1987 Force 85hp #1 cyl not firing

[Redline36]

Hello All,
I had my boat out for the first time this year and wouldn't you know it, it was not a fun trip. When I put my boat away last season it was running GREAT! I very carefully winterized everything so I would not have problems this year but that is not the case. When I fired up the motor it started right up but sounded funny and when I took off I really noticed a severe miss. I came off the water and when I got home I began troubleshooting. This is what I found: No spark on #1 cylinder, compression 100# to 110# on all cylinders, new plugs gave no change so I swapped #1 & #2 coils still no spark on #1 cylinder. I then swapped the CDI plug on #1 & #2 coils and I got spark on #1 but no spark on #2. I think I know the answer to my own question but I want to be sure since the boat ran fine when I put it away. Would it be possible for a CDI box to just go bad sitting over the winter? Could I have something else wrong? Any help would be greatly appreciated.

Thanks
MikeG

 

[tjello327]

Re: 1987 Force 85hp #1 cyl not firing

Figure out which cdi output is not working, swap cdi boxes around and use the one good output on the bad box for #3 cylinder, then use the good cdi box to run #1 & #2 cylinders. I am not sure if the cdi box can just go bad or not by sitting but you did pinpoint the problem by doing what you did. Now by swapping boxes around you should get it back going again. If you want to be safe, you may want to check DVA output voltage coming out of the stator to be sure it is not shorted out.

 

[GrindKore]

Re: 1987 Force 85hp #1 cyl not firing

Is it possible for something go wrong while engine is winterized in storage? Of course. Start with easy things first, check all connections on your terminal block to make sure they are in good shape. Also, check stator and trigger resistance and continuity. There are other basic checks that can be done in the garage to narrow down the exact culprit.

 

[Redline36]

Re: 1987 Force 85hp #1 cyl not firing

I went back out and swapped the CDI boxes and I got the same result. Still no spark on #1. I am going to dive into more testing.

MikeG

 

[chitownborn]

Re: 1987 Force 85hp #1 cyl not firing

check your trigger, those thin wires going into it have a problem with the back & forth movement and break under the insulation, check for continuity while jiggling them, mine was the no 3 cylinder good luck don

 

[tjello327]

Re: 1987 Force 85hp #1 cyl not firing

If all checks good with the trigger, you can swap around the stator outputs to see if the problem follows the swapped wires. I found out my stator was bad by doing this. The #1 cylinder wasnt firing so I swapped around my stator leads and the problem followed this move. I didnt swap anything else, just the stator. This proved that it was the stator, I bought one off of e-bay and it purrs like a kitten now. If you find that the stator is your problem, I have a spare the hasnt been on my engine but it did ohm test good. Send me an instant measage if interested. CHEEP!

 

[Redline36]

Re: 1987 Force 85hp #1 cyl not firing

Thanks guys! I ran out of daylight so I will try your suggestions tomorrow evening.

MikeG

 

[Redline36]

Re: 1987 Force 85hp #1 cyl not firing

Hey everyone,
Here is my final findings. I did remove stator and trigger for inspection as well as testing. Visual of both seem OK. I checked all pairs of trigger wires with an Ohm meter and got 47.5 to 48 Ohms on each. From my manual that seems to test fine. Now when did an Ohm test on the stator I got 800 Ohms with one pair of yellow & blue wires and I got 0 Ohms when I did the other pair. Should both pairs have the same Ohms? If so then I would say my stator is bad. Does anyone agree with my logic?

Thanks
MikeG

 

[chitownborn]

Re: 1987 Force 85hp #1 cyl not firing

you got a bad stator, I believe you should read between 600 to 800 ohms on either pair of yell & blue pairs, with a zero reading on one pair you got an open in one side of your stator, not feeding the mod any power

 

[tjello327]

Re: 1987 Force 85hp #1 cyl not firing

There should also be a resistance check that can be done also. I dont have a book in front of me but I think you are checking to be sure you have a zero reading between the stator housing (ring) and the blue wires. If it shows a reading, the stator is shorted out. Now going back to your findings, the bad reading you got on your stator, does it match up with the #1 output? If so, I think you found your problem. I swappped my stator leads around and my no spark issue followed the move which proved it was my stator, I swapped out and it worked. The stator I have at home was bought off e-bay that was removed from a blown engine. I never had it on my engine to test, it is just a back-up for the one on mine now if it didnt work. I am listing it on e-bay under e-bay motors/boats/force/motors & parts/used. My user name on e-bay is tjello327.

I hope this helps.

 

[Redline36]

Re: 1987 Force 85hp #1 cyl not firing

Hello everyone,
Well I got a used stator. I check the Ohms on it and I got one pair of wires with 700 Ohms and the other pair with zero. The pairs where opposite of the reading I got on my stator. I thought maybe I was doing something wrong so I went ahead and took the time to install the stator I just got, low and behold #1 spark plug started firing then I got to #3 spark plug and it was dead. Now I get to rip it all back apart again. Soon I will be able to wire the ignition with my eyes closed. The manual does not define that both pair should have resistance I am only assuming that, I guess my question is should both pairs of wires one yellow & one blue have resistance when I have the stator on the bench? If that is the case I will see if I can return the used one I got and just buy a new one. My frustration level is peaking but I am not ready to give up yet.

Thanks
MikeG

 

[Redline36]

Re: 1987 Force 85hp #1 cyl not firing

Well everyone, I put in a new stator and she runs like a champ!!! I would like to thank everyone for their help. This site has some of the most helpful and friendly people I have ever meet. I hope I am able to help someone someday as well.

MikeG