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Outboard won’t start

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Frustradedashell

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I have a Johnson 70HP 2 stroke, triple carb.

i have replaced the impeller this spring. Carbs have been rebuilt. New fuel lines and in line filter. New spark plugs.

boat fires up on muffs and in the lake first turn of the key. But after it runs and is warmed up it won’t start again if you shut it off.. I have been stranded twice now on the lake now. Getting pretty frustrated with it. Any ideas what might cause this to happen?
 
Check your compression and spark when it won't start. Spark should jump a 7/16" open air gap on a tester.
 
What year is it? Model #? Does it restart once it cools off? When it does restart, did you need to choke it?
 
I don’t have a compression tester but I will work on borrowing one to check it. If I have low compression is that a lost cause at that point? Warped head? If I lose spark in a cylinder would that mean the power pack needs replaced?

The ID plate does not have a year stamped on it but assuming it’s the original motor the registration says 1980. Model # off of the engine is J70ELCSA.

Usually when I start it on the muffs I don’t need to choke it. It fired right up. When I put it in the lake the first time it fired up no choke. Second time I put it in I had to choke it but still fired right up. The lake is about a 45 minute drive home plus about an hour of getting towed back to the launch and loading up. When I got home the boat fired up.

I did a test test at the house the next day. On the muffs I let it run for about 15 minutes. Enough to get everything warmed up. I shut it down waited a couple minutes and tried to start and it wouldn’t fire. I walked away for awhile as I had other stuff to do, but later that evening I turned it over out of curiosity and it fired up again no choke.

I almost forgot that last time I was on the lake the shift linkage was out of place a little bit, when I tried to start it it was turning the prop and moving the boat. Usually if it’s in gear it won’t even turn over, it has to be in neutral. Could the shift linkage be kicking in a kill switch if not coming back to proper position?
 
I took the boat out again this weekend. It fired right up at the dock, but had new symptoms. It was running dogged down the entire time. I pushed the throttle forward to its first locking position and it would run ok but not as much power as usual, and if I tried to rev it up it would die down. In neutral if I pulled the fast idle up it would rev up fine.

This is time I had a trolling motor with me and spent about 2 hours fishing before I tried to start the motor again. It actually fired right up. But ran dogged down the entire way back to the dock again.
 
Mixing gas / oil at 50:1 ratio ?-----Water pump working properly.-----Battery load tested.-----Starter motor taken apart and inspected ?
 
Frustradedashell said:
I don’t have a compression tester but I will work on borrowing one to check it. If I have low compression is that a lost cause at that point? Warped head? If I lose spark in a cylinder would that mean the power pack needs replaced?

The ID plate does not have a year stamped on it but assuming it’s the original motor the registration says 1980. Model # off of the engine is J70ELCSA.

Usually when I start it on the muffs I don’t need to choke it. It fired right up. When I put it in the lake the first time it fired up no choke. Second time I put it in I had to choke it but still fired right up. The lake is about a 45 minute drive home plus about an hour of getting towed back to the launch and loading up. When I got home the boat fired up.

I did a test test at the house the next day. On the muffs I let it run for about 15 minutes. Enough to get everything warmed up. I shut it down waited a couple minutes and tried to start and it wouldn’t fire. I walked away for awhile as I had other stuff to do, but later that evening I turned it over out of curiosity and it fired up again no choke.

I almost forgot that last time I was on the lake the shift linkage was out of place a little bit, when I tried to start it it was turning the prop and moving the boat. Usually if it’s in gear it won’t even turn over, it has to be in neutral. Could the shift linkage be kicking in a kill switch if not coming back to proper position?
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I have on other types of motors experienced when you do not have to choke a cold engine to start it is flooding,getting too much fuel right away.You may want to check your plugs right after it starts and see how wet they are and when it stalls or right after you shut it off after running a bit.
 
1980 70hp Evinrude...... Check the stator under the flywheel. There are 3 larger coils sealed inside that green ring that provide the proper AC voltage top the powerpack capacitor, needed to energize the pack. If any of those coils are melting down, dripping a sticky looking substance down on the powerhead area... that results in a voltage drop to the pack which in turn results in erratic ignition and eventually no ignition.

Should this condition exist... replace the stator.

A stator in this condition would function normally when cold (for awhile), but when hot it becomes a faulty component.
 
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