85HP Force Outboard Acceleration/Speed

Horse4190

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Need help for my 89 Bayliner Capri with 85HP Force Outboard. Speed is only about 10 miles when switching to forward and no much acceleration. I have changed with the new spark plugs. Gas was from last year with stabilizer and cycle oil and added only about 1 ltr few weeks ago. Do you all think I should replace the gas with the premium/special gasoline? Thanks
 

Nordin

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As it only run 10 mile it seems it is not runing on all cylinders.
Check for spark at all plugs and then check the compression.

These 3 cylinder engines are strong enough to run on only 2 cylinders and if they fail at one of these thing you only get about 8-10 miles
 

Horse4190

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Thanks Nordin. I will check the sparks and perform compression test this weekend. If the sparks and test are okay, what do you think the other options or issues?
 

jerryjerry05

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More info??
Does the motor rev up as you throttle up? and just doesn't go?
Miss or backfire?
Check the plugs for even burn?

Don't run premium, not good for your outboard.

Prop in good shape?
One guy with a prop in worse condition was wondering why his motor wouldn't run right?? :)

More info??

Image result for pictures of bent propellers
 

Horse4190

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Thanks Jerry. I am about the replace the gas to premium this weekend and good that you told this. Thanks again. Yes the motor will reverse when I throttle up.
As I am going to check the plugs and also the compression test, when I perform the compression I assume I will only remove the plugs and nothing else - is that correct?
 

Nordin

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When perform the compression test you have to have the HT wires at the plugs and ground the plugs too.
If not grounding the plugs you can damage the CDI boxes because the CDI boxes have to dump the charged voltage in the capacitors.

If you have a lanyard, pull it then you do not have to worry about the voltage in the CDI boxes.
 

jerryjerry05

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If you use the key, you need to ground the plug wires.
You can still do damage to the packs if the wires aren't grounded.
I disagree with Nordin on that.

Even pulling the lanyard isn't safe for the packs.
I did it that way when I was a newbie, my boss chewed me out saying it could still hurt the packs.
My boss knew EVERYTHING about Chryslers and Forces

Using the key you need to ground the plug wires.
 

Nordin

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jerryjerry my experience about pulling the lanyard is that it would be enough to prevent damage the CDI boxes.

But you are a pro OB mechanic and I am just a leisure mechanic so I believe you.
Thank you for the information, from now I will ground the plugs when performing compression test.
 

Horse4190

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Sorry again for the next question as you know I am not a technical person and new to this. When grounding the plugs to perform compression test using a key in the cockpit to crank the motor, can I clip the one end of the wire to the spark plug and the other end of the wire to the ground or to any metal part of the boat? Can I also use a jumper cable in the car for grounding the plugs?
 

Nordin

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Horse4190 when grounding the plugs you pull the plugs but have them connected to the HT wires and then you have to have contact between the plugs and ground by for example holding the plug thread against the block when cranking.
This allow the CDI boxes to spark the plugs/(dump) the voltage in the capacitors which is in the CDI boxes.


You can wrap steel wire around all plugs and then around some place with good ground at the block.
I have made a tool of a copper bar where I have drilled 6 holes (to manage a 6 cylinder engine) and threaded the holes for plugs (M14x1,25).
At the end of the bar I have connected a wire with a clamp to hook at the block for good ground.
 

jerryjerry05

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I took a #2 electrical cable/wire end, cut 3 #10 pieces of wire about 16" long.
Stripped the ends.and made a 3 wire octopus for grounding the wires.

I had a pic on here but it's been years since I could use the pics as the site won't let me access my photos :(
 

Horse4190

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I've done my compression test and still looks good 120psi for each 3. My problem is the spark plug tests. All the 3 have no sparks but all the spark plugs are brand new. I used the 3 plugs tester. Do you think the problem are the HT wires or coils?
 

Nordin

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Well then you have a problem in the ignition system.
Check which cylinder that do not have any spark.

As you have a Force 85Hp 1989 I suppose you have the Prestolite system with 2 CDI boxes.
Each CDI has 2 output channels and box #1 manage cyl. #1 and #2. Box #2 manage cyl. #3 and then it has one untapped output channel.

Start to check which cylinder that fails and report, then wel will help you to to some troubleshooting or go to CDI Electronics web site.
They have a troubleshooting chart for that ignition system.
 
Last edited:

jerryjerry05

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New plugs means nothing!!
Coils: in 35+ years I've only seen 1 bad coil, all 3 bad at once?? not very likely.

No spark on all 3 could be the safety lanyard, the stator, the rectifier, a bad ground and few others.

The first thing I'd test is the stator.
outbooardignition.com has test procedures for your motor.
 

Horse4190

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I want to try first if the coils are bad. Can you let me know how to test the coils using multimeter - the possitive (red wire) will go at where? I wish i can upload the picture but exceeds the limit. Thanks
 

Nordin

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The factory manual does not give spec. for resistance of the coil prime or secondary side but 200-600 Ohm would be about right.
OMC has about 200-250 Ohm at secondary side and older Chrysler with Magna Power CDI system has 500-600 Ohm.
Prime side should be about 0,5-1,5 Ohm.

The factory manual says 210V DVA or more as output from CD box to the coil.
Or check with a spark tester, the coil should jump a gap of 7/16 of an inch in atomsphere.
 

jerryjerry05

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To add pics, either resize or use a photo sharing site, Shutterfly or something similar.

Testing the coils.
Spark testers and install on all 3 cyl.
Then turn the motor over.

Outboardignitiondotcom. do the stator test.
No spark on 1 could be the coil.
No spark on 3 is probably the stator.
It can also be the tach or regulator is bad.
Loose ground, loose connections??
 

Horse4190

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Hi Jerry, I've tested the coils using the testers and no sparks. I will also test the Stator, but before testing this I have one of the coils taken out from the motor and wanted to test by multimeter. Attached is a .pdf version of the coil and need help which wires of the multimer goes to? Thanks for your help. View attachment Coil 85HP.pdf
 

jerryjerry05

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Unless you can apply a load??
Then about the only way to test a coil is to swap it with another.
 
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