New Boat Owner..Seeking help, outboard starts only sometimes

[tyboatguy]

Hello all,
I recently bought a used boat with a 70hp Johnson outboard. It was started in the driveway when i purchased it and it started great for me the first time i took it out. It now seems really hit or miss if it will start. There is a brand new battery with tons of power everything cranks over really well but it wont actually completely fire up sometimes.
Other times it will start instantly 10 times in a row.
when its running everything seems really good and it runs well.
I am wondering if it could be a faulty killswitch problem? I am just looking for any suggestions of simple fixes it could be before having to take it in. Any help is greatly appreciated.
Thank you in advance!

 

[alldodge]

Does sound like an intermittent electrical issue, and those are hard to find. Assuming its a 2 cycle, the kill switch grounds the magneto. Grounding of the magneto can also be done anywhere along the way the wire travels, or even a bad switch.

Could also be a loose connection

Only way to fix is start going thru every connection until its found. A good volt ohm meter is the way to go

 

[tyboatguy]

Thank you Alldodge. I will go through the connections starting at the killswitch and see how i make out. Thanks for the response

 

[F_R]

What year is your 70?

 

[tyboatguy]

its a 1989

 

[jakedaawg]

I wonder if you know how to start it properly. Dont take offense, every season this happens that someone doesnt know there is a throttle advance, or does not know they have to push in and hold in the key for enrichment to happen.

there is a sticky at top of forum with a decent how to start my motor list.

 

[Tim Frank]

^^^^ +1

 

[tyboatguy]

Thanks jakedaawg and Tim Frank no offense taken. I will re-read that forum but I do believe I am starting it correctly with the throttle advancement lever and pushing the key in.
Sometimes it will start instantly, I will let it run or take it for a 10 min drive. get back to the dock turn it off, it will sometimes start again instantly a few times in a row and sometimes wont crank over again but the flywheel will spin no problem and water will be streaming out it just wont completely fire up.

 

[jakedaawg]

Well, good then. To rule out spark, find the amphenol connector at power pack. When you are having the issue test for spark. If no spark then when you are having the issue seperate the amphenol plug and jump all wires that are not blk/yel. Leave the blk/yel open. Do you now have spark? If so test key switch as per sticky at top of forum. Test harness from switch to pack.

 

[jakedaawg]

The above assumes you use an open air gap spark tester set to 7/16" and check on all three wires.

If no spark report back and s9meone will give you next steps.

 

[oldboat1]

like this one:


If you are doing a lot of cranking (that's turning the engine over without it starting), you may be wearing down the battery to the point where the motor is not turning over fast enough.

 

[dingbat]

Next time it will not start, pull a plug wire and check for spark.

If you have spark, you’ve eliminated the kill and neutral switch.

Put a meter on the shift switch to make sure it’s operational.

 

[tyboatguy]

Thanks everyone. I took apart the shift controls cleaned all the wire connections and tightened the ignition. Used it all day yesterday without any issue so hoping that has fixed the issue.