91 Force 70hp "free" starting issues

[CaptnTony]

I was given this motor by a friend of the family who took it off a pontoon boat. I did not receive any controls with it, but. I'm hoping it moves to my fishing boat once I get it running. I was told that it ran the last time they used it (of course..who uses it when it isn't running). It had been sitting indoors since 2015 though, never seeing the water. I'm not an engine person, but I'm willing to try and learn as I go. I took cowl off and the motor looked brand new. Much better than my existing motor - sort of embarrassed. Not a frayed wire, no splices, only a few plugs not hooked up in the front, but they look like tilt/trim connections.

I have jumped the starter with jumper cables just to check to see if it was seized - it doesn't appear to be. So next I set out to find a way to start it with muffs to see if it will run at all. I took the plugs out, they looked good but I bought some new ones just in case (all done). Checked the lower gear oil and decided to drain and put some new stuff in (all done). Took one of my batteries out of the fishing boat and hooked them to the hot and ground wires from the motor. Then it hit me. How do I turn a key that I don't have? I've been searching for a wiring diagram that looks like what I have, but I cannot find anything 'exactly' like it and I don't want to 'fry' anything.

My Model is: 706E91C. (serial number: 018141)
What I'm thinking might be my important connections (on the same side behind the starter) have the following setup:

"Start" (Yellow/Red, Yellow) (currently Yellow/Red)
"Tach" (Gray, Purple) (currently Gray)
"STOP" (Black/Yellow, White) (currently Black/Yellow and disconnected as I was told that was for the 'kill switch')
"Choke" (Yellow/Black, Green) (currently Yellow/Black)
"Overheat" ( <forget>, Orange) (currently Orange)
"Positive" (Red/Purple, Red) (currently Red/Purple)
"Stop 2" (Blue/Black, Blue) (currently Blue/Black)
--------------------
There are no wires on the opposite (left side when looking at it) side of this block of screwed in connections. I'm guessing that is where the wiring harness will be connected.


Does anyone know if there is a process by which to "jump" start this motor to see if it runs? I want to make sure it works before I go find all the controls and start removing my existing motor and equipment.

Thank you in advance.

Todd

 

[CaptnTony]

Ok, we got a bit 'risky' today and actually tested starting it by jumping the starter relay (I'm not sure that's what it's officially called, but it's the device in rear of motor back by the plugs on the same side as the starter). She turns over fine, but no spark (we think).

First thing we checked was the plugs. They WERE NOT new like I thought. I know we bought some for it, but must never have installed them. It's not been priority around here since we couldn't get on the water anyway because of covid-19. Anyway. Off to the parts store again. Bought NGK's again. Installed them and no start with these either.

First though was to check for spark. But these are plugs like I've not seen in my limited experience. The are flat on the 'hot' end. I'm not sure what to ground to in order to check for spark. So, since that is still being rattled around in my head, I found a link that said most of the 'spark' problems are rectifier issues. I think I found the rectifier in the rear. It's on the opposite side as the 'starter relay' but at the top of the motor. Mine appears to have a bit of yellow plexiglass over it. It doesn't look like anything is bad with it. It's clear, no burn marks, and I can see what appears to be the circuit board in there. But, I disconnected the battery and took the four wires off the motor connection panel on the same side of the motor. I noticed that the colors were yellow, yellow, gray, then red...BUT I forgot to take a picture of the dang thing before hand so I'm not certain WHICH yellow is first and which is second in the system. I think I got it in the correct order because I let the wires 'fall naturally' and they fell in yellow, yellow, gray, red order. If those two wires, coming from the same device can't be interchanged...WHO would have done that? I'm hoping it won't cause a problem when I reconnect them after testing tomorrow.

From the video that I saw, it looks like I'm supposed to test ohms on the yellow and yellow and then the gray and red and look for any 'unsettled' values or open circuits. Does that sound about right?

Thank you.

Todd

 

[jerryjerry05]

The "flat end plugs" they're called surface gap plugs.
You can check them the same way you check the other gapped plugs.

The FIRST thing you should do is a compression test.
IF? there's a comp problem you'll be wasting $$ on the ignition.

IF? it has good compression??? then you CAN make it run.

Without the key switch and safety switch you might not get spark??

Most no spark problems with Force outboards are stator related.

Get the shifter and wiring harness and key switch.

 

[CaptnTony]

Thank you for the information.

I did buy an inline plug tester this morning and didn't get any spark what-so-ever. Tried the tester, 'test the tester', on a pickup here and it definitely showed the spark vividly.

My plan is to test the components individually for now to see if they are in working order and 'should' work if all other things were in place. I'll also check compression. I have to head to my house to get that tool though (1.5 hrs away) and the closest auto store / car parts department is about 45 minutes from here.

 

[jerryjerry05]

IF???? it ran before?
Then what's different now??
Missing parts, harness, key switch, shifter and kill switch.
Add these and I bet it runs.

Google "starting an outboard without a key"
I know there's some videos that show how.