evinrude dies after warm up

thejeepster02

Petty Officer 2nd Class
Joined
Jul 22, 2004
Messages
129
Hi Folks<br />I have a 1972 100hp Evinrude, Starts and runs great. after about 10 min. it will die. Starts right up again and dies after 3-5 seconds. did this several times. same thing.<br /><br />Waited till the next day, did the exact same thing, ran good till it warmed up.
 

thejeepster02

Petty Officer 2nd Class
Joined
Jul 22, 2004
Messages
129
Re: evinrude dies after warm up

Extra Info, This is all at a med. Idle speed
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: evinrude dies after warm up

When it starts to die, give the primer bulb a couple of squeezes. If the engine picks up, you have a fuel delivery problem. Clogged pickup in the tank, bad fuel pump, leaking fuel line fittings, to name just a few. This all assumes the engine isn't overheating and that you have good spark on all cylinders.
 

Kev

Seaman
Joined
May 15, 2005
Messages
61
Re: evinrude dies after warm up

It could also be a bad coil. Do a visual inspection of the coils. None should look cracked or "exploded." A bad coil can stop sparking or short out when hot, then work again when cooled off. When the engine is in its "dying" mode where it won't run for more than 3-5 seconds, do a spark test on each plug wire. Spark testers are easy to find and cheap. The spark should be blue and jump approximately 1/2" with no problem.<br /><br />Also, have you tried pulling the spark plug wires one-by-one to see if one cylinder is not firing? If you're dropping a cylinder, when you pull that plug wire, the engine will have no change in how it runs. If the engine lags or dies, then that cylinder is firing. Pulling plug wires may be tricky to do when the engine is in it's "dying" mode, but it can tell you which coil/cylinder to check. Wear gloves and use well-insulated pliers if you can.<br /><br />If it's not a fuel problem as Upinsmoke described, my money's on a bad coil.<br /><br />Good Luck,<br />Kev
 

thejeepster02

Petty Officer 2nd Class
Joined
Jul 22, 2004
Messages
129
Re: evinrude dies after warm up

Thanks<br />Im not a mechanic, but when a engine is cold, dosnt it require MORE gas?<br /><br />Thants why I didnt think it was a fuel problem.
 

Kev

Seaman
Joined
May 15, 2005
Messages
61
Re: evinrude dies after warm up

Technically an engine likes a "richer" (higher fuel to air ratio) mixture when cold. That is why you choke the engine when it is cold. This is not the same as saying it requires "more gas" (a larger quantity of gas).<br /><br />Have you tried any of the suggestions to diagnose your motor? Results?<br /><br />I think you'll find we've probably already covered the likely causes.<br /><br />Let us know what you find.<br /><br />Good Luck,<br />Kev
 
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