1987 Force 125 hp won't start

sergioy

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I've been posting on here about one problem or another about this particular motor. I have corrected everything up to this point, Now I have hit another roadblock, When I turn the key to start, the starter turns the flywheel, but nothing else. So not sure what to check next. The choke seems to be working properly.
 

Jiggz

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Oct 23, 2009
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The best way to check for sparks is using an inline-spark tester. It's available on auto parts store or even at walmart. If you have sparks, then the next thing to do is to get a small spray bottle and fill it up with fuel oil mix (50:1 ratio) and have someone crank over the motor while you spray into each of the carbs. You will need to remove the air covers to do this. The motor should at least "cough" or would try to start. If it does then you have fuel or carb related problem.
 

sergioy

Petty Officer 1st Class
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Apr 14, 2003
Messages
376
The best way to check for sparks is using an inline-spark tester. It's available on auto parts store or even at walmart. If you have sparks, then the next thing to do is to get a small spray bottle and fill it up with fuel oil mix (50:1 ratio) and have someone crank over the motor while you spray into each of the carbs. You will need to remove the air covers to do this. The motor should at least "cough" or would try to start. If it does then you have fuel or carb related problem.
Tanks Jiggz, I will try that. One other thing that confuses me about this motor is the spark plugs. when I look them up on this site, I get the NGK BUHX with the normal arch to adjust the gap, but the ones that are currently on the motor are the same, but they just have a flat bottom. So not sure which ones I should have.
 

Jiggz

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No Title

You should have the flat bottom gapless type if you have the correct BUHX. Like this one.

photo239863.jpg
 

sergioy

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Apr 14, 2003
Messages
376
You should have the flat bottom gapless type if you have the correct BUHX. Like this one.

I want to go ahead and buy some from this site, but the picture they are showing for BUHX are the gapped typed. So not sure if they are just not showing me the right ones on the pic.
 

sergioy

Petty Officer 1st Class
Joined
Apr 14, 2003
Messages
376
The best way to check for sparks is using an inline-spark tester. It's available on auto parts store or even at walmart. If you have sparks, then the next thing to do is to get a small spray bottle and fill it up with fuel oil mix (50:1 ratio) and have someone crank over the motor while you spray into each of the carbs. You will need to remove the air covers to do this. The motor should at least "cough" or would try to start. If it does then you have fuel or carb related problem.
Jiggsz - I have just confirmed that I am getting no spark on any of the 4 plugs, so what next?
 

Jiggz

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3,817
If you are not getting any spark on all four, do the following:
1. Make sure the safety lanyard switch is properly set. There should be some kind of key or chain that is inserted for this switch. The intent of the switch is to have the lanyard attached to the driver/boater and if accidentally thrown overboard will kill the motor by pulling the inserted key off the switch. If this is inserted properly, you need to disconnect one of the white wire from the terminal inside the cowling. Try again. If there's still no spark on all four, then check the resistance of the stator wires (blue and yellow and there are two sets). The resistance should be around 680~800 ohms or you can check output voltages from this set of wires while cranking and you should get approx. 180+ p-p. This should be enough to get you started. Make sure you have an electrical diagram to work with.
 

sergioy

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I ignored this for a few months and finally called a travelling mechanic that also works on boats and he found a bad ground. after that it fired right up.
 

Jiggz

Captain
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Oct 23, 2009
Messages
3,817
Thanks for the update. I wish the mechanic had been more specific. If there is one thing that will make a motor like this to have no spark is usually the kill switch which grounds the CDMs to shut off the engine.
 
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