Yamaha 1998 8 HP 2 stroke, weak spark

Charlie Hull

Recruit
Joined
Nov 28, 2017
Messages
1
My son has an old Yamaha (1998) 8HP outboard.. We recently replaced the fuel with new rec gas, installed a new fuel line and filter. Yesterday it was difficult to start, but once started, it ran perfect. We went about a half mile and shutt down to fish. The motor would not start. We rowed back. We bought new plugs, installed them. I saw a spark on the plug. With plug removed, twice. I'm wondering if the spark is weak? Starting fluid would not get the motor to fire. We removed the engine to his house, and after multiple pulls it started and ran great, no starting fluid used. The motor is stored by salt water. It has crimp connector on the coil and electric module. They didn't look corroded, but I was thinking of soldering the wires. Could the flywheel magnet be weak? The coil weak? I have a multimeter. What perplexed me is why the starting fluid will not get the engine to kick. Once we get it running, it runs great. Does either need a hot spark?
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,468
Ayuh,.... Welcome Aboard Charlie,..... I'll let this run a day or so in this forum, but I honestly think this belongs in the Yamaha Outboard forum,....

Even though electrical in nature, the ignition is very motor related,....

Or just let 1 of Us Mod's know, 'n it'll get moved there for ya,....
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,468
Ok,... Lets try in here, the Yamaha forum,....
 

tommarvin

Ensign
Joined
Nov 22, 2015
Messages
999
Yes its best to solder wires and shrink tube over them for protection
If you have carbs you should remove them take it/them apart and clean it, if you wreck any gaskets get new gaskets online.
You should get a spark tester to see if spark will jump 3/8-1/2 inch.
Theres no two stroke oil in starter fluid, you dont want to scorch your cylinder walls or rings. Try not to use it.
Odd's say it's a dirty carb, if you have a Welch plug remove it theirs a lot of little holes in there.
 
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