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92 Nissan 70hp NS70A2

Wannabeboater

New member
Got some firing issues, pretty much the lack of. I have an ohm meter and need to know the exact way to check the power pack and possibly the stator. I did notice that one of the spark plug boots was lacking a clip inside. I found that to be abnormal. So i removed the boot and fish out the coil looking clip which was pretty corroded, i cleaned it as best i could. The plug wire i took the boot off of was corroded back to the power pack as well. I did pop the fly wheel off to take a look at the stator to see if it may be corroded as well, thinking that may be one of the reasons for no spark. But it was pretty clean. Any help would be appreciated!
 
The 70A2 is from the 1980's, into the very early 90's, and is obsolete, so proceed carefully. If it has been run in saltwater a lot, there may be unrepairable corrosion issues.

There is no water pump kit available any more, but the bare impeller is being produced again.
No carb kits available any more, so once that's a problem, or you need water pump parts, the motor is scrap.

That motor does not have a stator. The trigger coil and exciter coil can be checked with an analog -- not digital -- ohm meter. Exciter should be somewhere around 200 ohms. Pulser maybe about 40 ohms.

The combined CD and ignition module can be checked, also with an analog ohm meter. A DVA can also be used to check for functional pulses from the exciter (about 140 DVA) and trigger (about 5 DVA) to the CD. Did you check for ignition with a spark tester? If not, start there. Output side of the coils (plug wires) is usually at least 4K ohms.

Most problems with these are fuel, not ignition. Since carb kits are NLA, the best you can do for the carbs on these is to carefully disassemble them, and do a Proper cleaning in carb dip. If gaskets are brittle or damaged, you will need to cut new ones by hand, and if a float needle is shot, you may be able to match one up from some other small motor, by visiting a helpful NAPA... if they have an old timer behind the counter, who is willing to look up a lot of possibilities.

From your description of the plug wires, you will need new wires and plug caps at a minimum.
 
Would it be sufficient to check the coils from the wires (red, black and blue)? I did check the resistance on both, one of them from under the flywheel, which were the red and black wires. I got a reading of 250 ohms. I could not trace the exact location of the blue wire. But from the plug that these wires (red, black, & blue) run to, on the red and black I got the same, 250 ohms. But the black and blue I only got 10 ohms. I used this link to help http://www.go2marine.com/productcenters/electrical/Tohatsu-Nissan.pdf but it does not tell me what to expect when I get the reading of 10 ohms!
 
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