wire. Oh the stress of it all anyways.
Im pretty sure there is a short somewhere so I hope you can find the little bugger and solve the problem.

 

[pnwboat]

Re: 90 HP force ignition help

200 ohms would indicate that the some of the windings in the stator have shorted together decreasing the over all resistance and probably lowering the stator output voltage to the CDM's. Your stator is bad.

Those burnt yellow wires are the stator output to the voltage regulator. Very common to see that. Even on motors that are working just fine. Not sure why that is but I suspect that the "bullet" connectors are not heavy enough to handle the current. I got rid of the bullet connectors on the yellow wires and used a terminal block with screws. Replaced the bullet connectors with spade lugs and so far have not seen any evidence of over heating on the yellow wires. See the terminal strip highlighted by the yellow box.

 

[A.Hoj]

Re: 90 HP force ignition help

riptorn---the plugs are Champion L76V

Bentle--- I haven't checked the spark with a good spark tester yet but I will next week.

Pnwboat-- thanks for the tip on the termial block I'll probably do the same thing when I get the new stator.


Any suggestions on where to get a stator? I've found a few used ones for a lot less than the price of a brand new one. And also is there a way to make a test haness for the CDMs or is that something you have to buy new?

Thanks

 

[riptorn]

Re: 90 HP force ignition help

Might try using a different brand of plugs. I have NGK in my 1988 85hp Force.
Just a shot in the dark but worth a try.

 

[pnwboat]

Re: 90 HP force ignition help

I've had good luck (knock on wood) with buying the used Red stators on line. Not 100% sure but it looks like they used the same stator from 1996 - 1999 on the 40HP - 120HP motors with the CDM ignition. Looks like CDI makes two replacement stators for those motors. One has a 9amp battery charge coil, the other is 16amp. If your voltage regulator has "5279" in the part number, you can use the 16amp version.

Not sure about a test harness for the CDM's but there are some resistance readings you can check on the male pins on the CDM where the harness plug goes. Pretty common to get used CDM's for about $25. Brand new they're about $65.

 

[florida blue water]

Re: 90 HP force ignition help

repair the burnt connection. with a quality solder job because that is a loss of voltage threw that connection. nothing will work right with low voltage.

Hey guys, Was on here last summer trying to figure out whats wrong with this motor and never got to the bottom of it before winter, now I'm back at it again.

1998 90 HP Force

Motor dies/boggs down under heavy load/rough seas or high Rmps

Its not a fuel issue, I have been through the fuel system 100% and I'm sure thats not the problem.
also, it has a new head gasket and exhaust gasket.

Today I tested the stator and when I touch the two green/white wires I get 220 Ohms. The book calls for 500-600 Ohms.

Also I noticed that one of the yellow wires coming from the stator is burnt at the connector some. (see picture)
View attachment 137860

My question is, would a bad stator give me this reading? is there another way to test it before i go out looking for a new one?

Thanks
Andrew

 

[A.Hoj]

Re: 90 HP force ignition help

Thanks , I'll get the connections taken care of.

Turns out the stator is fine, Had a friend come over with a better Multi-meter and double check my readings. This time we got 650 Ohms..so on to the next step.

I stil haven't rules out the fuel/carbs I'm just not sure what I could be missing. is there a chance that air is getting sucked in through the recirculation hoses?

 

[pnwboat]

Re: 90 HP force ignition help

Looks like you've covered all the most common problems. If it boggs down under rough seas, that sure sounds like a carburetor float adjustment. Does the primer bulb get good and firm when you squeeze it 4 or 5 times? Is the fuel tank vent open?

One other thing to check is the Fuel Enrichment solenoid. Sometimes they will stick open dumping too much fuel into the motor. You can check by clamping off the fuel supply line to the Enrichment solenoid from the top carb fuel bowl.

 

[A.Hoj]

Re: 90 HP force ignition help

The primer bulb gets firm and stays firm even when the problem occurs. I have twin 19 Gal. aluminum tanks with permenant vents that don't close.

I will check the fuel enrichment valve next(again). As soon as we get some decent weather I plan to go out with a friend and try some adjustments on the water and see if it helps. Its possible that I just dont have the idle screws set right.

In my factory service manual it says to seat the idle screws lightly then back them out 1 full turn, then turn them in 1/8 at a time until it "pops", then back out 3/16. is this correct? Or should I turn them out farther before start the process?

 

[pnwboat]

Re: 90 HP force ignition help

Usually somewhere between 1 to 1 1/2 out from lightly seated is where most motors run best but it varies from each individual motor to motor. Just don't go any leaner than 7/8 out from lightly seated. I would set it for 1 turn out and see how it acts. If it still doesn't like that try going out 1/8 of turn and test. If still no good try turning it out another 1/8 turn etc.

 

[A.Hoj]

Re: 90 HP force ignition help (Fixed!)

Re: 90 HP force ignition help (Fixed!)

Fist off thanks for the help and suggestions. I guess I should have listened to everyone about the fuel system becuase thats most likely the cause in one way or another.

Took the boat for a ride yesterday and ran at WOT for a few minutes several different times with no problems. I'm still not sure it wont happen in the future but its a start!. I'm not even sure what I did to fixed the issues but here is what I did most recently.

Fixed burnt wire connections
Re adjusted timming
Link & sync the carbs
Adjusted carbs in water with motor running instead of on the hose
New fuel filter, and some new hoses after the fuel pump with stainless clamps not wire ties.
Mixed up some fresh fuel in the protable tank with the new primer bulb.


Next i'll get out fishing and test it in a more realistic situation.

Thanks again
-Andrew