1986 85HP ignition problems (not firing in the right order)

Randal106

Seaman
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Jun 24, 2006
Messages
56
Ok i have a 1986 85 HP Force, Prestolight Ignition.

when i try to start it, it will not start, but kind-of backfire/ kick-back. if i pull the #2 plug wire, it will crank right up and run fine on the #1 and #3 cylinders.

according to all the diagrams i have, the stator is wired up fine. i even swapped the CDI boxes around and the same thing happens.

Any Ideas??

THANKS
 

Frank Acampora

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Jan 19, 2007
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12,004
Re: 1986 85HP ignition problems (not firing in the right order)

That's really quite knotty-- It's been a long time since I opened one up but Prestolite has quick connects. So, the stator and triggers must be correct. -- unless the trigger quick connects were forced together. However, if you have reversed the 1 and 2 coils on the CD box or on the plugs, it could cause your problem. The stator only supplies power to the boxes and does not have anything to do with the timing of the spark.

3 is by itself in the second box and would be unaffected. 1 and 2 each come from a different side of the first box

Firing order is 123, top to bottom and they are 120 degrees apart. Coils are also 123 top to bottom. So: first be sure that the plug wires are connected this way. Then, if correct, check the coil to CD box connections. if the 1 and 2 were reversed, then 3 would fire at the proper time, 1 would fire 120 degrees late and not have too much effect, but 2 would fire 120 degrees early and backfire.

#2 coil should be connected to the white wire on the CD box--I forget what color the #1 wire is. If #2 is not connected to the white or if the colors are for some reason different, try reversing the coil connections on the first CD box.
 

Randal106

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Re: 1986 85HP ignition problems (not firing in the right order)

Thanks Frank. ill give that a shot tommorow, and double-check everything.

mine does not have the quick-connects, only the coil to cd-box has connectors, the rest are on a terminal strip. so let me get this correct though, the stator ( round with the copper wire coils) supplys a constant power to the CD-Box's and the triger (has two blue and two yellow wires coming from it, under the stator) tells the box's when to fire?? is that correct??
 

Frank Acampora

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Jan 19, 2007
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12,004
Re: 1986 85HP ignition problems (not firing in the right order)

NO. Blue and yellow are power to CD boxes. Since it is 3 cyl, the two blue are connected together on the same terminal. The two yellow are on separate terminals. Then there are six thin multi colored wires (three pairs--I forget the colors though) coming out from under the flywheel. These are the trigger wires and must connect to the proper terminals. You MAY have a wiring diagram on the block--if so it will tell you wires and position. If not, Tomorrow I will go down and look at my 90, and tell you the proper colors and position.
 

Frank Acampora

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Re: 1986 85HP ignition problems (not firing in the right order)

OK! Here you go: From the front of the terminal board progressing toward the rear, the wires should be connected like this

1. White and yellow from the CD box connected to white/brown/yellow from the trigger
2. White and orange connected to White/brown/orange
3. White and red connected to white/brown/red
4. White and green connected to white/brown/green
5. White and yellow connected to white/black/yellow
6. White and orange connected to white/black/orange

1 through 4 should be the first box firing #1 and #2 cylinders, 5 and 6 service one side of the second box firing #3 cylinder

If for some reason, one half of a box fails, the two CD boxes can be rewired to use the currently unused half of the #3 box and save a couple of bucks.
 

Randal106

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Jun 24, 2006
Messages
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Re: 1986 85HP ignition problems (not firing in the right order)

Thanks for the help, but i have none of those wire colors coming from under the flywheel on mine LOL. i have 2 orange, 2 green, and a green/white?? (may be red/white) and a red
 

Frank Acampora

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Re: 1986 85HP ignition problems (not firing in the right order)

Dang! You have me confused--my diagrams show Prestolite as quick connects yet you say you have a terminal board. Yet you also describe the colors for a Prestolite system. I'll bet sombody retrofit it with a terminal board

OK--I have the trigger assembly in my hand. White with a green stripe, and also red goes to the #3 side of the second CD box. Then, both #1 and #2 have a green and an orange wire. That's where the confusion must be. SO try switching the green and orange from one side of the CD box to the other side. Since the coils also have quick connects, It is possible that the coil leads were reversed. So before you start switching wires, take off the three retaining nuts and pull out the CD and coil mounting plate. See if the red lead out of the side of the CD box connects to the #1 coil, and the orange connects to the #2 cylinder.

See: the original Prestolite had quick connect fittings so the wires for #1 and #2 cylinders were the same green and orange color pairs. It didn't matter because with the quick connect there was no way to reverse them.

Now after all this, it is possible to wire the whole system in different ways, such as the first box firing only #1 and the second box firing #2 and #3. It is also possible to wire it in reverse so that orange powers the top coil and red powers the bottom. Without being there and actually seeing and touching it is almost impossible to determine if your wiring is correct. You really need to study what you have. With these hints, Assuming you have the Prestolite colors, you should be able to figure out what you have and how it should be. Pick a CD box. Call it the first one. A blue, a red, and a green and white wire go into the top and a green, a yellow, and an orange go into the bottom. Top powers the red wire on the side and this fires coil#1. bottom powers the orange on the side and this fires coil#2. The other box is the same and the yellow set on the bottom powers the orange wire on the side which fires coil#3.

Bet your head is spinning now! LOL.
 

Randal106

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Jun 24, 2006
Messages
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Re: 1986 85HP ignition problems (not firing in the right order)

Hmm. i was re-reading your first post, could it be possible that the #1 and #2Cylinders are firing backwards, AKA.... it would still run on #3 firing correctly and #1 plug being fired when #2 should be. making it fire a litte late, but still on the down/power stroke of the #1 cylinder?? so all i would have to do is swap the quick-connects on the #1 & #2 CDI box correct???

Make sense LOL?????

i will be able to get some time to work on it this evening after work.
 

Frank Acampora

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12,004
Re: 1986 85HP ignition problems (not firing in the right order)

That's pretty much what I said the first time. You have the option of switching the wires signaling the CD box or going behind and switching the quick connects to the coils.
 

Randal106

Seaman
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Jun 24, 2006
Messages
56
Re: 1986 85HP ignition problems (not firing in the right order)

Ok, got it running.

white w/ green and red on #3

orange and green on #1 and #2

the wiring diagram i had on the motor had #2 as white w/ green and red

and #1 and #3 with orange and green.

That is where all the confusion was. I want to thank you Frank, as i can now go do some fishing after i get the fuel pump replaced (Surges at WOT)

Seriously, i need to send you some money or something LOL
 

uthibwc

Recruit
Joined
Apr 30, 2022
Messages
2
Ok i have a 1986 85 HP Force, Prestolight Ignition.

when i try to start it, it will not start, but kind-of backfire/ kick-back. if i pull the #2 plug wire, it will crank right up and run fine on the #1 and #3 cylinders.

according to all the diagrams i have, the stator is wired up fine. i even swapped the CDI boxes around and the same thing happens.

Any Ideas??

THANKS

Re: 1986 85HP ignition problems (not firing in the right order)

Ok, got it running.

white w/ green and red on #3

orange and green on #1 and #2

the wiring diagram i had on the motor had #2 as white w/ green and red

and #1 and #3 with orange and green.

That is where all the confusion was. I want to thank you Frank, as i can now go do some fishing after i get the fuel pump replaced (Surges at WOT)

Seriously, i need to send you some money or something LOL
please excuse my writing French is my first laguage.
FOR 1986 85 HP Force, Prestolight Ignition.
Hi all, i have use this forum so many times but this is my first time writing and i m not sure i should use this 14 year old post but it is exactly my probleme. here is my story i bought this force 85hp 1986 and all the quick connect wire were cut and replaced with home made connectors. i did step by step the manual test and endded up changing the 2 cdi one was completely dead and the other i didnt have the recommanded 210v output to coil. my probleme now is... i have these 2 sets of green and orange and a red and white from the trigger. my shop manual (HAYNES) refert to these colors (where to connect them to cdi) without mentionning wich ones of these green and orange are for cyl no 1. it makes sense beheing that if i had the quick connect i wouldnt have to ask it would be impossible to reverse them.
i HAVE on the trigger from the adjusting arm going clockwise
adjusting arm --> green+orange --> red+white --> green and orange

CAn someone tell me wich green-orange is cyl no 1 ?? wich one do i use to send to cdi and then to coil ?
 

jerryjerry05

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May 7, 2008
Messages
18,075
I'd do a compression test before doing anything else???
I believe the solid Green/ Orange is #1
The stripe leads are #2
I think.
 

uthibwc

Recruit
Joined
Apr 30, 2022
Messages
2
I'd do a compression test before doing anything else???
I believe the solid Green/ Orange is #1
The stripe leads are #2
I think.
Thak you for replying.... i did this before buying any parts it was 110-115-110..
My probleme is solve... actually the answer was in this post... when randal said:
Ok, got it running.

white w/ green and red on #3

orange and green on #1 and #2

the wiring diagram i had on the motor had #2 as white w/ green and red

and #1 and #3 with orange and green
Same for me all wiring diagram i had gave me the wrong #2 (red white/green ) is actualy #3
I beleive red-white as #3 is ONLY for 1986 prestolite L drive
I hope this can help someone else
 
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